title: History of Earth

text: Oxygen accumulation from photosynthesis resulted in the formation of an ozone layer that absorbed much of the Sun's ultraviolet radiation, meaning unicellular organisms that reached land were less likely to die, and prokaryotes began to multiply and become better adapted to survival out of the water. Prokaryote lineages had probably colonized the land as early as 2.6 Ga even before the origin of the eukaryotes. For a long time, the land remained barren of multicellular organisms. The supercontinent Pannotia formed around 600 Ma and then broke apart a short 50 million years later. Fish, the earliest vertebrates, evolved in the oceans around 530 Ma. A major extinction event occurred near the end of the Cambrian period, which ended 488 Ma.


title: History of Earth

text: Several hundred million years ago, plants (probably resembling algae) and fungi started growing at the edges of the water, and then out of it. The oldest fossils of land fungi and plants date to 480–460 Ma, though molecular evidence suggests the fungi may have colonized the land as early as 1000 Ma and the plants 700 Ma. Initially remaining close to the water's edge, mutations and variations resulted in further colonization of this new environment. The timing of the first animals to leave the oceans is not precisely known: the oldest clear evidence is of arthropods on land around 450 Ma, perhaps thriving and becoming better adapted due to the vast food source provided by the terrestrial plants. There is also unconfirmed evidence that arthropods may have appeared on land as early as 530 Ma.


title: History of Earth

text: At the end of the Ordovician period, 443 Ma, additional extinction events occurred, perhaps due to a concurrent ice age. Around 380 to 375 Ma, the first tetrapods evolved from fish. Fins evolved to become limbs that the first tetrapods used to lift their heads out of the water to breathe air. This would let them live in oxygen-poor water, or pursue small prey in shallow water. They may have later ventured on land for brief periods. Eventually, some of them became so well adapted to terrestrial life that they spent their adult lives on land, although they hatched in the water and returned to lay their eggs. This was the origin of the amphibians. About 365 Ma, another period of extinction occurred, perhaps as a result of global cooling. Plants evolved seeds, which dramatically accelerated their spread on land, around this time (by approximately 360 Ma).


title: History of Earth

text: About 20 million years later (340 Ma), the amniotic egg evolved, which could be laid on land, giving a survival advantage to tetrapod embryos. This resulted in the divergence of amniotes from amphibians. Another 30 million years (310 Ma) saw the divergence of the synapsids (including mammals) from the sauropsids (including birds and reptiles). Other groups of organisms continued to evolve, and lines diverged—in fish, insects, bacteria, and so on—but less is known of the details.


title: History of Earth

text: After yet another, the most severe extinction of the period (251~250 Ma), around 230 Ma, dinosaurs split off from their reptilian ancestors. The Triassic–Jurassic extinction event at 200 Ma spared many of the dinosaurs, and they soon became dominant among the vertebrates. Though some mammalian lines began to separate during this period, existing mammals were probably small animals resembling shrews.


title: History of Earth

text: The boundary between avian and non-avian dinosaurs is not clear, but "Archaeopteryx", traditionally considered one of the first birds, lived around 150 Ma.


title: History of Earth

text: The earliest evidence for the angiosperms evolving flowers is during the Cretaceous period, some 20 million years later (132 Ma).


title: History of Earth

text: The first of five great mass extinctions was the Ordovician-Silurian extinction. Its possible cause was the intense glaciation of Gondwana, which eventually led to a snowball earth. 60% of marine invertebrates became extinct and 25% of all families.


title: History of Earth

text: The second mass extinction was the Late Devonian extinction, probably caused by the evolution of trees, which could have led to the depletion of greenhouse gases (like ) or the eutrophication of water. 70% of all species became extinct.


title: History of Earth

text: The third mass extinction was the Permian-Triassic, or the Great Dying, event was possibly caused by some combination of the Siberian Traps volcanic event, an asteroid impact, methane hydrate gasification, sea level fluctuations, and a major anoxic event. Either the proposed Wilkes Land crater in Antarctica or Bedout structure off the northwest coast of Australia may indicate an impact connection with the Permian-Triassic extinction. But it remains uncertain whether either these or other proposed Permian-Triassic boundary craters are either real impact craters or even contemporaneous with the Permian-Triassic extinction event. This was by far the deadliest extinction ever, with about 57% of all families and 83% of all genera killed.


title: History of Earth

text: The fourth mass extinction was the Triassic-Jurassic extinction event in which almost all synapsids and archosaurs became extinct, probably due to new competition from dinosaurs.


title: History of Earth

text: The fifth and most recent mass extinction was the Cretaceous-Paleogene extinction event. In 66 Ma, a asteroid struck Earth just off the Yucatán Peninsula—somewhere in the southwestern tip of then Laurasia—where the Chicxulub crater is today. This ejected vast quantities of particulate matter and vapor into the air that occluded sunlight, inhibiting photosynthesis. 75% of all life, including the non-avian dinosaurs, became extinct, marking the end of the Cretaceous period and Mesozoic era.


title: History of Earth

text: The first true mammals evolved in the shadows of dinosaurs and other large archosaurs that filled the world by the late Triassic. The first mammals were very small, and were probably nocturnal to escape predation. Mammal diversification truly began only after the Cretaceous-Paleogene extinction event. By the early Paleocene the earth recovered from the extinction, and mammalian diversity increased. Creatures like "Ambulocetus" took to the oceans to eventually evolve into whales, whereas some creatures, like primates, took to the trees. This all changed during the mid to late Eocene when the circum-Antarctic current formed between Antarctica and Australia which disrupted weather patterns on a global scale. Grassless savanna began to predominate much of the landscape, and mammals such as "Andrewsarchus" rose up to become the largest known terrestrial predatory mammal ever, and early whales like "Basilosaurus" took control of the seas.


title: History of Earth

text: The evolution of grasses brought a remarkable change to the Earth's landscape, and the new open spaces created pushed mammals to get bigger and bigger. Grass started to expand in the Miocene, and the Miocene is where many modern- day mammals first appeared. Giant ungulates like "Paraceratherium" and "Deinotherium" evolved to rule the grasslands. The evolution of grass also brought primates down from the trees, and started human evolution. The first big cats evolved during this time as well. The Tethys Sea was closed off by the collision of Africa and Europe.


title: History of Earth

text: The formation of Panama was perhaps the most important geological event to occur in the last 60 million years. Atlantic and Pacific currents were closed off from each other, which caused the formation of the Gulf Stream, which made Europe warmer. The land bridge allowed the isolated creatures of South America to migrate over to North America, and vice versa. Various species migrated south, leading to the presence in South America of llamas, the spectacled bear, kinkajous and jaguars.


title: History of Earth

text: Three million years ago saw the start of the Pleistocene epoch, which featured dramatic climatic changes due to the ice ages. The ice ages led to the evolution of modern man in Saharan Africa and expansion. The mega-fauna that dominated fed on grasslands that, by now, had taken over much of the subtropical world. The large amounts of water held in the ice allowed for various bodies of water to shrink and sometimes disappear such as the North Sea and the Bering Strait. It is believed by many that a huge migration took place along Beringia which is why, today, there are camels (which evolved and became extinct in North America), horses (which evolved and became extinct in North America), and Native Americans. The ending of the last ice age coincided with the expansion of man, along with a massive die out of ice age mega-fauna. This extinction is nicknamed "the Sixth Extinction".


title: History of Earth

text: A small African ape living around 6 Ma was the last animal whose descendants would include both modern humans and their closest relatives, the chimpanzees. Only two branches of its family tree have surviving descendants. Very soon after the split, for reasons that are still unclear, apes in one branch developed the ability to walk upright. Brain size increased rapidly, and by 2 Ma, the first animals classified in the genus "Homo" had appeared. Of course, the line between different species or even genera is somewhat arbitrary as organisms continuously change over generations. Around the same time, the other branch split into the ancestors of the common chimpanzee and the ancestors of the bonobo as evolution continued simultaneously in all life forms.


title: History of Earth

text: The ability to control fire probably began in "Homo erectus" (or "Homo ergaster"), probably at least 790,000 years ago but perhaps as early as 1.5 Ma. The use and discovery of controlled fire may even predate "Homo erectus". Fire was possibly used by the early Lower Paleolithic (Oldowan) hominid "Homo habilis" or strong australopithecines such as "Paranthropus."


title: History of Earth

text: It is more difficult to establish the origin of language; it is unclear whether "Homo erectus" could speak or if that capability had not begun until "Homo sapiens". As brain size increased, babies were born earlier, before their heads grew too large to pass through the pelvis. As a result, they exhibited more plasticity, and thus possessed an increased capacity to learn and required a longer period of dependence. Social skills became more complex, language became more sophisticated, and tools became more elaborate. This contributed to further cooperation and intellectual development. Modern humans ("Homo sapiens") are believed to have originated around 200,000 years ago or earlier in Africa; the oldest fossils date back to around 160,000 years ago.


title: History of Earth

text: The first humans to show signs of spirituality are the Neanderthals (usually classified as a separate species with no surviving descendants); they buried their dead, often with no sign of food or tools. However, evidence of more sophisticated beliefs, such as the early Cro-Magnon cave paintings (probably with magical or religious significance) did not appear until 32,000 years ago. Cro-Magnons also left behind stone figurines such as Venus of Willendorf, probably also signifying religious belief. By 11,000 years ago, "Homo sapiens" had reached the southern tip of South America, the last of the uninhabited continents (except for Antarctica, which remained undiscovered until 1820 AD). Tool use and communication continued to improve, and interpersonal relationships became more intricate.


title: History of Earth

text: Throughout more than 90% of its history, "Homo sapiens" lived in small bands as nomadic hunter-gatherers. As language became more complex, the ability to remember and communicate information resulted, according to a theory proposed by Richard Dawkins, in a new replicator: the meme. Ideas could be exchanged quickly and passed down the generations. Cultural evolution quickly outpaced biological evolution, and history proper began. Between 8500 and 7000 BC, humans in the Fertile Crescent in the Middle East began the systematic husbandry of plants and animals: agriculture. This spread to neighboring regions, and developed independently elsewhere, until most "Homo sapiens" lived sedentary lives in permanent settlements as farmers. Not all societies abandoned nomadism, especially those in isolated areas of the globe poor in domesticable plant species, such as Australia. However, among those civilizations that did adopt agriculture, the relative stability and increased productivity provided by farming allowed the population to expand.


title: History of Earth

text: Agriculture had a major impact; humans began to affect the environment as never before. Surplus food allowed a priestly or governing class to arise, followed by increasing division of labor. This led to Earth's first civilization at Sumer in the Middle East, between 4000 and 3000 BC. Additional civilizations quickly arose in ancient Egypt, at the Indus River valley and in China. The invention of writing enabled complex societies to arise: record-keeping and libraries served as a storehouse of knowledge and increased the cultural transmission of information. Humans no longer had to spend all their time working for survival, enabling the first specialized occupations (e.g. craftsmen, merchants, priests, etc.). Curiosity and education drove the pursuit of knowledge and wisdom, and various disciplines, including science (in a primitive form), arose. This in turn led to the emergence of increasingly larger and more complex civilizations, such as the first empires, which at times traded with one another, or fought for territory and resources.


title: History of Earth

text: By around 500 BC, there were advanced civilizations in the Middle East, Iran, India, China, and Greece, at times expanding, at times entering into decline. In 221 BC, China became a single polity that would grow to spread its culture throughout East Asia, and it has remained the most populous nation in the world. During this period, famous Hindu texts known as vedas came in existence in Indus valley civilization. This civilization developed in warfare, arts, science, mathematics and in architect. The fundamentals of Western civilization were largely shaped in Ancient Greece, with the world's first democratic government and major advances in philosophy and science, and in Ancient Rome with advances in law, government, and engineering. The Roman Empire was Christianized by Emperor Constantine in the early 4th century and declined by the end of the 5th. Beginning with the 7th century, Christianization of Europe began, and since at least the 4th century Christianity has played a prominent role in the shaping of Western civilization. In 610, Islam was founded and quickly became the dominant religion in Western Asia. The House of Wisdom was established in Abbasid-era Baghdad, Iraq. It is considered to have been a major intellectual center during the Islamic Golden Age, where Muslim scholars in Baghdad and Cairo flourished from the ninth to the thirteenth centuries until the Mongol sack of Baghdad in 1258 AD. In 1054 AD the Great Schism between the Roman Catholic Church and the Eastern Orthodox Church led to the prominent cultural differences between Western and Eastern Europe.


title: History of Earth

text: In the 14th century, the Renaissance began in Italy with advances in religion, art, and science. At that time the Christian Church as a political entity lost much of its power. In 1492, Christopher Columbus reached the Americas, initiating great changes to the new world. European civilization began to change beginning in 1500, leading to the scientific and industrial revolutions. That continent began to exert political and cultural dominance over human societies around the world, a time known as the Colonial era (also see Age of Discovery).


title: History of Earth

text: Change has continued at a rapid pace from the mid-1940s to today. Technological developments include nuclear weapons, computers, genetic engineering, and nanotechnology. Economic globalization, spurred by advances in communication and transportation technology, has influenced everyday life in many parts of the world. Cultural and institutional forms such as democracy, capitalism, and environmentalism have increased influence. Major concerns and problems such as disease, war, poverty, violent radicalism, and recently, human-caused climate change have risen as the world population increases.


title: History of Earth

text: In 1957, the Soviet Union launched the first artificial satellite into orbit and, soon afterward, Yuri Gagarin became the first human in space. Neil Armstrong, an American, was the first to set foot on another astronomical object, the Moon. Unmanned probes have been sent to all the known planets in the Solar System, with some (such as the two Voyager spacecraft) having left the Solar System. Five space agencies, representing over fifteen countries, have worked together to build the International Space Station. Aboard it, there has been a continuous human presence in space since 2000. The World Wide Web became a part of everyday life in the 1990s, and since then has become an indispensable source of information in the developed world.


title: The Tourist (2010 film)

text: The Tourist is a 2010 American romantic thriller film co-written and directed by Florian Henckel von Donnersmarck and starring Angelina Jolie, Johnny Depp, Paul Bettany, and Timothy Dalton. It is a remake of the 2005 French film "Anthony Zimmer". GK Films financed and produced the film, with Sony Pictures Worldwide Acquisitions releasing it in most countries through Columbia Pictures. The $100 million budget film went on to gross $278 million at the worldwide box office.


title: The Tourist (2010 film)

text: Despite negative reception from the critics, the film was nominated for three Golden Globes, with a debate arising over the question as to whether it was a comedy or a drama. Henckel von Donnersmarck repeatedly stated it was neither genre, calling it "a travel romance with thriller elements," but that if he had to choose between the two, he would choose comedy.


title: The Tourist (2010 film)

text: A British woman, Elise Clifton-Ward (Angelina Jolie), is being followed through downtown Paris by French police who are working with Scotland Yard under the direction of Inspector John Acheson (Paul Bettany). Acheson has spent years hunting Alexander Pearce, Elise's lover, who owes £744 million in back taxes, and is believed to have received plastic surgery to alter his appearance. He is also being hunted by Reginald Shaw (Steven Berkoff), a mobster from whom Pearce stole $2.3 billion. At a Parisian cafe, Elise receives written instructions from Pearce: board the train to Venice, Italy; pick out a man; and let the police believe that he is Pearce. Elise burns the note, evades the police, and boards the train.


title: The Tourist (2010 film)

text: On the train, Elise selects Frank Tupelo (Johnny Depp), a mathematics teacher from a community college in Wisconsin. Acheson salvages information about the plan from the remains of the burned note. Aware of her location, but not of the ruse, a policeman on Shaw's payroll alerts Shaw that Pearce is on the train to Venice with Elise. Shaw immediately proceeds to Venice.


title: The Tourist (2010 film)

text: In Venice, Elise invites Frank to stay with her at the Hotel Danieli, where she receives instructions from Pearce to attend a ball. She abandons Frank, who is then chased by Shaw's men. While trying to escape, he is detained by the Italian police, and a corrupt inspector attempts to turn him over to Shaw's men for a bounty. Elise rescues Frank just before he is handed over, leading Shaw's men on an extended boat chase before finally escaping. She leaves Frank at the airport with his passport and money, urging him to go home for his own safety.


title: The Tourist (2010 film)

text: Elise goes to see Acheson, who has come to Venice, and is revealed to be an undercover Scotland Yard agent who was under suspension for her suspected sympathies with Pearce. She agrees to participate in a sting operation to bring Pearce to justice. As she tries to find Pearce at the ball, a man places an envelope on her table and disappears into the crowd. She tries to follow him, but is stopped by Frank, who claims to be in love with her and invites her to dance. The police arrive and take Frank into protective custody. Elise reads the note and leaves in her boat, tailed by Shaw and the police.


title: The Tourist (2010 film)

text: When Elise gets to the house to which Pearce's note directed her, Shaw takes her hostage, threatening to harm her unless she reveals the location of a hidden safe where Pearce is keeping the stolen money. The police monitor the situation from outside, and Acheson repeatedly refuses to allow Italian police snipers to intervene to rescue Elise. While the police are distracted monitoring the situation, Frank escapes and confronts Shaw, claiming to be Pearce and offering to open the safe if Elise is allowed to leave. Shaw tells Frank to open the safe or he will have Elise tortured. Chief Inspector Jones arrives at the police stake-out, overrides Acheson, and orders the snipers to fire, killing Shaw and his men. Then, to Elise's obvious pleasure, Jones lifts her suspension and fires her.


title: The Tourist (2010 film)

text: Acheson receives a message that Pearce has been found nearby, but, on arrival, he learns the police have detained an Englishman who says he is only a tourist being paid to follow instructions and is not Pearce. Elise tells Frank that she loves him, but she also loves Pearce. Frank opens the safe by entering the correct code, revealing that he was Alexander Pearce all along. When the police come back and open the safe with explosives, they find a check for £744 million. Acheson wants to keep pursuing Pearce, but, since the taxes are now paid, Jones closes the case. Pearce and Elise sail away together.


title: The Tourist (2010 film)

text: The project went through a number of directorial and cast changes. Originally, Lasse Hallström was set to direct, with Charlize Theron to play the female lead. After Hallström left, allegedly over scheduling conflicts, Bharat Nalluri came on board, and then Tom Cruise was announced to play the male lead, though he was later replaced by Sam Worthington. When Jolie accepted her role, so did director Florian Henckel von Donnersmarck, but he, along with Worthington subsequently left, citing "creative differences". After many other directors were considered, including Alfonso Cuarón, Henckel von Donnersmarck returned, re-wrote the script in two weeks, and shot the film in 58 days (including 2nd unit days), with Johnny Depp as the male lead.


title: The Tourist (2010 film)

text: Filming began in Paris with Jolie on February 23, 2010, before moving to Venice, where Depp joined the production on March 1. French Minister of Culture Frédéric Mitterrand visited Florian Henckel von Donnersmarck on set when "The Tourist" was filming in Place Colette.


title: The Tourist (2010 film)

text: Henckel von Donnersmarck was assisted by stunt coordinator Simon Crane, who devised the boat action sequence. In the DVD director's commentary, Henckel von Donnersmarck recounts that the film's one action sequence was devised by Crane to allow for the speed limitations imposed on boats in Venice. This speed limit was strictly enforced by the Venetian authorities, and there was a policeman on set at all times to make sure no wave movement caused the pillars on which the palazzi are built to be exposed to oxygen. Henckel von Donnersmarck and Crane felt that if one boat was towing the other, this could perhaps be a realistic reason for a slow speed chase.


title: The Tourist (2010 film)

text: The whole film was made in only a little over 11 months, counting from the day Henckel von Donnersmarck came on board to re-write and direct to the day of the premiere in New York. It had to be shot so quickly because Depp had to leave for Hawaii to start filming the fourth film of the "Pirates of the Caribbean" franchise. The reason post-production had to happen so quickly was because all commercially interesting release dates in 2011 were reserved for the potential start of "".


title: The Tourist (2010 film)

text: The film's Russian gangsters Virginsky (Igor Jijikine), Lebyadkin (Vladimir Orlov), Liputin (Vladimir Tevlovski), Fedka (Alec Utgoff), and Shigalyov (Mark Zak) all carry names from Fyodor Dostoyevsky's 1873 political novel "Demons". First-credited screenwriter and director Donnersmarck has talked of his childhood obsession with the Russian writer, and the Dostoyevskian theme of corrupt police and government resonates throughout the film.


title: The Tourist (2010 film)

text: On Rotten Tomatoes, the film has an approval rating of 20% based on 173 reviews, and an average rating of 4.4/10. The site's critical consensus reads: "The scenery and the stars are undeniably beautiful, but they can't make up for "The Tourist"s slow, muddled plot, or the lack of chemistry between Johnny Depp and Angelina Jolie." On Metacritic, the film has a weighted average score of 37 out of 100 based on 37 critics, indicating "generally unfavorable reviews". Audiences polled by CinemaScore gave the film an average grade of "B" on an A+ to F scale.


title: The Tourist (2010 film)

text: Roger Ebert gave the film 2 out of 4 stars, saying "There's a way to make a movie like "The Tourist", but Florian Henckel von Donnersmarck doesn't find that way." Peter Travers of "Rolling Stone" gave the film 0 out of 4 stars, and put the film on his list of the top 10 worst films of 2010.


title: The Tourist (2010 film)

text: However, the film received good reviews in the German press, and Stephanie Zacharek, a Rotten Tomatoes Top Critic, listed the film as one of her "10 Best Movies of 2010." She called it "a visually sensuous picture made with tender attention to detail and an elegant, understated sense of humor".


title: The Tourist (2010 film)

text: Casey Burchby of DVD Talk acknowledged that the movie was "beautifully shot by the accomplished Oscar-winner John Seale," but said that the "hastily-prepared film does not care one iota about its characters."


title: The Tourist (2010 film)

text: At the 2011 Golden Globe Awards, Ricky Gervais made fun of the film while he was presenting. After this, in a scripted, fictional encounter on the show "Life's Too Short", which was written by Gervais and Stephen Merchant, Johnny Depp reminded Gervais that the film was very successful, grossing $278 million, which was a dig aimed at Gervais, whose only two Hollywood films ("Ghost Town" and "The Invention of Lying") had grossed $27 million and $32 million, respectively.


title: The Tourist (2010 film)

text: The film was nominated for three Golden Globe Awards: Best Musical or Comedy, Best Actor – Musical or Comedy (Depp), and Best Actress – Musical or Comedy (Jolie). The fact that a film originally promoted as a romantic thriller was nominated in the comedy category garnered the film and the Golden Globes considerable mockery. It was later revealed that the film was originally submitted by the studio as a drama, but Henckel von Donnersmarck then told the HFPA that it should be categorized as a comedy. HFPA President Phil Berk said, "Given the differing opinions, we asked the studio to screen the film for us in advance, and collectively, we decided that the elements of preposterous fun lent the film more to a comedy than a straight drama category."


title: OLED

text: An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current. This organic layer is situated between two electrodes; typically, at least one of these electrodes is transparent. OLEDs are used to create digital displays in devices such as television screens, computer monitors, and portable systems such as smartphones and handheld game consoles. A major area of research is the development of white OLED devices for use in solid-state lighting applications.


title: OLED

text: There are two main families of OLED: those based on small molecules and those employing polymers. Adding mobile ions to an OLED creates a light-emitting electrochemical cell (LEC) which has a slightly different mode of operation. An OLED display can be driven with a passive-matrix (PMOLED) or active-matrix (AMOLED) control scheme. In the PMOLED scheme, each row and line in the display is controlled sequentially, one by one, whereas AMOLED control uses a thin-film transistor (TFT) backplane to directly access and switch each individual pixel on or off, allowing for higher resolution and larger display sizes.


title: OLED

text: OLED is fundamentally different from LED which is based on a p-n diode structure. In LEDs doping is used to create p- and n- regions by changing the conductivity of the host semiconductor. OLEDs do not employ a p-n structure. Doping of OLEDs is used to increase radiative efficiency by direct modification of the quantum-mechanical optical recombination rate. Doping is additionally used to determine the wavelength of photon emission.


title: OLED

text: An OLED display works without a backlight because it emits its own visible light. Thus, it can display deep black levels and can be thinner and lighter than a liquid crystal display (LCD). In low ambient light conditions (such as a dark room), an OLED screen can achieve a higher contrast ratio than an LCD, regardless of whether the LCD uses cold cathode fluorescent lamps or an LED backlight. OLED displays are made in the same way as LCDs, but after TFT (for active matrix displays), addressable grid (for passive matrix displays) or indium-tin oxide (ITO) segment (for segment displays) formation, the display is coated with hole injection, transport and blocking layers, as well with electroluminescent material after the first 2 layers, after which ITO or metal may be applied again as a cathode and later the entire stack of materials is encapsulated. The TFT layer, addressable grid or ITO segments serve as or are connected to the anode, which may be made of ITO or metal. OLEDs can be made flexible and transparent, with transparent displays being used in smartphones with optical fingerprint scanners and flexible displays being used in foldable smartphones.


title: OLED

text: André Bernanose and co-workers at the Nancy-Université in France made the first observations of electroluminescence in organic materials in the early 1950s. They applied high alternating voltages in air to materials such as acridine orange dye, either deposited on or dissolved in cellulose or cellophane thin films. The proposed mechanism was either direct excitation of the dye molecules or excitation of electrons.


title: OLED

text: In 1960, Martin Pope and some of his co-workers at New York University developed ohmic dark-injecting electrode contacts to organic crystals. They further described the necessary energetic requirements (work functions) for hole and electron injecting electrode contacts. These contacts are the basis of charge injection in all modern OLED devices. Pope's group also first observed direct current (DC) electroluminescence under vacuum on a single pure crystal of anthracene and on anthracene crystals doped with tetracene in 1963 using a small area silver electrode at 400 volts. The proposed mechanism was field-accelerated electron excitation of molecular fluorescence.


title: OLED

text: Pope's group reported in 1965 that in the absence of an external electric field, the electroluminescence in anthracene crystals is caused by the recombination of a thermalized electron and hole, and that the conducting level of anthracene is higher in energy than the exciton energy level. Also in 1965, Wolfgang Helfrich and W. G. Schneider of the National Research Council in Canada produced double injection recombination electroluminescence for the first time in an anthracene single crystal using hole and electron injecting electrodes, the forerunner of modern double-injection devices. In the same year, Dow Chemical researchers patented a method of preparing electroluminescent cells using high-voltage (500–1500 V) AC-driven (100–3000Hz) electrically insulated one millimetre thin layers of a melted phosphor consisting of ground anthracene powder, tetracene, and graphite powder. Their proposed mechanism involved electronic excitation at the contacts between the graphite particles and the anthracene molecules.


title: OLED

text: The first Polymer LED (PLED) to be created was by Roger Partridge at the National Physical Laboratory in the United Kingdom. It used a film of poly(N-vinylcarbazole) up to 2.2 micrometers thick located between two charge-injecting electrodes. The light generated was readily visible in normal lighting conditions though the polymer used had 2 limitations; low conductivity and the difficulty of injecting electrons. Later development of conjugated polymers would allow others to largely eliminate these problems. His contribution has often been overlooked due to the secrecy NPL imposed on the project. When it was patented in 1974 it was given a deliberately obscure "catch all" name while the government's Department for Industry tried and failed to find industrial collaborators to fund further development. As a result publication was delayed until 1983.


title: OLED

text: Chemists Ching Wan Tang and Steven Van Slyke at Eastman Kodak built the first practical OLED device in 1987. This device used a two-layer structure with separate hole transporting and electron transporting layers such that recombination and light emission occurred in the middle of the organic layer; this resulted in a reduction in operating voltage and improvements in efficiency.


title: OLED

text: Research into polymer electroluminescence culminated in 1990, with J. H. Burroughes "et al." at the Cavendish Laboratory at Cambridge University, UK, reporting a high-efficiency green light-emitting polymer-based device using 100nm thick films of poly(p-phenylene vinylene). Moving from molecular to macromolecular materials solved the problems previously encountered with the long-term stability of the organic films and enabled high-quality films to be easily made. Subsequent research developed multilayer polymers and the new field of plastic electronics and OLED research and device production grew rapidly. White OLEDs, pioneered by J. Kido "et al." at Yamagata University, Japan in 1995, achieved the commercialization of OLED-backlit displays and lighting.


title: OLED

text: In 1999, Kodak and Sanyo had entered into a partnership to jointly research, develop, and produce OLED displays. They announced the world's first 2.4-inch active-matrix, full-color OLED display in September the same year. In September 2002, they presented a prototype of 15-inch HDTV format display based on white OLEDs with color filters at the CEATEC Japan.


title: OLED

text: Manufacturing of small molecule OLEDs was started in 1997 by Pioneer Corporation, followed by TDK in 2001 and Samsung-NEC Mobile Display (SNMD), which later became one of the world's largest OLED display manufacturers - Samsung Display, in 2002.


title: OLED

text: The Sony XEL-1, released in 2007, was the first OLED television. Universal Display Corporation, one of the OLED materials companies, holds a number of patents concerning the commercialization of OLEDs that are used by major OLED manufacturers around the world.


title: OLED

text: On 5 December 2017, JOLED, the successor of Sony and Panasonic's printable OLED business units, began the world's first commercial shipment of inkjet-printed OLED panels.


title: OLED

text: A typical OLED is composed of a layer of organic materials situated between two electrodes, the anode and cathode, all deposited on a substrate. The organic molecules are electrically conductive as a result of delocalization of pi electrons caused by conjugation over part or all of the molecule. These materials have conductivity levels ranging from insulators to conductors, and are therefore considered organic semiconductors. The highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) of organic semiconductors are analogous to the valence and conduction bands of inorganic semiconductors.


title: OLED

text: Originally, the most basic polymer OLEDs consisted of a single organic layer. One example was the first light-emitting device synthesised by J. H. Burroughes "et al.", which involved a single layer of poly(p-phenylene vinylene). However multilayer OLEDs can be fabricated with two or more layers in order to improve device efficiency. As well as conductive properties, different materials may be chosen to aid charge injection at electrodes by providing a more gradual electronic profile, or block a charge from reaching the opposite electrode and being wasted. Many modern OLEDs incorporate a simple bilayer structure, consisting of a conductive layer and an emissive layer. Developments in OLED architecture in 2011 improved quantum efficiency (up to 19%) by using a graded heterojunction. In the graded heterojunction architecture, the composition of hole and electron-transport materials varies continuously within the emissive layer with a dopant emitter. The graded heterojunction architecture combines the benefits of both conventional architectures by improving charge injection while simultaneously balancing charge transport within the emissive region.


title: OLED

text: During operation, a voltage is applied across the OLED such that the anode is positive with respect to the cathode. Anodes are picked based upon the quality of their optical transparency, electrical conductivity, and chemical stability. A current of electrons flows through the device from cathode to anode, as electrons are injected into the LUMO of the organic layer at the cathode and withdrawn from the HOMO at the anode. This latter process may also be described as the injection of electron holes into the HOMO. Electrostatic forces bring the electrons and the holes towards each other and they recombine forming an exciton, a bound state of the electron and hole. This happens closer to the electron-transport layer part of the emissive layer, because in organic semiconductors holes are generally more mobile than electrons. The decay of this excited state results in a relaxation of the energy levels of the electron, accompanied by emission of radiation whose frequency is in the visible region. The frequency of this radiation depends on the band gap of the material, in this case the difference in energy between the HOMO and LUMO.


title: OLED

text: As electrons and holes are fermions with half integer spin, an exciton may either be in a singlet state or a triplet state depending on how the spins of the electron and hole have been combined. Statistically three triplet excitons will be formed for each singlet exciton. Decay from triplet states (phosphorescence) is spin forbidden, increasing the timescale of the transition and limiting the internal efficiency of fluorescent devices. Phosphorescent organic light-emitting diodes make use of spin–orbit interactions to facilitate intersystem crossing between singlet and triplet states, thus obtaining emission from both singlet and triplet states and improving the internal efficiency.


title: OLED

text: Indium tin oxide (ITO) is commonly used as the anode material. It is transparent to visible light and has a high work function which promotes injection of holes into the HOMO level of the organic layer. A second conductive (injection) layer is typically added, which may consist of , as the HOMO level of this material generally lies between the work function of ITO and the HOMO of other commonly used polymers, reducing the energy barriers for hole injection. Metals such as barium and calcium are often used for the cathode as they have low work functions which promote injection of electrons into the LUMO of the organic layer. Such metals are reactive, so they require a capping layer of aluminium to avoid degradation. Two secondary benefits of the aluminum capping layer include robustness to electrical contacts and the back reflection of emitted light out to the transparent ITO layer.


title: OLED

text: Experimental research has proven that the properties of the anode, specifically the anode/hole transport layer (HTL) interface topography plays a major role in the efficiency, performance, and lifetime of organic light-emitting diodes. Imperfections in the surface of the anode decrease anode-organic film interface adhesion, increase electrical resistance, and allow for more frequent formation of non-emissive dark spots in the OLED material adversely affecting lifetime. Mechanisms to decrease anode roughness for ITO/glass substrates include the use of thin films and self-assembled monolayers. Also, alternative substrates and anode materials are being considered to increase OLED performance and lifetime. Possible examples include single crystal sapphire substrates treated with gold (Au) film anodes yielding lower work functions, operating voltages, electrical resistance values, and increasing lifetime of OLEDs.


title: OLED

text: Single carrier devices are typically used to study the kinetics and charge transport mechanisms of an organic material and can be useful when trying to study energy transfer processes. As current through the device is composed of only one type of charge carrier, either electrons or holes, recombination does not occur and no light is emitted. For example, electron only devices can be obtained by replacing ITO with a lower work function metal which increases the energy barrier of hole injection. Similarly, hole only devices can be made by using a cathode made solely of aluminium, resulting in an energy barrier too large for efficient electron injection.


title: OLED

text: Balanced charge injection and transfer are required to get high internal efficiency, pure emission of luminance layer without contaminated emission from charge transporting layers, and high stability. A common way to balance charge is optimizing the thickness of the charge transporting layers but is hard to control. Another way is using the exciplex. Exciplex formed between hole-transporting (p-type) and electron-transporting (n-type) side chains to localize electron-hole pairs. Energy is then transferred to luminophore and provide high efficiency. An example of using exciplex is grafting Oxadiazole and carbazole side units in red diketopyrrolopyrrole-doped Copolymer main chain shows improved external quantum efficiency and color purity in no optimized OLED.


title: OLED

text: Organic small-molecule electroluminescent materials have the advantages of a wide variety, easy to purify, and strong chemical modifications. In order to make the luminescent materials to emit light as required, some chromophores or unsaturated groups such as alkene bonds and benzene rings will usually be introduced in the molecular structure design to change the size of the conjugation range of the material, so that the photophysical properties of the material changes. In general, the larger the range of π-electron conjugation system, the longer the wavelength of light emitted by the material. For instance, with the increase of the number of benzene rings, the fluorescence emission peak of benzene, naphthalene, anthracene, and butyl gradually red-shifted from 283 nm to 480 nm. Common organic small molecule electroluminescent materials include aluminum complexes, anthracenes, biphenyl acetylene aryl derivatives, coumarin derivatives, and various fluorochromes. Efficient OLEDs using small molecules were first developed by Ching W. Tang "et al." at Eastman Kodak. The term OLED traditionally refers specifically to this type of device, though the term SM-OLED is also in use.


title: OLED

text: Molecules commonly used in OLEDs include organometallic chelates (for example Alq, used in the organic light-emitting device reported by Tang "et al."), fluorescent and phosphorescent dyes and conjugated dendrimers. A number of materials are used for their charge transport properties, for example triphenylamine and derivatives are commonly used as materials for hole transport layers. Fluorescent dyes can be chosen to obtain light emission at different wavelengths, and compounds such as perylene, rubrene and quinacridone derivatives are often used. Alq has been used as a green emitter, electron transport material and as a host for yellow and red emitting dyes.


title: OLED

text: Because of the structural flexibility of small-molecule electroluminescent materials, thin films can be prepared by vacuum vapor deposition, which is more expensive and of limited use for large-area devices. The vacuum coating system, however, can make the entire process from film growth to OLED device preparation in a controlled and complete operating environment, helping to obtain uniform and stable films, thus ensuring the final fabrication of high-performance OLED devices.However, small molecule organic dyes are prone to fluorescence quenching in the solid state, resulting in lower luminescence efficiency. The doped OLED devices are also prone to crystallization, which reduces the luminescence and efficiency of the devices. Therefore, the development of devices based on small-molecule electroluminescent materials is limited by high manufacturing costs, poor stability, short life, and other shortcomings. Coherent emission from a laser dye-doped tandem SM-OLED device, excited in the pulsed regime, has been demonstrated. The emission is nearly diffraction limited with a spectral width similar to that of broadband dye lasers.


title: OLED

text: Researchers report luminescence from a single polymer molecule, representing the smallest possible organic light-emitting diode (OLED) device. Scientists will be able to optimize substances to produce more powerful light emissions. Finally, this work is a first step towards making molecule-sized components that combine electronic and optical properties. Similar components could form the basis of a molecular computer.


title: OLED

text: Polymer light-emitting diodes (PLED, P-OLED), also light-emitting polymers (LEP), involve an electroluminescent conductive polymer that emits light when connected to an external voltage. They are used as a thin film for full-spectrum colour displays. Polymer OLEDs are quite efficient and require a relatively small amount of power for the amount of light produced.


title: OLED

text: Vacuum deposition is not a suitable method for forming thin films of polymers. If the polymeric OLED films are made by vacuum vapor deposition, the chain elements will be cut off and the original photophysical properties will be compromised. However, polymers can be processed in solution, and spin coating is a common method of depositing thin polymer films. This method is more suited to forming large-area films than thermal evaporation. No vacuum is required, and the emissive materials can also be applied on the substrate by a technique derived from commercial inkjet printing. However, as the application of subsequent layers tends to dissolve those already present, formation of multilayer structures is difficult with these methods. The metal cathode may still need to be deposited by thermal evaporation in vacuum. An alternative method to vacuum deposition is to deposit a Langmuir-Blodgett film.


title: OLED

text: Typical polymers used in PLED displays include derivatives of poly("p"-phenylene vinylene) and polyfluorene. Substitution of side chains onto the polymer backbone may determine the colour of emitted light or the stability and solubility of the polymer for performance and ease of processing.


title: OLED

text: While unsubstituted poly(p-phenylene vinylene) (PPV) is typically insoluble, a number of PPVs and related poly(naphthalene vinylene)s (PNVs) that are soluble in organic solvents or water have been prepared via ring opening metathesis polymerization. These water-soluble polymers or conjugated poly electrolytes (CPEs) also can be used as hole injection layers alone or in combination with nanoparticles like graphene.


title: OLED

text: Phosphorescent organic light-emitting diodes use the principle of electrophosphorescence to convert electrical energy in an OLED into light in a highly efficient manner, with the internal quantum efficiencies of such devices approaching 100%.


title: OLED

text: Typically, a polymer such as poly(N-vinylcarbazole) is used as a host material to which an organometallic complex is added as a dopant. Iridium complexes such as Ir(mppy) as of 2004 were a focus of research, although complexes based on other heavy metals such as platinum have also been used.


title: OLED

text: The heavy metal atom at the centre of these complexes exhibits strong spin-orbit coupling, facilitating intersystem crossing between singlet and triplet states. By using these phosphorescent materials, both singlet and triplet excitons will be able to decay radiatively, hence improving the internal quantum efficiency of the device compared to a standard OLED where only the singlet states will contribute to emission of light.


title: OLED

text: Applications of OLEDs in solid state lighting require the achievement of high brightness with good CIE coordinates (for white emission). The use of macromolecular species like polyhedral oligomeric silsesquioxanes (POSS) in conjunction with the use of phosphorescent species such as Ir for printed OLEDs have exhibited brightnesses as high as 10,000cd/m.


title: OLED

text: The bottom-emission organic light-emitting diode (BE-OLED) is the architecture that was used in the early-stage AMOLED displays. It had a transparent anode fabricated on a glass substrate, and a shiny reflective cathode. Light is emitted from the transparent anode direction. To reflect all the light towards the anode direction, a relatively thick metal cathode such as aluminum is used. For the anode, high-transparency indium tin oxide (ITO) was a typical choice to emit as much light as possible. Organic thin-films, including the emissive layer that actually generates the light, are then sandwiched between the ITO anode and the reflective metal cathode. The downside of bottom emission structure is that the light has to travel through the pixel drive circuits such as the thin film transistor (TFT) substrate, and the area from which light can be extracted is limited and the light emission efficiency is reduced.


title: OLED

text: An alternative configuration is to switch the mode of emission. A reflective anode, and a transparent (or more often semi-transparent) cathode are used so that the light emits from the cathode side, and this configuration is called top-emission OLED (TE-OLED). Unlike BEOLEDs where the anode is made of transparent conductive ITO, this time the cathode needs to be transparent, and the ITO material is not an ideal choice for the cathode because of a damage issue due to the sputtering process. Thus, a thin metal film such as pure Ag and the Mg:Ag alloy are used for the semi-transparent cathode due to their high transmittance and high conductivity. In contrast to the bottom emission, light is extracted from the opposite side in top emission without the need of passing through multiple drive circuit layers. Thus, the light generated can be extracted more efficiently.


title: OLED

text: When light waves meet while traveling along the same medium, wave interference occurs. This interference can be constructive or destructive. It is sometimes desirable for several waves of the same frequency to sum up into a wave with higher amplitudes.


title: OLED

text: Since both electrodes are reflective in TEOLED, light reflections can happen within the diode, and they cause more complex interferences than those in BEOLEDs. In addition to the two-beam interference, there exists a multi-resonance interference between two electrodes. Because the structure of TEOLEDs is similar to that of the Fabry-Perot resonator or laser resonator, which contains two parallel mirrors comparable to the two reflective electrodes), this effect is especially strong in TEOLED. This two-beam interference and the Fabry-Perot interferences are the main factors in determining the output spectral intensity of OLED. This optical effect is called the "micro-cavity effect."


title: OLED

text: In the case of OLED, that means the cavity in a TEOLED could be especially designed to enhance the light output intensity and color purity with a narrow band of wavelengths, without consuming more power. In TEOLEDs, the microcavity effect commonly occurs, and when and how to restrain or make use of this effect is indispensable for device design. To match the conditions of constructive interference, different layer thicknesses are applied according to the resonance wavelength of that specific color. The thickness conditions are carefully designed and engineered according to the peak resonance emitting wavelengths of the blue (460 nm), green (530 nm), and red (610 nm) color LEDs. This technology greatly improves the light-emission efficiency of OLEDs, and are able to achieve a wider color gamut due to high color purity.


title: OLED

text: In "white + color filter method," red, green, and blue emissions are obtained from the same white-light LEDs using different color filters. With this method, the OLED materials produce white light which is then filtered to obtain the desired RGB colors. This method eliminated the need to deposit three different organic emissive materials so only one kind of OLED material is used to produce white light. It also eliminated the uneven degradation rate of blue pixels vs. red and green pixels. Disadvantages of this method are low color purity and contrast. Also, the filters absorb most of the light waves emitted, requiring the background white light to be relatively strong to compensate for the drop in brightness, and thus the power consumption for such displays can be higher.


title: OLED

text: Color filters can also be implemented into bottom- and top-emission OLEDs. By adding the corresponding RGB color filters after the semi-transparent cathode, even purer wavelengths of light can be obtained. The use of a microcavity in top-emission OLEDs with color filters also contributes to an increase in the contrast ratio by reducing the reflection of incident ambient light. In a conventional panel, a circular polarizer was installed on the panel surface. While this was provided to prevent the reflection of ambient light, it also reduced the light output. By replacing this polarizing layer with color filters, the light intensity is not affected, and essentially all ambient reflected light can be cut, allowing a better contrast on the display panel. This potentially reduced the need for brighter pixels, and can lower the power consumption.


title: OLED

text: Transparent OLEDs use transparent or semi-transparent contacts on both sides of the device to create displays that can be made to be both top and bottom emitting (transparent). TOLEDs can greatly improve contrast, making it much easier to view displays in bright sunlight. This technology can be used in Head-up displays, smart windows or augmented reality applications.


title: OLED

text: Graded heterojunction OLEDs gradually decrease the ratio of electron holes to electron transporting chemicals. This results in almost double the quantum efficiency of existing OLEDs.


title: OLED

text: Stacked OLEDs use a pixel architecture that stacks the red, green, and blue subpixels on top of one another instead of next to one another, leading to substantial increase in gamut and color depth, and greatly reducing pixel gap. Other display technologies with RGB (and RGBW) pixels mapped next to each other, tend to decrease potential resolution.


title: OLED

text: In contrast to a conventional OLED, in which the anode is placed on the substrate, an Inverted OLED uses a bottom cathode that can be connected to the drain end of an n-channel TFT especially for the low cost amorphous silicon TFT backplane useful in the manufacturing of AMOLED displays.


title: OLED

text: All OLED displays (passive and active matrix) use a driver IC, often mounted using Chip-on-glass (COG), using an Anisotropic conductive film.


title: OLED

text: The most commonly used patterning method for organic light-emitting displays is shadow masking during film deposition, also called the "RGB side-by-side" method or "RGB pixelation" method. Metal sheets with multiple apertures made of low thermal expansion material, such as nickel alloy, are placed between the heated evaporation source and substrate, so that the organic or inorganic material from the evaporation source is deposited only to the desired location on the substrate. Almost all small OLED displays for smartphones have been manufactured using this method.


title: OLED

text: Fine metal masks (FMMs) made by photochemical machining, reminiscent of old CRT shadow masks, are used in this process. The dot density of the mask will determine the pixel density of the finished display. Fine Hybrid Masks (FHMs) are lighter than FFMs, reducing bending caused by the mask's own weight, and are made using an electroforming process.


title: OLED

text: This method requires heating the electroluminescent materials at 300 °C using a thermal method in a high vacuum of 10Pa. An oxygen meter ensures that no oxygen enters the chamber as it could damage (through oxidation) the electroluminescent material, which is in powder form. The mask is aligned with the mother substrate before every use, and it is placed just below the substrate. The substrate and mask assembly are placed at the top of the deposition chamber. Afterwards, the electrode layer is deposited, by subjecting silver and aluminum powder to 1000 °C, using an electron beam. Shadow masks allow for high pixel densities of up to . High pixel densities are


title: OLED

text: Although the shadow-mask patterning method is a mature technology used from the first OLED manufacturing, it causes many issues like dark spot formation due to mask-substrate contact or misalignment of the pattern due to the deformation of shadow mask. Such defect formation can be regarded as trivial when the display size is small, however it causes serious issues when a large display is manufactured, which brings significant production yield loss. To circumvent such issues, white emission devices with 4-sub-pixel color filters (white, red, green and blue) have been used for large televisions. In spite of the light absorption by the color filter, state-of-the-art OLED televisions can reproduce color very well, such as 100% NTSC, and consume little power at the same time. This is done by using an emission spectrum with high human-eye sensitivity, special color filters with a low spectrum overlap, and performance tuning with color statistics into consideration.


title: OLED

text: There are other types of emerging patterning technologies to increase the manufacturabiltiy of OLEDs.


title: OLED

text: Patternable organic light-emitting devices use a light or heat activated electroactive layer. A latent material (PEDOT-TMA) is included in this layer that, upon activation, becomes highly efficient as a hole injection layer. Using this process, light-emitting devices with arbitrary patterns can be prepared.


title: OLED

text: Colour patterning can be accomplished by means of a laser, such as a radiation-induced sublimation transfer (RIST).


title: OLED

text: Organic vapour jet printing (OVJP) uses an inert carrier gas, such as argon or nitrogen, to transport evaporated organic molecules (as in organic vapour phase deposition). The gas is expelled through a micrometre-sized nozzle or nozzle array close to the substrate as it is being translated. This allows printing arbitrary multilayer patterns without the use of solvents.


title: OLED

text: Like ink jet material deposition, inkjet etching (IJE) deposits precise amounts of solvent onto a substrate designed to selectively dissolve the substrate material and induce a structure or pattern. Inkjet etching of polymer layers in OLED's can be used to increase the overall out-coupling efficiency. In OLEDs, light produced from the emissive layers of the OLED is partially transmitted out of the device and partially trapped inside the device by total internal reflection (TIR). This trapped light is wave-guided along the interior of the device until it reaches an edge where it is dissipated by either absorption or emission. Inkjet etching can be used to selectively alter the polymeric layers of OLED structures to decrease overall TIR and increase out-coupling efficiency of the OLED. Compared to a non-etched polymer layer, the structured polymer layer in the OLED structure from the IJE process helps to decrease the TIR of the OLED device. IJE solvents are commonly organic instead of water-based due to their non-acidic nature and ability to effectively dissolve materials at temperatures under the boiling point of water.


title: OLED

text: Transfer-printing is an emerging technology to assemble large numbers of parallel OLED and AMOLED devices efficiently. It takes advantage of standard metal deposition, photolithography, and etching to create alignment marks commonly on glass or other device substrates. Thin polymer adhesive layers are applied to enhance resistance to particles and surface defects. Microscale ICs are transfer-printed onto the adhesive surface and then baked to fully cure adhesive layers. An additional photosensitive polymer layer is applied to the substrate to account for the topography caused by the printed ICs, reintroducing a flat surface. Photolithography and etching removes some polymer layers to uncover conductive pads on the ICs. Afterwards, the anode layer is applied to the device backplane to form the bottom electrode. OLED layers are applied to the anode layer with conventional vapor deposition, and covered with a conductive metal electrode layer. transfer-printing was capable to print onto target substrates up to 500mm × 400mm. This size limit needs to expand for transfer-printing to become a common process for the fabrication of large OLED/AMOLED displays.


title: OLED

text: Experimental OLED displays using conventional photolithography techniques instead of FMMs have been demonstrated, allowing for large substrate sizes (as it eliminates the need for a mask that needs to be as large as the substrate) and good yield control.


title: OLED

text: For a high resolution display like a TV, a thin-film transistor (TFT) backplane is necessary to drive the pixels correctly. As of 2019, low-temperature polycrystalline silicon (LTPS)– TFT is widely used for commercial AMOLED displays. LTPS-TFT has variation of the performance in a display, so various compensation circuits have been reported. Due to the size limitation of the excimer laser used for LTPS, the AMOLED size was limited. To cope with the hurdle related to the panel size, amorphous-silicon/microcrystalline-silicon backplanes have been reported with large display prototype demonstrations. An indium gallium zinc oxide (IGZO) backplane can also be used.


title: OLED

text: The different manufacturing process of OLEDs has several advantages over flat panel displays made with LCD technology.


title: OLED

text: The biggest technical problem for OLEDs is the limited lifetime of the organic materials. One 2008 technical report on an OLED TV panel found that after 1,000hours, the blue luminance degraded by 12%, the red by 7% and the green by 8%. In particular, blue OLEDs at that time had a lifetime of around 14,000hours to half original brightness (five years at eight hours per day) when used for flat-panel displays. This is lower than the typical lifetime of LCD, LED or PDP technology; each rated for about 25,000–40,000hours to half brightness, depending on manufacturer and model. One major challenge for OLED displays is the formation of dark spots due to the ingress of oxygen and moisture, which degrades the organic material over time whether or not the display is powered. In 2016, LG Electronics reported an expected lifetime of 100,000 hours, up from 36,000 hours in 2013. A US Department of Energy paper shows that the expected lifespans of OLED lighting products goes down with increasing brightness, with an expected lifespan of 40,000 hours at 25% brightness, or 10,000 hours at 100% brightness.


title: OLED

text: Degradation occurs because of the accumulation of nonradiative recombination centers and luminescence quenchers in the emissive zone. It is said that the chemical breakdown in the semiconductors occurs in four steps:


title: OLED

text: However, some manufacturers' displays aim to increase the lifespan of OLED displays, pushing their expected life past that of LCD displays by improving light outcoupling, thus achieving the same brightness at a lower drive current. In 2007, experimental OLEDs were created which can sustain 400cd/m of luminance for over 198,000hours for green OLEDs and 62,000hours for blue OLEDs. In 2012, OLED lifetime to half of the initial brightness was improved to 900,000hours for red, 1,450,000hours for yellow and 400,000hours for green at an initial luminance of 1,000cd/m. Proper encapsulation is critical for prolonging an OLED display's lifetime, as the OLED light emitting electroluminescent materials are sensitive to oxygen and moisture. When exposed to moisture or oxygen, the electroluminescent materials in OLEDs degrade as they oxidize, generating black spots and reducing or shrinking the area that emits light, reducing light output. This reduction can occur in a pixel by pixel basis. This can also lead to delamination of the electrode layer, eventually leading to complete panel failure.


title: OLED

text: Degradation occurs three orders of magnitude faster when exposed to moisture than when exposed to oxygen. Encapsulation can be performed by applying an epoxy adhesive with dessicant, by laminating a glass sheet with epoxy glue and dessicant followed by vacuum degassing, or by using Thin-Film Encapsulation (TFE), which is a multi-layer coating of alternating organic and inorganic layers. The organic layers are applied using inkjet printing, and the inorganic layers are applied using Atomic Layer Deposition (ALD). The encapsulation process is carried out under a nitrogen environment, using UV-curable LOCA glue and the electroluminescent and electrode material deposition processes are carried out under a high vacuum. The encapsulation and material deposition processes are carried out by a single machine, after the Thin-film transistors have been applied. The transistors are applied in a process that is the same for LCDs. The electroluminescent materials can also be applied using inkjet printing.


title: OLED

text: The OLED material used to produce blue light degrades much more rapidly than the materials used to produce other colors; in other words, blue light output will decrease relative to the other colors of light. This variation in the differential color output will change the color balance of the display, and is much more noticeable than a uniform decrease in overall luminance. This can be avoided partially by adjusting the color balance, but this may require advanced control circuits and input from a knowledgeable user. More commonly, though, manufacturers optimize the size of the R, G and B subpixels to reduce the current density through the subpixel in order to equalize lifetime at full luminance. For example, a blue subpixel may be 100% larger than the green subpixel. The red subpixel may be 10% larger than the green.


title: OLED

text: Improvements to the efficiency and lifetime of blue OLEDs is vital to the success of OLEDs as replacements for LCD technology. Considerable research has been invested in developing blue OLEDs with high external quantum efficiency, as well as a deeper blue color.


title: OLED

text: Since 2012, research focuses on organic materials exhibiting thermally activated delayed fluorescence (TADF), discovered at Kyushu University OPERA and UC Santa Barbara CPOS. TADF would allow stable and high-efficiency solution processable (meaning that the organic materials are layered in solutions producing thinner layers) blue emitters, with internal quantum efficiencies reaching 100%. Early in 2017, TADF materials based on oxygen-based fully bridged boron-type electron accepttors had achieved huge breakthrough in their proprities. The external quantum efficiency of TADF-OLED for blue and green light had achieved 38%, with thin full-width half-maximum and high color purity. In 2022, Han et al. synthesized a new D-A type luminescent material, TDBA-Cz, and used the m-AC-DBNA synthesized by Meng et al. as a control to investigate the effect of the substitution site of the carbazole unit as an electron donor on the oxygen-bridged triphenylboron electron acceptor unit on the photophysical properties of the overall molecule. It was found that the introduction of two carbazole units into the same benzene ring of the oxygen-bridged triphenylboron electron acceptor unit could effectively suppress the conformational relaxation of the molecule during the radiative transition, resulting in narrow bandwidth blue light emission. In addition, TDBA-Cz is the first reported blue material to achieve both a FWHM down to 45 nm and a maximum EQE of 21.4% in a non-doped TADF-OLED.


title: OLED

text: Blue TADF emitters are expected to market by 2020 and would be used for WOLED displays with phosphorescent color filters, as well as blue OLED displays with ink-printed QD color filters.


title: OLED

text: Water can instantly damage the organic materials of the displays. Therefore, improved sealing processes are important for practical manufacturing. Water damage especially may limit the longevity of more flexible displays.


title: OLED

text: As an emissive display technology, OLEDs rely completely upon converting electricity to light, unlike most LCDs which are to some extent reflective. E-paper leads the way in efficiency with ~ 33% ambient light reflectivity, enabling the display to be used without any internal light source. The metallic cathode in an OLED acts as a mirror, with reflectance approaching 80%, leading to poor readability in bright ambient light such as outdoors. However, with the proper application of a circular polarizer and antireflective coatings, the diffuse reflectance can be reduced to less than 0.1%. With 10,000 fc incident illumination (typical test condition for simulating outdoor illumination), that yields an approximate photopic contrast of 5:1. Advances in OLED technologies, however, enable OLEDs to become actually better than LCDs in bright sunlight. The AMOLED display in the Galaxy S5, for example, was found to outperform all LCD displays on the market in terms of power usage, brightness and reflectance.


title: OLED

text: While an OLED will consume around 40% of the power of an LCD displaying an image that is primarily black, for the majority of images it will consume 60–80% of the power of an LCD. However, an OLED can use more than 300% power to display an image with a white background, such as a document or web site. This can lead to reduced battery life in mobile devices when white backgrounds are used.


title: OLED

text: OLEDs use pulse width modulation to show colour/brightness gradations, so even if the display is at 100% brightness, any pixel that's, for example, 50% grey will be off for 50% of the time, making for a subtle strobe effect. The alternative way to decrease brightness would be to decrease the constant power to the OLEDs, which would result in no screen flicker, but a noticeable change in colour balance, getting worse as brightness decreases.


title: OLED

text: Almost all OLED manufacturers rely on material deposition equipment that is only made by a handful of companies, the most notable one being Canon Tokki, a unit of Canon Inc. Canon Tokki is reported to have a near-monopoly of the giant OLED-manufacturing vacuum machines, notable for their size. Apple has relied solely on Canon Tokki in its bid to introduce its own OLED displays for the iPhones released in 2017. The electroluminescent materials needed for OLEDs are also made by a handful of companies, some of them being Merck, Universal Display Corporation and LG Chem. The machines that apply these materials can operate continuously for 5–6 days, and can process a mother substrate in 5 minutes.


title: OLED

text: OLED technology is used in commercial applications such as displays for mobile phones and portable digital media players, car radios and digital cameras among others, as well as lighting. Such portable display applications favor the high light output of OLEDs for readability in sunlight and their low power drain. Portable displays are also used intermittently, so the lower lifespan of organic displays is less of an issue. Prototypes have been made of flexible and rollable displays which use OLEDs' unique characteristics. Applications in flexible signs and lighting are also being developed. OLED lighting offers several advantages over LED lighting, such as higher quality illumination, more diffuse light source, and panel shapes. Philips Lighting has made OLED lighting samples under the brand name "Lumiblade" available online and Novaled AG based in Dresden, Germany, introduced a line of OLED desk lamps called "Victory" in September, 2011.


title: OLED

text: Nokia introduced OLED mobile phones including the N85 and the N86 8MP, both of which feature an AMOLED display. OLEDs have also been used in most Motorola and Samsung color cell phones, as well as some HTC, LG and Sony Ericsson models. OLED technology can also be found in digital media players such as the Creative ZEN V, the iriver clix, the Zune HD and the Sony Walkman X Series.


title: OLED

text: The Google and HTC Nexus One smartphone includes an AMOLED screen, as does HTC's own Desire and Legend phones. However, due to supply shortages of the Samsung-produced displays, certain HTC models will use Sony's SLCD displays in the future, while the Google and Samsung Nexus S smartphone will use "Super Clear LCD" instead in some countries.


title: OLED

text: OLED displays were used in watches made by Fossil (JR-9465) and Diesel (DZ-7086). Other manufacturers of OLED panels include Anwell Technologies Limited (Hong Kong), AU Optronics (Taiwan), Chimei Innolux Corporation (Taiwan), LG (Korea), and others.


title: OLED

text: DuPont stated in a press release in May 2010, that they can produce a 50-inch OLED TV in two minutes with a new printing technology. If this can be scaled up in terms of manufacturing, then the total cost of OLED TVs would be greatly reduced. DuPont also states that OLED TVs made with this less expensive technology can last up to 15 years if left on for a normal eight-hour day.


title: OLED

text: The use of OLEDs may be subject to patents held by Universal Display Corporation, Eastman Kodak, DuPont, General Electric, Royal Philips Electronics, numerous universities and others. By 2008, thousands of patents associated with OLEDs, came from larger corporations and smaller technology companies.


title: OLED

text: Flexible OLED displays have been used by manufacturers to create curved displays such as the Galaxy S7 Edge but they were not in devices that can be flexed by the users. Samsung demonstrated a roll-out display in 2016.


title: OLED

text: On 31 October 2018, Royole, a Chinese electronics company, unveiled the world's first foldable screen phone featuring a flexible OLED display. On 20 February 2019, Samsung announced the Samsung Galaxy Fold with a foldable OLED display from Samsung Display, its majority-owned subsidiary. At MWC 2019 on 25 February 2019, Huawei announced the Huawei Mate X featuring a foldable OLED display from BOE.


title: OLED

text: The 2010s also saw the wide adoption of "tracking gate-line in pixel" (TGP), which moves the driving circuitry from the borders of the display to in between the display's pixels, allowing for narrow bezels.


title: OLED

text: Textiles incorporating OLEDs are an innovation in the fashion world and pose for a way to integrate lighting to bring inert objects to a whole new level of fashion. The hope is to combine the comfort and low cost properties of textile with the OLEDs properties of illumination and low energy consumption. Although this scenario of illuminated clothing is highly plausible, challenges are still a road block. Some issues include: the lifetime of the OLED, rigidness of flexible foil substrates, and the lack of research in making more fabric like photonic textiles.


title: OLED

text: The number of automakers using OLEDs is still rare and limited to the high-end of the market. For example, the 2010 Lexus RX features an OLED display instead of a thin film transistor (TFT-LCD) display.


title: OLED

text: A Japanese manufacturer Pioneer Electronic Corporation produced the first car stereos with a monochrome OLED display, which was also the world's first OLED product. The Aston Martin DB9 incorporated the world's first automotive OLED display, which was manufactured by Yazaki, followed by the 2004 Jeep Grand Cherokee and the Chevrolet Corvette C6. The 2015 Hyundai Sonata and Kia Soul EV use a 3.5-inch white PMOLED display.


title: OLED

text: By 2004, Samsung Display, a subsidiary of South Korea's largest conglomerate and a former Samsung-NEC joint venture, was the world's largest OLED manufacturer, producing 40% of the OLED displays made in the world, and as of 2010, has a 98% share of the global AMOLED market. The company is leading the world of OLED industry, generating $100.2million out of the total $475million revenues in the global OLED market in 2006. As of 2006, it held more than 600 American patents and more than 2800 international patents, making it the largest owner of AMOLED technology patents.


title: OLED

text: Samsung SDI announced in 2005, the world's largest OLED TV at the time, at . This OLED featured the highest resolution at the time, of 6.22million pixels. In addition, the company adopted active matrix-based technology for its low power consumption and high-resolution qualities. This was exceeded in January 2008, when Samsung showcased the world's largest and thinnest OLED TV at the time, at 31inches (78cm) and 4.3mm.


title: OLED

text: In May 2008, Samsung unveiled an ultra-thin 12.1inch (30cm) laptop OLED display concept, with a 1,280×768 resolution with infinite contrast ratio. According to Woo Jong Lee, Vice President of the Mobile Display Marketing Team at Samsung SDI, the company expected OLED displays to be used in notebook PCs as soon as 2010.


title: OLED

text: In October 2008, Samsung showcased the world's thinnest OLED display, also the first to be "flappable" and bendable. It measures just 0.05mm (thinner than paper), yet a Samsung staff member said that it is "technically possible to make the panel thinner". To achieve this thickness, Samsung etched an OLED panel that uses a normal glass substrate. The drive circuit was formed by low-temperature polysilicon TFTs. Also, low-molecular organic EL materials were employed. The pixel count of the display is 480 × 272. The contrast ratio is 100,000:1, and the luminance is 200cd/m. The colour reproduction range is 100% of the NTSC standard.


title: OLED

text: As of 2020, the world's largest OLED television is an 88-inch with a 8K resolution, frame rate up to 120 fps and cost of 34,676 US Dollars.


title: OLED

text: At the Consumer Electronics Show (CES) in January 2010, Samsung demonstrated a laptop computer with a large, transparent OLED display featuring up to 40% transparency and an animated OLED display in a photo ID card.


title: OLED

text: Samsung's 2010 AMOLED smartphones used their Super AMOLED trademark, with the Samsung Wave S8500 and Samsung i9000 Galaxy S being launched in June 2010. In January 2011, Samsung announced their Super AMOLED Plus displays, which offer several advances over the older Super AMOLED displays: real stripe matrix (50% more sub pixels), thinner form factor, brighter image and an 18% reduction in energy consumption.


title: OLED

text: On 8 January 2013, at CES Samsung unveiled a unique curved 4K Ultra S9 OLED television, which they state provides an "IMAX-like experience" for viewers.


title: OLED

text: On 13 August 2013, Samsung announced availability of a 55-inch curved OLED TV (model KN55S9C) in the US at a price point of $8999.99.


title: OLED

text: On 6 September 2013, Samsung launched its 55-inch curved OLED TV (model KE55S9C) in the United Kingdom with John Lewis.


title: OLED

text: Samsung introduced the "Galaxy Round" smartphone in the Korean market in October 2013. The device features a 1080p screen, measuring , that curves on the vertical axis in a rounded case. The corporation has promoted the following advantages: A new feature called "Round Interaction" that allows users to look at information by tilting the handset on a flat surface with the screen off, and the feel of one continuous transition when the user switches between home screens.


title: OLED

text: Samsung released a new line of OLED TVs in 2022, its first using the technology since 2013. They use panels sourced from Samsung Display; previously, LG was the sole manufacturer of OLED panels for TVs.


title: OLED

text: The Sony CLIÉ PEG-VZ90 was released in 2004, being the first PDA to feature an OLED screen. Other Sony products to feature OLED screens include the MZ-RH1 portable minidisc recorder, released in 2006 and the Walkman X Series.


title: OLED

text: At the 2007, Las Vegas Consumer Electronics Show (CES), Sony showcased a , (resolution 960×540) and , full HD resolution at OLED TV models. Both claimed 1,000,000:1 contrast ratios and total thicknesses (including bezels) of 5mm. In April 2007, Sony announced it would manufacture 1000 OLED TVs per month for market testing purposes. On 1 October 2007, Sony announced that the model XEL-1, was the first commercial OLED TV and it was released in Japan in December 2007.


title: OLED

text: In May 2007, Sony publicly unveiled a video of a flexible OLED screen which is only 0.3 millimeters thick. At the Display 2008 exhibition, Sony demonstrated a 0.2mm thick display with a resolution of 320×200 pixels and a 0.3mm thick display with 960×540 pixels resolution, one-tenth the thickness of the XEL-1.


title: OLED

text: In July 2008, a Japanese government body said it would fund a joint project of leading firms, which is to develop a key technology to produce large, energy-saving organic displays. The project involves one laboratory and 10 companies including Sony Corp. NEDO said the project was aimed at developing a core technology to mass-produce 40inch or larger OLED displays in the late 2010s.


title: OLED

text: In October 2008, Sony published results of research it carried out with the Max Planck Institute over the possibility of mass-market bending displays, which could replace rigid LCDs and plasma screens. Eventually, bendable, see-through displays could be stacked to produce 3D images with much greater contrast ratios and viewing angles than existing products.


title: OLED

text: Sony exhibited a 24.5" (62cm) prototype OLED 3D television during the Consumer Electronics Show in January 2010.


title: OLED

text: In January 2011, Sony announced the PlayStation Vita handheld game console (the successor to the PSP) will feature a 5-inch OLED screen.


title: OLED

text: On 17 February 2011, Sony announced its 25" (63.5cm) OLED Professional Reference Monitor aimed at the Cinema and high end Drama Post Production market.


title: OLED

text: On 25 June 2012, Sony and Panasonic announced a joint venture for creating low cost mass production OLED televisions by 2013.


title: OLED

text: Sony unveiled its first OLED TV since 2008 at CES 2017 called A1E. It revealed two other models in 2018 one at CES 2018 called A8F and other a Master Series TV called A9F. At CES 2019 They unveiled another two models one the A8G and the other another Bravia Series TV called A9G. Then, at CES 2020, they revealed the A8H, which was effectively a A9G in terms of picture quality but with some compromises due to its lower cost. At the same event, they also revealed a 48-inch version of the A9G, making this its smallest OLED TV since the XEL-1.


title: OLED

text: On 9 April 2009, LG acquired Kodak's OLED business and started to utilize white OLED technology. As of 2010, LG Electronics produced one model of OLED television, the 15EL9500 and had announced a OLED 3D television for March 2011. On 26 December 2011, LG officially announced the "world's largest OLED panel" and featured it at CES 2012. In late 2012, LG announces the launch of the 55EM9600 OLED television in Australia.


title: OLED

text: In January 2015, LG Display signed a long-term agreement with Universal Display Corporation for the supply of OLED materials and the right to use their patented OLED emitters.


title: OLED

text: Lumiotec is the first company in the world developing and selling, since January 2011, mass-produced OLED lighting panels with such brightness and long lifetime. Lumiotec is a joint venture of Mitsubishi Heavy Industries, ROHM, Toppan Printing, and Mitsui & Co.


title: OLED

text: On 6 January 2011, Los Angeles-based technology company Recom Group introduced the first small screen consumer application of the OLED at the Consumer Electronics Show in Las Vegas. This was a 2.8" (7cm) OLED display being used as a wearable video name tag. At the Consumer Electronics Show in 2012, Recom Group introduced the world's first video mic flag incorporating three 2.8" (7cm) OLED displays on a standard broadcaster's mic flag. The video mic flag allowed video content and advertising to be shown on a broadcasters standard mic flag.


title: OLED

text: On 6 January 2016, Dell announced the Ultrasharp UP3017Q OLED monitor at the Consumer Electronics Show in Las Vegas. The monitor was announced to feature a 4K UHD OLED panel with a 120Hz refresh rate, 0.1 millisecond response time, and a contrast ratio of 400,000:1. The monitor was set to sell at a price of $4,999 and release in March, 2016, just a few months later. As the end of March rolled around, the monitor was not released to the market and Dell did not speak on reasons for the delay. Reports suggested that Dell canceled the monitor as the company was unhappy with the image quality of the OLED panel, especially the amount of color drift that it displayed when you viewed the monitor from the sides. On 13 April 2017, Dell finally released the UP3017Q OLED monitor to the market at a price of $3,499 ($1,500 less than its original spoken price of $4,999 at CES 2016). In addition to the price drop, the monitor featured a 60Hz refresh rate and a contrast ratio of 1,000,000:1. As of June, 2017, the monitor is no longer available to purchase from Dell's website.


title: OLED

text: Apple began using OLED panels in its watches in 2015 and in its laptops in 2016 with the introduction of an OLED touchbar to the MacBook Pro. In 2017, Apple announced the introduction of their tenth anniversary iPhone X with their own optimized OLED display licensed from Universal Display Corporation. Apple has continued the use of the technology in the iPhone X's successors, such as the iPhone XS and iPhone XS Max, and iPhone 11 Pro and iPhone 11 Pro Max.


title: OLED

text: A third model of Nintendo's Switch, a hybrid gaming system, features an OLED panel in replacement of its current LCD panel. Announced in the summer of 2021, it was released on 8 October 2021.


title: OLED

text: In 2014, Mitsubishi Chemical Corporation (MCC), a subsidiary of Mitsubishi Chemical Holdings, developed an OLED panel with a 30,000-hour life, twice that of conventional OLED panels.


title: OLED

text: The search for efficient OLED materials has been extensively supported by simulation methods; it is possible to calculate important properties computationally, independent of experimental input, making materials development cheaper.


title: OLED

text: On 18 October 2018, Samsung showed of their research roadmap at their 2018 Samsung OLED Forum. This included Fingerprint on Display (FoD), Under Panel Sensor (UPS), Haptic on Display (HoD) and Sound on Display (SoD).


title: OLED

text: Various venders are also researching cameras under OLEDs (Under Display Cameras). According to IHS Markit Huawei has partnered with BOE, Oppo with China Star Optoelectronics Technology (CSOT), Xiaomi with Visionox.


title: OLED

text: In 2020, researchers at the Queensland University of Technology (QUT) proposed using human hair which is a source of carbon and nitrogen to create OLED displays.


title: Wilfried Zaha

text: Dazet Wilfried Armel Zaha (born 10 November 1992) is a professional footballer who plays as a forward for club Crystal Palace and the Ivory Coast national team.


title: Wilfried Zaha

text: Zaha advanced into the Crystal Palace first team from their academy, in 2010. In his first three full seasons at Selhurst Park, he scored 18 goals in all competitions. In January 2013, he was transferred to Manchester United for an initial fee of £10 million (the most expensive Crystal Palace player sold at the time). Zaha remained on loan at Palace until the end of the season, helping them return to the Premier League. After an unsuccessful 2013–14 season with Manchester United (mostly spent on loan at Cardiff City), Zaha returned to Palace in August 2014 on a season-long loan, before rejoining the club on a permanent basis in February 2015. He has since become the club's 12th-highest goal scorer.


title: Wilfried Zaha

text: Born in the Ivory Coast, Zaha grew up in England from age four. He made his debut for the England national team in 2012, appearing in two non-competitive matches (the latter of which came in 2013). After not playing for England for four years, he switched to play for Ivory Coast ahead of the 2017 Africa Cup of Nations.


title: Wilfried Zaha

text: Born in Abidjan, Ivory Coast, Zaha moved with his family – including his eight siblings – to Thornton Heath in the London Borough of Croydon, at age four. He was educated at Whitehorse Manor Junior School, Thornton Heath and Selsdon High School, Selsdon.


title: Wilfried Zaha

text: Zaha was given his Crystal Palace first-team debut at home to Cardiff City on 27 March 2010 by caretaker manager Paul Hart as a substitute for Stern John with 10 minutes remaining in the 2–1 loss. He signed a two-year professional contract with Palace in April.


title: Wilfried Zaha

text: He quickly progressed through the ranks at Palace and became a key member of the first team during the 2010–11 pre-season friendlies. On 7 August 2010, he scored his first senior goal in a 3–2 win over Leicester City. Zaha assisted Kieron Cadogan in the home match against Queens Park Rangers in October and James Vaughan in the away match against Watford in February 2011. On 12 April 2011, he was sent off in the 95th minute against Leicester City for an alleged stamp on Patrick van Aanholt but it was later rescinded. Zaha ended the season playing a total of 44 matches, while scoring 1 goal and having 2 assists in all competitions.


title: Wilfried Zaha

text: Zaha started the 2011–12 season by scoring two goals in a League Cup match on 23 August 2011 at home to Crawley Town. On 30 November, Zaha impressed in Crystal Palace's 2–1 shock win over Manchester United in the League Cup, constantly sneaking through the United defence and in January, attracting interest from Liverpool and Manchester United.


title: Wilfried Zaha

text: In the latter part of the season, manager Dougie Freedman opted to play Zaha as a striker and on 21 April he scored in a 2–2 draw with Reading, in a match that saw Reading secure the Championship title. At the end of the 2011–12 season, Zaha was voted Crystal Palace Young Player of the Year for a second time in a row. During this season, he made 48 appearances while scoring 9 goals and recording 5 assists.


title: Wilfried Zaha

text: Zaha started the 2012–13 season brightly, getting an assist in the League Cup against Exeter City and winning a penalty in the first league match against Watford. Zaha scored his first two goals of the season against Wolverhampton Wanderers on 2 October 2012. He then scored two goals in a match again, four days later, in a 4–3 win over Burnley.


title: Wilfried Zaha

text: On 5 March 2013, Zaha scored his first goal for Crystal Palace since being loaned back from Manchester United, in a 4–2 victory against promotion rivals Hull City. On 13 May 2013, in the second leg of the play-off semi-final against Brighton & Hove Albion, Zaha scored two goals in the second half to put Crystal Palace into the play-off final at Wembley Stadium. In the play-off final on 27 May 2013, Zaha won a penalty that was converted to secure Crystal Palace a Premier League spot for the 2013–14 season.


title: Wilfried Zaha

text: On 25 January 2013, Zaha agreed to join Premier League club Manchester United, and would immediately be loaned back to Crystal Palace for the remainder of the season. Palace tried to delay the transfer and agree the transfer in the summer of 2013, but Football League rules prevented this with the player having to join United and be loaned back to Palace. Zaha passed the medical at Manchester United, signing a five-and-a-half-year contract on 26 January 2013 for a reported £10m rising to £15m with performance-related add-ons.


title: Wilfried Zaha

text: On 11 August 2013, Zaha made his debut for Manchester United in the 2013 FA Community Shield against Wigan Athletic. He was included in the starting line-up and played 61 minutes before being replaced by Antonio Valencia as he won his first major honour in football. He did not play again until 29 October, starting in a 4–0 win over Norwich City in the third round of the League Cup at Old Trafford. His Premier League debut was on 7 December in a 1–0 home loss to Newcastle United, as a substitute for Nani shortly after his team conceded.


title: Wilfried Zaha

text: On 31 January 2014, Zaha completed a loan move to Cardiff City for the remainder of the 2013–14 season after being left out of favour by manager David Moyes.


title: Wilfried Zaha

text: At the end of the season, following Moyes' sacking, Zaha said that he was never given a chance by the Scot. He contrasted his experience with that of Raheem Sterling, another young attacker who was given a chance by Liverpool after a difficult start. He also said that he was upset by false and malicious online rumours about his personal life.


title: Wilfried Zaha

text: On 28 August 2014, Zaha agreed to a season-long loan deal with Crystal Palace. Two days later, in the first match of his loan, he scored a stoppage-time equaliser in a 3–3 draw at Newcastle United. On 2 February 2015, the final day of the winter transfer window, Zaha's move to Palace was made permanent with the signing of a five-and-a-half-year contract for an undisclosed fee, believed to be in the region of £3 million, rising to £6 million with add-ons; Manchester United will also receive a percentage of the fee if Palace sell Zaha in the future.


title: Wilfried Zaha

text: Zaha played regularly for Crystal Palace throughout the season, finishing the season with four goals and two assists as Crystal Palace finished the league in 10th place.


title: Wilfried Zaha

text: Again, Zaha was a regular for Crystal Palace in this season, making 34 appearances, scoring two goals and recording one assist, while Crystal Palace finished in 15th place. He helped Crystal Palace reach the 2016 FA Cup Final, by playing in every match since the third round entry and scoring two goals along the way. Zaha played the whole 120 minutes in the final, but could not help Palace to a victory, as Manchester United won 2–1. Zaha won the Crystal Palace Player of the Year award for the first time.


title: Wilfried Zaha

text: On 26 December 2016, Zaha was denied a penalty in the closing minutes against Watford. Some speculated that Zaha had overplayed the foul or taken a dive. After the match Watford's mascot attempted to rile Zaha up by mimicking a dive in front of him. On 14 May 2017, Zaha scored the opening goal in the third minute of the Crystal Palace Hull city game that simultaneously mathematically secured Crystal Palace's top flight status and relegated Hull City to the Championship. After another outstanding season with The Eagles, Zaha won Crystal Palace's Player of the Year award for the second year running. On 26 May 2017, Zaha signed a new five-year contract with Crystal Palace.


title: Wilfried Zaha

text: On 14 October 2017, Zaha returned to Palace's starting line-up for the first time in two months and scored to open a 2–1 win over Chelsea to give the Eagles their first points of the season. He was Premier League Player of the Month for April 2018 for his four goals and assist while playing up front; on 14 April he scored twice in the first half of a 3–2 win over rivals Brighton & Hove Albion.


title: Wilfried Zaha

text: Despite their poor start, Palace stayed up with a game in hand under new manager Roy Hodgson, with the combination between Zaha and fellow winger Andros Townsend a key factor. He was named their Player of the Year for the third time in a row, a feat only done before by goalkeeper Julián Speroni.


title: Wilfried Zaha

text: In Palace's first game of the new season on 11 August, Zaha scored the second goal of a 2–0 win at Fulham. It was his 23rd Premier League goal for the club, drawing level with Chris Armstrong as their top scorer in the competition's history. Four days he signed a new five-year contract at Crystal Palace. On 26 August, with a consolation goal in a 2–1 loss at Watford, he overtook Armstrong to become Palace's Premier League top scorer.


title: Wilfried Zaha

text: After scoring a winning goal against Huddersfield Town in September 2018, Zaha publicly complained about what he considered to be a lack of appropriate protection by referees against fouls, saying that he would need a broken leg before any action would be taken. Data proved that in the last five years, he was the second most fouled player in the league after Eden Hazard. In October, Zaha was the victim of racist abuse and death threats following a match. Zaha received a red card for dissent against Southampton on 30 January 2019.


title: Wilfried Zaha

text: In June 2019, he was linked with a transfer to Arsenal, who made a £40 million offer for the player, which Crystal Palace rejected as too low. In October, he received racial abuse on social media.`


title: Wilfried Zaha

text: Zaha played in all 38 league matches with Crystal Palace, having a disappointing campaign, scoring only 4 goals, including a long-distance goal against Chelsea.