Question: What area are scientists looking into regarding phosphor LED development?
Answer: higher operation temperatures

Question: What is one method that can raise the efficiency of phosphor-based LEDs?
Answer: adapting better package design

Question: White LEDs can be made by coating what?
Answer: near-ultraviolet (NUV) LEDs

Question: What are near-ultraviolet LEDs coated with to create white LED?
Answer: copper and aluminium-doped zinc sulfide (ZnS:Cu, Al)

Question: What device also works in a similar way as NUV LEDs?
Answer: fluorescent lamps

Question: The method of coating NUVs less efficient than what other LEDs?
Answer: blue

Question: What light can harm human eyes or skin?
Answer: UV light

Question: What is being used to produce white LEDs?
Answer: wafers composed of gallium-nitride-on-silicon

Question: What size are the wafers used to create white LEDs?
Answer: 200-mm

Question: By using silicon wafers, what is being avoided?
Answer: costly sapphire substrate

Question: What needs to be used to reflect light that would otherwise be wasted?
Answer: mirror-like collector

Question: By what year will% of all GaN LEDs be made with gallium-nitride-on-silicon wafers?
Answer: 2020

Question: What nanocrystals possess unique optical properties?
Answer: Quantum dots

Question: Quantum Dot LEDs can do what special skill?
Answer: create almost any color on the CIE diagram

Question: The narrowing of the emission spectrum in Quantum Dot LEDs allows them to do what?
Answer: better color rendering

Question: How many types of schemes are there in Quantum Dot LED excitation?
Answer: two

Question: What is one scheme of Quantum Dot excitation?
Answer: electrical-excitation

Question: What is one material used in electrical-excitation?
Answer: hole-transporting materials

Question: During the electrical-excitation scheme, what moves into the quantum dot layer?
Answer: electrons and holes

Question: A Quantum Dot LED has been used in what?
Answer: near-field scanning optical microscopy (NSOM)

Question: How many lumens can some high-power LEDs emit?
Answer: over a thousand

Question: Up to how many densities have been achieved with LED power?
Answer: 300 W/cm2

Question: Why must High-power LEDs be mounted on a heat sink?
Answer: to allow for heat dissipation

Question: What will happen if the heat from a high-power LED is not removed?
Answer: the device will fail in seconds

Question: What can one high-power LED replace?
Answer: incandescent bulb in a flashlight

Question: What company has developed LEDs that can operate on AC power?
Answer: Seoul Semiconductor

Question: What is the efficacy of an AC powered HP-LED?
Answer: 40 lm/W

Question: When did Seoul Semiconductor release the first high DC voltage LED?
Answer: 2009

Question: What is so good about ac powered HP-LEDs?
Answer: more flexibility

Question: What did Seoul Semiconductor name their ac powered HP-LED?
Answer: Acrich MJT

Question: What type of LEDs are available in seven-segment format?
Answer: Alphanumeric

Question: What is another format that Alphanumeric LEDs are available in?
Answer: dot-matrix

Question: Which alphanumeric LED display can display all letters?
Answer: Starburst

Question: What type of pixels does a dot matrix display use?
Answer: 5x7

Question: What has reduced the popularity of numeric LED displays?
Answer: liquid crystal displays

Question: What makes RGB LEDs different?
Answer: contain their own "smart" control electronics

Question: How are Digital-RGB LED strobe signals connected?
Answer: in a daisy chain

Question: What object sources the data in of the first LED of a digital rgb LED?
Answer: microprocessor

Question: The microprocessor does what in a digital RGB LED?
Answer: control the brightness and color of each LED independently of the others

Question: What is one example of where Digital RGB LED lights are used?
Answer: Christmas

Question: What does an LED filament consist of?
Answer: multiple LED dice

Question: How are LED filaments used?
Answer: a low cost decorative alternative for traditional light bulbs

Question: What type of voltage is needed for LED filaments?
Answer: high

Question: What helps LED filaments remain low cost?
Answer: a simple rectifier

Question: Single die LEDs require what?
Answer: high current converter

Question: How are LEDs similar to other diodes?
Answer: the current is dependent exponentially on the voltage

Question: What is a solution to preventing an LED failure?
Answer: use constant-current power supplies

Question: What can cause a large change in current in LEDs?
Answer: a small change in voltage

Question: What is a constant-voltage source?
Answer: batteries

Question: What feature do most LED fixtures need to have?
Answer: a power converter

Question: How are most LEDs classified?
Answer: Class 1 LED product

Question: What does being a Class 1 LED product mean?
Answer: safe under all conditions of normal use

Question: What type of LED can possibly cause blindness?
Answer: extremely bright LEDs

Question: Which government advocated the banning of Class 2 LEDs?
Answer: French

Question: What class are extremely bright LEDs listed as?
Answer: Class 2

Question: What dangerous metal can LEDs contain?
Answer: arsenic

Question: What substance does fluorescent lamps contain?
Answer: mercury

Question: Which LEDs are considered dangerous by a 2011 study?
Answer: low-intensity red

Question: According to a California study, what harmful metal is in most LEDs?
Answer: lead

Question: What LEDs are considered safer than any other?
Answer: low-intensity yellow LEDs

Question: What type of light is ideal for traffic signals?
Answer: One-color light

Question: In what year were luminescence standards set?
Answer: 1972

Question: What color LEDs are used when night vision is important?
Answer: Red or yellow

Question: What is an example of a night vision needed area?
Answer: astronomy observatories

Question: What is another use for one-color light?
Answer: exit signs

Question: Because of their high output, LED lights are very useful where?
Answer: brake lights for cars

Question: Why are LED lights sought after for various applications?
Answer: their long life

Question: LED brake lights are how many times faster than incandescent ones?
Answer: 0.5 second

Question: What color LEDs are now starting to be used more?
Answer: White

Question: What types of light can LEDs form better than incandescent?
Answer: thinner

Question: Where are infrared LEDs used in everday life?
Answer: theaters

Question: How are LEDs used in theaters?
Answer: to send sound to listeners' receivers

Question: LEDs can send data over what type of cable?
Answer: fiber optic

Question: What type of fiber forms the backbone of the internet?
Answer: very high bandwidth

Question: In what country does one kilowatt-hour of electricity causes 1.34 pounds of CO 2 emission?
Answer: US

Question: How much CO2 emission would a 40-watt light bulb produce after 10 hours?
Answer: 196 pounds

Question: A 6-watt LED left on for 10 hours a day will emit how much CO 2?
Answer: 30 pounds

Question: How much can a building's carbon footprint be reduced by switching to LEDs?
Answer: 85%

Question: LEDs are often used for what type of systems?
Answer: Machine vision

Question: Why are LEDs preferred for machine vision systems?
Answer: so features of interest are easier to process

Question: What can help make LEDs more widely used?
Answer: price drops

Question: What is the most common example of a machine vision system?
Answer: Barcode scanners

Question: Where are some LEDs in machine vision systems found?
Answer: Optical computer mice

Question: Where are LEDs often used?
Answer: free space optics communications

Question: Where are opto-isolators found?
Answer: medical equipment

Question: What is an example of a device that uses free space optic communications?
Answer: remote controls