OLED array substrate and display apparatus

An Organic Light-Emitting Diode (OLED) array substrate and a display apparatus. The OLED array substrate includes a base substrate, a pixel driving circuit and an OLED display element layer which are arranged on the base substrate. The OLED array substrate further includes a solar cell, the solar cell is arranged on a side of the pixel driving circuit which faces an incident ambient light, the solar cell and the pixel driving circuit are insulated from each other, and the solar cell and the OLED display element layer are insulated from each other.

The present application claims priority of the Chinese Patent Application No. 201710624627.8 filed on Jul. 27, 2017, the disclosure of which is incorporated herein by its reference in its entirety as part of the present application.

TECHNICAL FIELD

Embodiments of the present disclosure relate to an Organic Light-Emitting Diode (OLED) array substrate and a display apparatus.

BACKGROUND

An OLED display technology has been successfully commercialized after decades of development, shows huge potential in the high-tech display fields of flexibility, transparence and the like, and meanwhile, is also well developed in the field of illumination.

An OLED display, at the same time of meeting users' demands, should also consider the problem of power endurance, which is very meaningful for both manufacturers and users.

By taking a mobile phone as an example, methods for improving power endurance of the mobile phone are all basically focused on increasing cell capacity and reducing power consumption of electrical devices in the mobile phone. Increasing cell capacity means using a high-capacity cell but the high-capacity cell has a certain potential safety hazard. In addition, as the mobile phone manufacturing technology gradually matures and in order to meet various demands of users, it becomes more and more difficult to reduce the power consumption of the electrical devices of the mobile phone.

SUMMARY

According to embodiments of the disclosure, an Organic Light-Emitting Diode (OLED) array substrate is provided. The OLED array substrate comprises a base substrate, a pixel driving circuit and an OLED display element layer which are arranged on the base substrate. The OLED array substrate further comprises a solar cell, the solar cell is arranged on a side of the pixel driving circuit which faces an incident ambient light, the solar cell and the pixel driving circuit are insulated from each other, and the solar cell and the OLED display element layer are insulated from each other.

For example, the OLED display element layer is arranged on a side of the pixel driving circuit which faces away from the base substrate; and the OLED display element layer is divided into a light-emitting region and a non-light-emitting region, the non-light-emitting region is transparent, and the solar cell is at least arranged between a portion of the OLED display element layer in the non-light-emitting region and the pixel driving circuit.

For example, an insulation layer is arranged between the solar cell and the pixel driving circuit and another insulation layer is arranged between the solar cell and the OLED display element layer.

For example, the OLED display element layer is arranged on a side of the pixel driving circuit which faces away from the base substrate; and the OLED display element layer is divided into a light-emitting region and a non-light-emitting region, and the solar cell is at least arranged on a side of a portion of the OLED display element layer in the non-light-emitting region which faces the incident ambient light.

For example, an insulation layer is arranged between the solar cell and the OLED display element layer.

For example, the solar cell includes a cathode, a first transport layer, an active layer, a second transport layer and an anode which are sequentially arranged; and in the solar cell, a portion arranged on a side of the active layer which faces away from the base substrate is transparent.

For example, the solar cell is a perovskite solar cell or an organic solar cell.

For example, the solar cell includes a plurality of sub solar cells connected with each other in series, and the plurality of sub solar cells connected with each other in series supply power to the OLED array substrate.

For example, the OLED display element layer includes a plurality of OLED display elements, and each of the plurality of OLED display elements includes an anode, a light-emitting functional layer and a cathode which are sequentially arranged along a direction facing away from the base substrate.

For example, the light-emitting functional layer includes: a hole injection layer, a hole transport layer, an electron barrier layer, an light-emitting layer, a hole barrier layer, an electron transport layer and an electron injection layer which are sequentially arranged along a direction facing away from the anode.

For example, each of the plurality of OLED display elements is of a top light-emitting type, and both the cathode and the anode of each of the plurality of OLED display elements include a metal.

For example, the OLED display element layer includes a plurality of OLED display elements, and each of the plurality of OLED display elements includes an anode, a light-emitting functional layer and a cathode which are sequentially arranged along a direction facing away from the base substrate; both the anode and the cathode of the OLED display element are transparent; the solar cell is further arranged between a portion of the OLED display element layer in the light-emitting region and the pixel driving circuit; and a portion of the solar cell between the portion of the OLED display element layer in the light-emitting region and the pixel driving circuit is electrically connected with a portion of the solar cell between the portion of the OLED display element layer in the non-light-emitting region and the pixel driving circuit.

For example, two cell pins are provided in a bonding region of the OLED array substrate, and the two cell pins are respectively connected with the cathode and the anode of the solar cell.

According to the embodiments of the disclosure, a display apparatus comprising the OLED array substrate as described above is provided.

For example, the display apparatus further comprises a power supply circuit, the power supply circuit includes a direct current (DC) converter, and the solar cell is electrically connected with an input end of the DC converter.

For example, the OLED display element layer includes a plurality of OLED display elements; and the plurality of OLED display elements and the pixel driving circuit are electrically connected with an output end of the DC converter.

For example, the display apparatus further comprises a package layer arranged oppositely to the OLED array substrate, the OLED display element layer includes a plurality of OLED display elements, each of the plurality of OLED display elements is a top light-emitting device, and the OLED display apparatus further comprises a polarizer arranged on a side of the package layer which faces away from the OLED array substrate.

DETAILED DESCRIPTION

According to embodiments of the present disclosure, an OLED array substrate is provided. The OLED array substrate includes a base substrate, a pixel driving circuit and an OLED display element layer arranged on the base substrate. The OLED array substrate further includes a solar cell, the solar cell is arranged on a side of the pixel driving circuit which faces an incident ambient light, the solar cell and the pixel driving circuit are insulated from each other, and the solar cell and the OLED display element layer are insulated from each other.

According to the embodiments of the present disclosure, the incident ambient light irradiates the solar cell, and then the solar cell converts light energy into electric energy and supplies the electric energy to the OLED array substrate for compensating electric energy required by an OLED display element for emitting light, so as to benefit energy saving and implement green and environmental protection. The market is enriched and more choices are provided for users.

The incident ambient light, for example, is sunlight, and inFIG. 1(a)andFIG. 1(b), the incident ambient light is shown with vertical arrows.

For example, a region in the pixel driving circuit, where structures such as a thin film transistor and the like are arranged, is not transparent, and thus, by arranging the solar cell on the side of the pixel driving circuit which faces the incident ambient light, it can avoid reduction of the sunlight irradiating the solar cell due to shielding of the structures such as the thin film transistor and the like, or it can avoid arrangement of other light guide structures in the OLED array substrate in order to enable the sunlight originally irradiating the structures such as the thin film transistor and the like to irradiate the solar cell. Therefore, in the embodiments of the present disclosure, by arranging the solar cell on the side of the pixel driving circuit which faces to the incident ambient light, the OLED array substrate has the advantages of high sunlight utilization rate and simple structure.

The OLED array substrate according to the embodiments of the present disclosure will be further described in detail in connection with the drawings.

For example, as shown inFIG. 1(a), the OLED array substrate according to the embodiments of the present disclosure includes a base substrate10, a pixel driving circuit20arranged on the base substrate10and an OLED display element layer50arranged on a side of the pixel driving circuit20which faces away from the base substrate10; the OLED array substrate according to the embodiments of the present disclosure further includes a solar cell40; the OLED display element layer50is divided into a light-emitting region S1and a non-light-emitting region S2, the non-light-emitting region S2is transparent, and the solar cell40is at least arranged between a portion of the OLED display element layer50in the non-light-emitting region S2and the pixel driving circuit20; and the solar cell40and the pixel driving circuit20are insulated from each other, and the solar cell40and the OLED display element layer50are insulated from each other.

For example, the pixel driving circuit20includes a switching transistor, a driving transistor21, a storage capacitor22which is connected with the driving transistor21, power lines (including VDDand VSS), signal lines (including Vgh, Vgland the like), a gate line, a data line and the like (inFIG. 1, for convenience, only the driving transistor21and the storage capacitor22are shown).

For example, the OLED array substrate further include a pixel definition layer60arranged in the transparent non-light-emitting region S2, a supporting layer (not shown in the drawing) for preventing damage to the pixel definition layer60and the like.

For example, the OLED display element layer50includes a plurality of OLED display elements, the light-emitting region S1means a region occupied by one of the OLED display elements, and the non-light-emitting region S2means a region outside the OLED display elements. For example, each OLED display element includes an anode51electrically connected with a drain electrode of the driving transistor21, a light-emitting functional layer52and a cathode, and the light-emitting region S1further means a region occupied by the light-emitting functional layer of one of the OLED display elements.

For example, the anode51, the light-emitting functional layer52and the cathode53are sequentially arranged along a direction facing away from the base substrate10, or are sequentially arranged along a direction close to the base substrate10.

For example, the OLED display element is of a top light-emitting element, or is of a bottom light-emitting element, or is of a double-sided light-emitting element in which both the cathode53and the anode51are transparent. For example, in the case that the OLED display element is of the bottom light-emitting element, the solar cell40is transparent so as to ensure that light from the OLED display element emerges to an external environment.

Exemplarily, by taking a structure that the anode51is closer to the base substrate10than the cathode53as an example, in the case that the anode51is of a total reflection structure and the cathode53is of a semi-reflection structure (i.e., part of the cathode53is of a reflection structure, and part of the cathode53is of a transmission structure), the OLED display element is of the top light-emitting element; and in the case that the anode51is of a total transmission structure and the cathode53is also of a total transmission structure, the OLED display element is of the double-sided light-emitting element.

Herein, in the case that the OLED display element is of the top light-emitting element and the OLED array substrate is applied to an OLED display apparatus, the sunlight irradiates the OLED display element and is reflected by the anode51to emerge from the OLED display apparatus, light intensity of the sunlight is very high, which influences contrast of the OLED display apparatus a lot, particularly the sunlight in high noon is reflected to emerge from the OLED display apparatus and a user nearly cannot see an image displayed by the OLED display apparatus, and thus, the OLED display apparatus for example further include a polarizer120arranged on a side of a package layer110(for example, a package cover plate) which faces away from the OLED array substrate as shown inFIG. 8, so that the sunlight does not emerge from the OLED display apparatus after irradiating the OLED display apparatus, which can avoid influence of the sunlight on the contrast of the OLED display apparatus.

For example, by taking a structure that the anode51is closer to the base substrate10than the cathode53as an example, the cathode53is an anti-reflection electrode so as to reduce or avoid the reflection of the sunlight.

From the above, the OLED display element layer50further includes the transparent non-light-emitting region S2, and the non-light-emitting region S2, for example, means a region in the OLED display element layer50except for the light-emitting region S1. For example, the sunlight passes through the transparent non-light-emitting region S2to irradiate the solar cell40.

For example, the solar cell40and the pixel driving circuit20are insulated from each other and the solar cell40and the OLED display element layer50are insulated from each other mean that: the solar cell40is not in direct contact with the pixel driving circuit20, and the solar cell40is not in direct contact with the OLED display element layer50. For example, insulation layers are respectively arranged between the solar cell40and the pixel driving circuit20and between the solar cell40and the OLED display element layer50so as to avoid an electrical connection of the solar cell40and the OLED display element layer50and an electrical connection of the solar cell40and the pixel driving circuit20. Meanwhile, a parasitic capacitance between the solar cell40and the OLED display element is avoided by regulating a thickness of the insulation layer between the solar cell40and the OLED display element, and exemplarily, the thickness of the insulation layer between the solar cell40and the OLED display element layer50is 3 to 6 μm.

In the embodiments of the present disclosure, a type and a structure of the solar cell40are not limited, as long as a total voltage output by the solar cell40supplies power to the OLED array substrate. For example, the solar cell40is a perovskite solar cell, an organic solar cell and the like.

The solar cell40for example is arranged in different modes as follows. For example, as shown inFIGS. 2(a) to 2(c), the solar cell40only includes one solar cell. The one solar cell is continuously stacked between the entire OLED display element layer50and the entire pixel driving circuit20(inFIG. 2(a), protruding portions in the solar cell respectively are the anode and the cathode of the solar cell). For example, as shown inFIGS. 3(a) to 3(c), the solar cell40include a plurality of sub solar cells, the plurality of sub solar cells are arranged between the entire OLED display element layer50and the entire pixel driving circuit20, the sub solar cells are electrically connected with each other (inFIG. 3(a), the adjacent sub solar cells are electrically connected with each other in series, and portions which are not electrically connected and protrude respectively are the anode and the cathode of the solar cell). For example, the solar cell40is only arranged in a region corresponding to the non-light-emitting region. For example, the solar cell40includes the plurality of sub solar cells, each sub solar cell is only arranged in the region corresponding to the non-light-emitting region, and the sub solar cells are electrically connected with each other in series. It should be noted that the arrangement mode of the solar cell40is not limited to the above modes.

A working principle of the solar cell40is that light energy is converted into electric energy so as to supply power to the OLED array substrate.

The embodiments of the present disclosure provides the OLED array substrate. By at least arranging the solar cell40between the portion of the OLED display element layer50in the non-light-emitting region and the pixel driving circuit20, in the case that the OLED array substrate is applied to the OLED display apparatus, the sunlight passes through the transparent non-light-emitting region of the OLED display element layer50to irradiate the solar cell40, and the solar cell40converts the light energy into the electric energy and supplies the electric energy to the OLED array substrate for compensating electric energy required by the OLED display element for emitting light so as to benefit saving energy and implement green and environment protection. The market is enriched, and more choices are provided for users.

On this basis, in the pixel driving circuit20, the region where the structures such as the thin film transistor and the like are arranged is not transparent, and thus, the solar cell40at least is arranged between the portion of the OLED display element layer50in the non-light-emitting region and the pixel driving circuit20rather than is arranged between the pixel driving circuit20and the base substrate10, which avoids reduction of the sunlight irradiating the solar cell40due to shielding of the structures such as the thin film transistor and the like, or avoids arrangement of other light guide structures in the OLED array apparatus in order to enable the sunlight originally irradiating the structures such as the thin film transistor and the like to irradiate the solar cell40. From the above, the embodiments of the present disclosure have the advantages of high sunlight utilization rate and simple structure.

For example, a planarization layer31formed by an insulation material is arranged between the solar cell40and the pixel driving circuit20, and a planarization layer30formed by an insulation material is arranged between the solar cell40and the OLED display element layer50.

It should be noted that materials of the planarization layers30and31are not limited, as long as the planarization layers are formed by the insulation materials, and for example, the materials of the planarization layers30and31include silicon nitride (SiNx), silicon oxynitride (SiOxNy) and the like.

According to the embodiments of the present disclosure, by arranging the planarization layers formed by the insulation materials between the solar cell40and the pixel driving circuit20and between the solar cell40and the OLED display element layer50, the OLED array substrate not only avoids the electrical connection of the solar cell40and the OLED display element and the electrical connection of the solar cell40and the pixel driving circuit20, but also is beneficial for making each layer of structure in the OLED array substrate more stable.

For example, as shown inFIG. 1(b), the OLED array substrate according to the embodiments of the present disclosure includes the base substrate10, the pixel driving circuit20arranged on the base substrate10, and the OLED display element layer50arranged on the side of the pixel driving circuit which faces away from the base substrate10; the OLED array substrate according to the embodiments of the present disclosure further includes the solar cell40; the OLED display element layer50is divided into the light-emitting region and the non-light-emitting region, and the solar cell40is at least arranged on a side of a portion of the OLED display element layer50in the non-light-emitting region which faces the incident ambient light; and the solar cell40and the pixel driving circuit20are insulated from each other, and the solar cell40and the OLED display element layer50are insulated from each other. For example, as shown inFIG. 1(b), an insulation layer70is arranged between the solar cell40and the OLED display element layer50so that the solar cell40and the OLED display element layer50are insulated from each other; and a plurality of insulation layers, e.g., the insulation layer70, the pixel definition layer60and the planarization layer30, are arranged between the solar cell40and the pixel driving circuit20so that the solar cell40and the pixel driving circuit20are insulated from each other. For example, inFIG. 1(b), the non-light-emitting region of the OLED display element layer50for example is not transparent. It should be noted that other structures inFIG. 1(b)are the same as those inFIG. 1(a), and are not repeated herein.

For example, as shown inFIGS. 2(b), 2(c), 3(b) and 3(c), the solar cell40includes a cathode41, a first transport layer42, an active layer43, a second transport layer44and an anode45which are sequentially arranged; and in the solar cell40, a portion arranged on a side of the active layer43which faces away from the base substrate10is transparent.

For example, the cathode41, the first transport layer42, the active layer43, the second transport layer44and the anode45are sequentially arranged along a direction facing away from the base substrate as shown inFIGS. 2(b) and 3(b), or are sequentially arranged along a direction close to the base substrate10as shown inFIGS. 2(c) and 3(c), which is not limited herein; however, it should be noted that no matter in which mode the cathode41, the first transport layer42, the active layer43, the second transport layer44and the anode45are arranged, it at least should be ensured that in the solar cell40, the portion arranged on the side of the active layer43, which faces away from the base substrate10, is transparent so as to enable the sunlight to irradiate the active layer43.

Exemplarily, the cathode41, the first transport layer42, the active layer43, the second transport layer44and the anode45are sequentially arranged along the direction facing away from the base substrate10, it at least should be ensured that the anode45and the second transport layer44are transparent; and the cathode41, the first transport layer42, the active layer43, the second transport layer44and the anode45are sequentially arranged along the direction close to the base substrate10, it at least should be ensured that the cathode41and the first transport layer42are transparent.

For example, a material of the transparent anode45is a transparent conductive material such as Indium Tin Oxide (ITO) and the like; and a material of the transparent cathode41is a mixture of SrVO3and CaVO3, or a metal which has a very small thickness so as to transmit light, e.g., Al.

In consideration that a case of adopting the metal as the material of the cathode41is relatively matured and transmittance of the metal is smaller than that of the transparent conductive material such as ITO and the like, preferably, as shown inFIGS. 2(b) and 3(b), the cathode41, the first transport layer42, the active layer43, the second transport layer44and the anode45are sequentially arranged along the direction facing away from the base substrate10.

For example, by taking a case that the cathode41, the first transport layer42, the active layer43, the second transport layer44and the anode45are sequentially arranged along the direction facing away from the base substrate10as an example, the sunlight passes through the anode45and the second transport layer44to irradiate the active layer43, the active layer43converts light energy into electric energy and then the electric energy is output through the anode45and the cathode41so as to supply power to the OLED array substrate. The first transport layer42and the second transport layer44take effects of optimizing an energy level structure and improving energy conversion efficiency.

Those skilled in the art should know that for different types of solar cells40, materials of the first transport layers42, the active layers43and the second transport layers44are different.

In the embodiments of the present disclosure, the solar cell40includes the cathode41, the first transport layer42, the active layer43, the second transport layer44and the anode45which are sequentially arranged for supplying power to the OLED array substrate.

For example, the solar cell40is a perovskite solar cell (PSC) or an organic solar cell (OSC) (which is also called as organic photovoltaics (OPV). For example, the solar cell40includes the plurality of sub solar cells connected with each other in series, and the plurality of sub solar cells connected with each other in series supply power to the OLED array substrate.

For example, a voltage output by one sub PSC or a voltage output by one sub OSC approximates to 1V, but a voltage for the OLED array substrate to enable each OLED display element to emit light is greater than 1V; and thus, according to the embodiments of the present disclosure, the PSC or the OSC is formed by the plurality of sub solar cells connected with each other in series so as to supply power to the OLED array substrate.

For example, in the case that the solar cell40is the PSC, the material of the active layer43is perovskite which for example is formed by a complex of PbCl2and CH3NH3I, the first transport layer42is also called as an electron transport layer (ETL), the material of the first transport layer42for example is [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), the second transport layer44is also called as a hole transport layer (HTL), and the material of the second transport layer44for example is MoOx.

For example, PbCl2is formed by adopting an evaporation (EV) process, and CH3NH3I only needs to be heated; PCBM is formed by adopting the EV process; and MoOxis formed by adopting a sputtering process.

For example, in the case that the solar cell40is the organic solar cell, the material of the active layer43is poly [[2,6′-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,3-b]dithiophene] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]]:[6,6]-phenyl C71butyric acid methyl ester (PTB7-TH:PC71BM), the first transport layer42is also called as a cathode interface modification layer, the material of the first transport layer42is poly [(9,9-bis(3′-(N,N-d methylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN), the second transport layer44is also called as the HTL, and the material of the second transport layer44is MoOx.

For example, both PTB7-TH:PC71BM and PFN are formed by adopting an inkjet process.

For example, in the case that the material of the cathode41is Al and the material of the anode44is ITO, as shown inFIG. 4, it can be seen that in a visible light range, monochromatic incident photon-to-electron conversion efficiency (IPCE) of the PSC prepared by adopting the above materials reaches about 80%; and as shown inFIG. 5, it can be seen that in the visible light range, external quantum efficiency (EQE) of the OSC prepared by adopting the above materials reaches about 80%. It also means that the perovskite cell and the OSC have good light absorption capacity, and about 80% of sunlight are absorbed and utilized so as to show excellent absorption capacity.

The EQE means: a ratio of the number of charge carriers generated in the solar cell40to the number of photons with a certain energy, which are incident to the surface of the solar cell from the outside.

In the embodiments of the present disclosure, compared with other types of solar cells40, the PSC or the OSC is adopted on the OLED array substrate so that, in the case that the OLED array substrate is applied to the OLED display apparatus, heat generation of the OLED display apparatus is reduced, and user's experience is improved.

For example, as shown inFIG. 1, the OLED display element layer50includes a plurality of OLED display elements, and each OLED display element includes an anode51, a light-emitting functional layer52and a cathode53which are sequentially arranged along a direction facing away from the base substrate10.

For example, the light-emitting functional layer52at least includes a hole transport layer (HTL) arranged close to the anode51, an electron transport layer (ETL) arranged close to the cathode53, and an light emitting layer (EL) arranged between the HTL and the ETL.

In the embodiments of the present disclosure, a material of the anode51, e.g., ITO, needs to have a high work function; in the case that a pattern of the anode51is formed by using ITO, the sputtering process is generally adopted and the sputtering process has adverse effects on the organic material; a material of the cathode53, e.g., metals of Ag, Al, Ca, In, Li, Mg and the like, needs to have a low work function, the evaporation process is generally adopted and the evaporation process has no adverse effects on the organic material; the light-emitting functional layer52includes the organic material, and thus, by arranging the anode51, the light-emitting functional layer52and the cathode53along the direction facing away from the base substrate10, the adverse effects on the light-emitting functional layer52due to formation of the anode51is avoided.

For example, as shown inFIG. 6, the light-emitting functional layer52includes: a hole injection Layer (HIL)521, the HTL522, an electron barrier layer (EBL)523, the light emitting layer (EML)524, a hole barrier layer (HBL)525, the ETL526and an electron injection layer (EIL)527which are sequentially arranged along a direction facing away from the anode51.

In the embodiments of the present disclosure, the HIL521, the HBL523, the HBL525and the EIL527optimize the energy level structure and improve luminous efficiency.

For example, the OLED display element is of the top light-emitting element; and both the cathode53and the anode of the OLED display element include a metal.

For example, in the case that the OLED display element of the top light-emitting element is applied to the OLED display apparatus, the OLED display apparatus further includes the polarizer120arranged on the side of the package layer110(for example, the package cover plate) as shown inFIG. 8, which faces away from the OLED array substrate.

For example, as shown inFIG. 7(a), in consideration that the metal is easy to oxidize upon in contact with moisture, the anode51is of a three-layer structure and includes two transparent conductive layers and a metal layer arranged between the two transparent conductive layers, the transparent conductive layer on the side close to the base substrate10takes an effect of preventing the metal layer from being oxidized due to direct contact with moisture. Exemplarily, a material of two transparent conductive layer is ITO, and a material of the metal layer is Ag.

For example, as shown inFIG. 7(b), the anode51is of a two-layer structure and includes a metal layer and a transparent conductive layer arranged on a side of the metal layer close to the base substrate10. Exemplarily, a material of the transparent conductive layer is ITO, and a material of the metal layer includes Ag or Al.

It should be noted that although the cathode53includes the metal, in a case of not influencing normal working of the cathode53, a thickness of the cathode53needs to be as small as possible so as to enable light to transmit.

Those skilled in the art should know that in the case that both the cathode53and the anode51include the metal, part of light emitted by the light-emitting region is reflected to and from between the cathode53and the anode51so as to form a microcavity structure between the cathode53and the anode51, and meanwhile, light with a specific wavelength is strengthened and emerges with a specific angle by regulating a thickness between the cathode53and the anode51. For example, the light emerges with a direction perpendicular to the base substrate10by regulating the thickness between the cathode53and the anode51, and thus, luminous efficiency of the light emerging along the direction perpendicular to the base substrate10is improved, which is consistent with the user's habit of viewing the display vertically, and meanwhile, chroma of single-color light is also improved.

For example, inFIG. 1(a), the solar cell40is arranged between the OLED display element layer50and the pixel driving circuit20; the cathode41of the solar cell40generally adopts a metal material, and in this case, even though the thickness of the cathode41of the solar cell40is set as small as possible so as to enable light to transmit, transmittance of the cathode41of the solar cell40is still relatively low. Thus, according to the embodiments of the present disclosure, by adopting the OLED display element of the top light-emitting element, light for display is prevented from passing through the solar cell40to reduce light transmittance.

By taking the OLED display element of the top light-emitting element as an example, compensation efficiency of the PSC and compensation efficiency of the OSC are respectively estimated below.

In a first step, if transmittance of the polarizer120is 45% and transmittance of the package layer110is 90.84%, total transmittance of the polarizer120and the package layer110is 45%×90.84%≈40.88%; and if the maximum displayable brightness of the OLED display apparatus is 350 nit, brightness without coverage of the polarizer120and the package layer110is 350÷40.88%≈856.2 nit, wherein 1 nit=1 cd/m2(candela per square meter).

In a second step, if a user adopts half of the maximum displayable brightness of the OLED display apparatus to view, luminous brightness without coverage of the polarizer120and the package layer110is 856.2÷2=428.1 nit, and according to color coordinates of R (0.663, 0.336), G (0.244, 0.704), B (0.141, 0.052) and W (0.299, 0.316), brightness decomposition is carried out to obtain single-color brightness, i.e., R is 110.7 nit, G is 285.1 nit and B is 32.3 nit, wherein R represents red light, G represents green light, B represents blue light, and W represents white light.

In a third step, if brightness of single-color light and luminous efficiency of the single-color light are known, a current density of the single-color light is obtained according to a formula that

brightnessluminous⁢⁢efficiency=current⁢⁢density;
if luminous efficiency of the red light is 50 cd/A (candela per ampere), luminous efficiency of the green light is 120 cd/A and luminous efficiency of the blue light is 6.5 cd/A, the current density of the red light is

110.750≈2.21⁢⁢A⁢/⁢m2
(ampere per square meter), and similarly, the current density of the green light approximately is 2.38 A/m2, and the current density of the blue light approximately is 4.96 A/m2; on this basis, if an area of a display region of the OLED display apparatus is known, a current required by the single-color light is obtained according to a formula that current density×area=current, if a 5.7 inch (71×125 mm) OLED display apparatus is adopted, the current required by the red light is 2.21×0.008875≈0.02 A (ampere), and similarly, a current required by the green light approximately is 0.021 A, and the current required by the blue light approximately is 0.044 A; and if it is known that a voltage is 7.6V (volt), according to a formula that voltage×total current=total power consumption, total power consumption total power consumption=7.6×(0.02+0.021+0.044)=0.64 W(watt) of the OLED display apparatus is obtained, i.e., if the user adopts half of the maximum displayable brightness of the OLED display apparatus to view, the power consumption is 0.64 W.

In a fourth step, if an area ratio of the light-emitting region in the OLED display element layer50is 19%, an area ratio of the transparent non-light-emitting region is 81%, and the sunlight needs to pass through the package layer110and the polarizer120to irradiate the solar cell40, and thus, a utilization rate of the sunlight is 81%×4.088%≈33.1%.

In a fifth step, if the PSC is adopted and it is known that the IPCE of the PSC is 15% and sunlight power in unit area is 100 mW/cm2under the condition of AM1.5 (i.e., the sunlight when a zenith angle is 48 degrees), power consumption which is compensated to the OLED display apparatus by the PSC is 100 mW/cm2×33.1%×15%×0.008875 m2≈0.44 W, so that it is calculated that the compensation efficiency of the PSC is 0.44÷0.64=68.75%; and if the OSC is adopted and it is known that the IPCE of the OSC is 10% and sunlight power in unit area is 100 mW/cm2under the condition of AM1.5, power consumption which is compensated to the OLED display apparatus by the OSC is 100 mW/cm2×33.1%×10%×0.008875 m2≈0.29 W, so that it is calculated that the compensation efficiency of the PSC is 0.29÷0.64≈45.31%.

For example, both the anode51and the cathode53of the OLED display element enable light to transmit. For the structure shown inFIG. 1(a), the solar cell40is further arranged between the portion of the OLED display element layer50in the light-emitting region and the pixel driving circuit20, and a portion of the solar cell40between the portion of the OLED display element layer50in the light-emitting region and the pixel driving circuit20is electrically connected with a portion of the solar cell40between the portion of the OLED display element layer50in the non-light-emitting region and the pixel driving circuit20.

For example, the material of the anode51is a transparent conductive material such as ITO and the like, and the material of the cathode53includes a metal.

It should be noted that although the cathode53includes the metal, in the case of not influencing normal working of the cathode53, the thickness of the cathode53needs to be as small as possible so as to enable light to transmit.

In the embodiments of the present disclosure, by adopting the OLED display element of which both the anode51and the cathode53enable light to transmit, compared to the OLED display element with the top light-emitting structure and the OLED display element with the bottom light-emitting structure, the light energy of the sunlight which irradiates the solar cell40is the maximum, so that the electric energy obtained by the solar cell40converting the light energy is the maximum.

Herein, by taking the OLED display element of which both the anode51and the cathode53enable light to transmit as an example, the compensation efficiency of the PSC and the compensation efficiency of the OSC are respectively estimated.

In a first step, if transmittance of the package layer110is 90.84% and the maximum displayable brightness of the OLED display apparatus is 350 nit, the brightness without coverage of the package layer110is 350÷90.84%≈385.3 nit.

In a second step, if the user adopts half of the maximum displayable brightness of the OLED display apparatus to view, luminous brightness without coverage of the package layer110is 385.3÷2=192.65 nit, and according to color coordinates of R (0.663, 0.336), G (0.244, 0.704), B (0.141, 0.052) and W (0.299, 0.316), brightness decomposition is carried out to obtain single-color brightness, i.e., R is 49.8 nit, G is 128.3 nit and B is 14.5 nit.

In a third step, when brightness of single-color light and luminous efficiency of the single-color light are known, a current density of the single-color light is obtained according to a formula that

brightnessluminous⁢⁢efficiency=current⁢⁢density,
if luminous efficiency of the red light is 50 cd/A (candela per ampere), luminous efficiency of the green light is 120 cd/A and luminous efficiency of the blue light is 6.5 cd/A, the current density of the red light is

49.850≈0.996/m2,
and similarly, the current density of the green light approximately is 1.07 A/m2, and the current density of the blue light approximately is 2.236 A/m2; on this basis, if an area of a display region of the OLED display apparatus is known, a current required by the single-color light is obtained according to a formula that current density×area=current, if a 5.7 inch (71×125 mm) OLED display apparatus is adopted, the current required by the red light is 0.996×0.008875=≈0.009 A, and similarly, the current required by the green light approximately is 0.009 A, and the current required by the blue light approximately is 0.02 A; and if it is known that a voltage is 7.6V, according to a formula that voltage×total current=total power consumption, total power consumption total power consumption=7.6×(0.009+0.009+0.02)=0.29 W of the OLED display apparatus is obtained, i.e., if the user adopts half of the maximum displayable brightness of the OLED display apparatus to view, the power consumption is 0.29 W.

In a fourth step, if an area ratio of the light-emitting region in the OLED display element layer50is 19%, an area ratio of the transparent non-light-emitting region is 81%, the transmittance of the light-emitting region is 80%, and the sunlight needs to pass through the package layer110to irradiate the solar cell40, and thus, a utilization rate of the sunlight is 81%×90.84%+19%×90.84%×80%≈87.39%.

In a fifth step, if the PSC is adopted and it is known that the IPCE of the PSC is 15% and sunlight power in unit area is 100 mW/cm2under the condition of AM1.5, power consumption which is compensated to the OLED display apparatus by the PSC is 100 mW/cm2×87.39%×15%×0.008875 m2≈1.16 W, so that it is calculated that the compensation efficiency of the PSC is 1.16÷0.29=400%; and if the OSC is adopted and it is known that the IPCE of the OSC is 10% and sunlight power in unit area is 100 mW/cm2under the condition of AM1.5, power consumption which is compensated to the OLED display apparatus by the OSC is 100 mW/cm2×87.39%×10%×0.008875 m2≈0.78 W, so that it is calculated that the compensation efficiency of the PSC is 0.78÷0.29≈268.97%.

On this basis, in the case that the OLED display apparatus emits light, the light emitted by the light-emitting region also irradiates the solar cell40, and similarly, the solar cell40converts such part of light energy into electric energy for compensating power consumption.

From the above, for collocation of the PSC and the OLED display element with the top light-emitting type, collocation of the OSC and the OLED display element with the top light-emitting type, collocation of the PSC and the OLED display element of which both the anode51and the cathode53enable light to transmit and collocation of the OSC and the OLED display element of which both the anode51and the cathode53enable light to transmit, by comparing the compensation efficiency of the above different collocations, it can be seen that the compensation efficiency of the collocation of the PSC and the OLED display element of which both the anode51and the cathode53enable light to transmit is the highest.

For example, two cell pins101are arranged in a bonding region of the OLED array substrate, and the two cell pins101are respectively connected with the cathode41and the anode45of the solar cell40.

FIG. 1(c)is a planar schematic diagram of the OLED array substrate provided by the embodiments of the present disclosure. As shown inFIG. 1(c), the OLED array substrate according to the embodiments of the disclosure comprises an active region AA and a peripheral region PA surrounding the active region AA, the bonding region is provided in the peripheral region PA, and the two cell pins101are arranged in the bonding region. For example, the components such as the pixel driving circuit20, the OLED display element layer50and the solar cell40are provided in the active region AA.

In the embodiments of the present disclosure, the two cell pins101are arranged in the bonding region of the OLED array substrate and are respectively connected with the cathode41and the anode45of the solar cell40, so that a lead for connecting the solar cell40with a power supply circuit in the OLED display apparatus become more firm.

The embodiments of the present disclosure further provide a display apparatus. As shown inFIG. 8, the display apparatus comprises an OLED array substrate100, which is the OLED array substrate according to any one of the above-mentioned embodiments. The display apparatus for example further comprises a package layer110(such as a package cover plate) covering the OLED array substrate100to protect the OLED array substrate100. For example, the display apparatus further comprises a polarizer120provided on a side of the package layer110facing away from the OLED array substrate100. For example, the display apparatus according to the embodiments of the present disclosure further includes a power supply circuit, the power supply circuit includes a direct current (DC) converter, and the solar cell is electrically connected with an input end of the DC converter. For example, the cathode41and the anode45of the solar cell40are electrically connected with the input end of the DC converter.

For example, the OLED display element and the pixel driving circuit are electrically connected with an output end of the DC converter. For example, the cathode53of the OLED display element and the pixel driving circuit20connected with the anode51of the OLED display element are electrically connected with the output end of the DC converter. The OLED display apparatus further includes other power supply devices, e.g., a lithium battery, which are electrically connected with the input end of the DC converter.

For example, the cathode41and the anode45of the solar cell40are electrically connected with the two cell pins101in the bonding region on the OLED array substrate, and then the two cell pills101are electrically connected with the input end of the DC converter.

For example, the DC converter is a DC/DC (DC converter, or DC transformer) for converting a fixed DC voltage into a variable DC voltage, and moreover, the DC/DC, according to the compensation efficiency of the solar cell40, selects to only utilize the solar cell40to supply power, or only utilize other power supply devices in the OLED display apparatus to supply power, or simultaneously utilize the solar cell40and other power supply devices in the OLED display apparatus to supply power.

According to embodiments of the present disclosure, the display apparatus which includes the OLED array substrate is provided. The OLED array substrate includes the pixel driving circuit and the OLED display element layer. The OLED array substrate further includes the solar cell, the solar cell is arranged on the side of the pixel driving circuit which faces the incident ambient light. The incident ambient light irradiates the solar cell, and then the solar cell converts light energy into electric energy and supplies the electric energy to the OLED array substrate for compensating electric energy required by the OLED display element for emitting light, so as to benefit energy saving and implement green and environmental protection. The market is enriched and more choices are provided for users.

For example, the region in the pixel driving circuit, where structures such as the thin film transistor and the like are arranged, is not transparent, and thus, by arranging the solar cell on the side of the pixel driving circuit which faces the incident ambient light, it can avoid reduction of the sunlight irradiating the solar cell due to shielding of the structures such as the thin film transistor and the like, or it can avoid arrangement of other light guide structures in the OLED array substrate in order to enable the sunlight originally irradiating the structures such as the thin film transistor and the like to irradiate the solar cell. Therefore, in the embodiments of the present disclosure, by arranging the solar cell on the side of the pixel driving circuit which faces to the incident ambient light, the OLED array substrate has the advantages of high sunlight utilization rate and simple structure.

The foregoing embodiments merely are exemplary embodiments of the disclosure, and not intended to define the scope of the disclosure, and the scope of the disclosure is determined by the appended claims.