COMPOSITE INTERFACE TRANSPORT MATERIAL-BASED PEROVSKITE PHOTOVOLTAIC, LIGHT EMISSION AND LIGHT DETECTION MULTI-FUNCTIONAL DEVICE AND PREPARATION METHOD THEREFOR

Abstract

A composite interface transport material-based perovskite photovoltaic, light emission and light detection multi-functional device and a preparation method therefor. The multi-functional device comprises a transparent conductive glass, a composite electron transport layer, a perovskite active layer, a composite hole transport layer and a metal electrode layer which are sequentially arranged in a stacked manner from bottom to top. The work functions of the interface transport layers are adjusted by means of the multi-element interface transport materials, so that the work functions of the electron transport layer and the hole transport layer are respectively levelled with conduction band and valence band positions of the perovskite active layer. According to experiment result comparisons, the photoelectric conversion efficiency and the luminous efficiency of the perovskite multi-functional device, after energy band regulation, are significantly increased.

Claims

1. A composite interface transport material-based perovskite photovoltaic, light emission and light detection multi-functional device, the light detection multi-functional device comprises a transparent conductive electrode layer, a composite electron transport layer, a perovskite active layer, a composite hole transport layer and a metal electrode layer which are sequentially arranged in a stacked manner from bottom to top.

2. The light detection multi-functional device of claim 1, wherein the transparent conductive electrode layer is an ITO or FTO transparent conductive glass; the metal electrode layer is gold, silver, copper or aluminum.

3. The light detection multi-functional device of claim 1, wherein the composite electron transport layer has a thickness of 5-120 nm; the composite electron transport layer is made of an amino-graphene quantum dot, and further comprises stannic oxide or titanium dioxide prepared from a chlorine salt, and a mass ratio of the chlorine salt to the amino-graphene quantum dot ranges from 10:1 to 1000:1.

4. The light detection multi-functional device of claim 1, wherein the perovskite active layer is one or more of CH.sub.3NH.sub.3PbX.sub.3, NH.sub.2CH.sub.2NH.sub.3PbX.sub.3 or CsPbX.sub.3, and X is I or Br; the perovskite active layer has a thickness of 50-600 nm.

5. The light detection multi-functional device of claim 1, wherein the composite hole transport layer has a thickness of 20-200 nm, and the composite hole transport layer is spiro-OMeTAD:FN—Br composited by spiro-OMeTAD and FN—Br, and a mass ratio of spiro-OMeTAD to FN—Br is 10-1000:1.

6. The light detection multi-functional device of claim 5, wherein in the composite hole transport layer material, FN—Br is replaced by TFB or F8BT having a work function greater than 5.4 eV.

7. A preparation method of the light detection multi-functional device of claim 1, comprising the following steps: (1) Cleaning of the transparent conductive glass performing ultrasonic cleaning on a conductive glass, drying the conductive glass with nitrogen or compressed air, then performing surface cleaning treatment by an ultraviolet light to remove organic matters and enhance film-forming property; (2) Preparation of the composite electron transport layer Preparing a precursor solution from stannous chloride, stannic chloride or titanium tetrachloride, then adding amino-graphene quantum dots for mixing, and spin coating a mixed solution on the transparent conductive glass, then performing heat treatment, and performing ultraviolet ozonation treatment after cooling, where a dangling bond formed by the ozonation treatment enhances the subsequent film-forming property; (3) Preparation of the perovskite active layer Spin coating a perovskite precursor solution on the composite electron transport layer, and dropwise adding an antisolvent for continuous spin coating when the solvent is wet, and performing heat treatment on the spin coated perovskite film; (4) Preparation of the composite hole transport layer Spin coating a mixed solution of spiro-OMeTAD and FN—Br on a surface of the perovskite active layer; (5) Preparation of a metal electrode Evaporating gold or silver on the composite hole transport layer under vacuum conditions to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

8. The preparation method of claim 7, wherein a solvent in the precursor solution is ethanol, and stannous chloride or stannic chloride has a concentration of 0.1%-10 wt %, the amino-graphene quantum dot has a concentration of 0.01-1 wt %; and in the step (2), heat treatment refers to heating for 0.5-2 h at 180-270° C., and the ultraviolet ozonation treatment is performed for 5-15 min.

9. The preparation method of claim 7, wherein the mixed solution of spiro-OMeTAD and FN—Br is obtained by dissolving spiro-OMeTAD and FN—Br powder into chlorobenzene, and spiro-OMeTAD has a concentration of 1-10 wt %, and FN—Br has a concentration of 0.01-1 wt %.

10. A preparation method of the light detection multi-functional device of claim 2, comprising the following steps: (1) Cleaning of the transparent conductive glass performing ultrasonic cleaning on a conductive glass, drying the conductive glass with nitrogen or compressed air, then performing surface cleaning treatment by an ultraviolet light to remove organic matters and enhance film-forming property; (2) Preparation of the composite electron transport layer Preparing a precursor solution from stannous chloride, stannic chloride or titanium tetrachloride, then adding amino-graphene quantum dots for mixing, and spin coating a mixed solution on the transparent conductive glass, then performing heat treatment, and performing ultraviolet ozonation treatment after cooling, where a dangling bond formed by the ozonation treatment may enhance the subsequent film-forming property; (3) Preparation of the perovskite active layer Spin coating a perovskite precursor solution on the composite electron transport layer, and dropwise adding an antisolvent for continuous spin coating when the solvent is wet, and performing heat treatment on the spin coated perovskite film; (4) Preparation of the composite hole transport layer Spin coating a mixed solution of spiro-OMeTAD and FN—Br on a surface of the perovskite active layer; (5) Preparation of a metal electrode Evaporating gold or silver on the composite hole transport layer under vacuum conditions to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

11. A preparation method of the light detection multi-functional device of claim 3, comprising the following steps: (1) Cleaning of the transparent conductive glass performing ultrasonic cleaning on a conductive glass, drying the conductive glass with nitrogen or compressed air, then performing surface cleaning treatment by an ultraviolet light to remove organic matters and enhance film-forming property; (2) Preparation of the composite electron transport layer Preparing a precursor solution from stannous chloride, stannic chloride or titanium tetrachloride, then adding amino-graphene quantum dots for mixing, and spin coating a mixed solution on the transparent conductive glass, then performing heat treatment, and performing ultraviolet ozonation treatment after cooling, where a dangling bond formed by the ozonation treatment may enhance the subsequent film-forming property; (3) Preparation of the perovskite active layer Spin coating a perovskite precursor solution on the composite electron transport layer, and dropwise adding an antisolvent for continuous spin coating when the solvent is wet, and performing heat treatment on the spin coated perovskite film; (4) Preparation of the composite hole transport layer Spin coating a mixed solution of spiro-OMeTAD and FN—Br on a surface of the perovskite active layer; (5) Preparation of a metal electrode Evaporating gold or silver on the composite hole transport layer under vacuum conditions to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

12. A preparation method of the light detection multi-functional device of claim 4, comprising the following steps: (1) Cleaning of the transparent conductive glass performing ultrasonic cleaning on a conductive glass, drying the conductive glass with nitrogen or compressed air, then performing surface cleaning treatment by an ultraviolet light to remove organic matters and enhance film-forming property; (2) Preparation of the composite electron transport layer Preparing a precursor solution from stannous chloride, stannic chloride or titanium tetrachloride, then adding amino-graphene quantum dots for mixing, and spin coating a mixed solution on the transparent conductive glass, then performing heat treatment, and performing ultraviolet ozonation treatment after cooling, where a dangling bond formed by the ozonation treatment may enhance the subsequent film-forming property; (3) Preparation of the perovskite active layer Spin coating a perovskite precursor solution on the composite electron transport layer, and dropwise adding an antisolvent for continuous spin coating when the solvent is wet, and performing heat treatment on the spin coated perovskite film; (4) Preparation of the composite hole transport layer Spin coating a mixed solution of spiro-OMeTAD and FN—Br on a surface of the perovskite active layer; (5) Preparation of a metal electrode Evaporating gold or silver on the composite hole transport layer under vacuum conditions to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

13. A preparation method of the light detection multi-functional device of claim 5, comprising the following steps: (1) Cleaning of the transparent conductive glass performing ultrasonic cleaning on a conductive glass, drying the conductive glass with nitrogen or compressed air, then performing surface cleaning treatment by an ultraviolet light to remove organic matters and enhance film-forming property; (2) Preparation of the composite electron transport layer Preparing a precursor solution from stannous chloride, stannic chloride or titanium tetrachloride, then adding amino-graphene quantum dots for mixing, and spin coating a mixed solution on the transparent conductive glass, then performing heat treatment, and performing ultraviolet ozonation treatment after cooling, where a dangling bond formed by the ozonation treatment may enhance the subsequent film-forming property; (3) Preparation of the perovskite active layer Spin coating a perovskite precursor solution on the composite electron transport layer, and dropwise adding an antisolvent for continuous spin coating when the solvent is wet, and performing heat treatment on the spin coated perovskite film; (4) Preparation of the composite hole transport layer Spin coating a mixed solution of spiro-OMeTAD and FN—Br on a surface of the perovskite active layer; (5) Preparation of a metal electrode Evaporating gold or silver on the composite hole transport layer under vacuum conditions to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

14. A preparation method of the light detection multi-functional device of claim 6, comprising the following steps: (1) Cleaning of the transparent conductive glass performing ultrasonic cleaning on a conductive glass, drying the conductive glass with nitrogen or compressed air, then performing surface cleaning treatment by an ultraviolet light to remove organic matters and enhance film-forming property; (2) Preparation of the composite electron transport layer Preparing a precursor solution from stannous chloride, stannic chloride or titanium tetrachloride, then adding amino-graphene quantum dots for mixing, and spin coating a mixed solution on the transparent conductive glass, then performing heat treatment, and performing ultraviolet ozonation treatment after cooling, where a dangling bond formed by the ozonation treatment may enhance the subsequent film-forming property; (3) Preparation of the perovskite active layer Spin coating a perovskite precursor solution on the composite electron transport layer, and dropwise adding an antisolvent for continuous spin coating when the solvent is wet, and performing heat treatment on the spin coated perovskite film; (4) Preparation of the composite hole transport layer Spin coating a mixed solution of spiro-OMeTAD and FN—Br on a surface of the perovskite active layer; (5) Preparation of a metal electrode Evaporating gold or silver on the composite hole transport layer under vacuum conditions to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

15. The preparation method of claim 10, wherein a solvent in the precursor solution in step (2) is ethanol, and stannous chloride or stannic chloride has a concentration of 0.1-10 wt %, the amino-graphene quantum dot has a concentration of 0.01-1 wt %; and in the step (2), heat treatment refers to heating for 0.5-2 h at 180-270° C., and the ultraviolet ozonation treatment is performed for 5-15 min.

16. The preparation method of claim 11, wherein a solvent in the precursor solution in step (2) is ethanol, and stannous chloride or stannic chloride has a concentration of 0.1-10 wt %, the amino-graphene quantum dot has a concentration of 0.01-1 wt %; and in the step (2), heat treatment refers to heating for 0.5-2 h at 180-270° C., and the ultraviolet ozonation treatment is performed for 5-15 min.

17. The preparation method of claim 12, wherein a solvent in the precursor solution in step (2) is ethanol, and stannous chloride or stannic chloride has a concentration of 0.1-10 wt %, the amino-graphene quantum dot has a concentration of 0.01-1 wt %; and in the step (2), heat treatment refers to heating for 0.5-2 h at 180-270° C., and the ultraviolet ozonation treatment is performed for 5-15 min.

18. The preparation method of claim 13, wherein a solvent in the precursor solution in step (2) is ethanol, and stannous chloride or stannic chloride has a concentration of 0.1-10 wt %, the amino-graphene quantum dot has a concentration of 0.01-1 wt %; and in the step (2), heat treatment refers to heating for 0.5-2 h at 180-270° C., and the ultraviolet ozonation treatment is performed for 5-15 min.

19. The preparation method of claim 14, wherein a solvent in the precursor solution in step (2) is ethanol, and stannous chloride or stannic chloride has a concentration of 0.1-10 wt %, the amino-graphene quantum dot has a concentration of 0.01-1 wt %; and in the step (2), heat treatment refers to heating for 0.5-2 h at 180-270° C., and the ultraviolet ozonation treatment is performed for 5-15 min.

20. The preparation method of claim 10, wherein the mixed solution of spiro-OMeTAD and FN—Br is obtained by dissolving spiro-OMeTAD and FN—Br powder into chlorobenzene, and spiro-OMeTAD has a concentration of 1-10 wt %, and FN—Br has a concentration of 0.01-1 wt %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Description of the Drawings

[0035] FIG. 1 shows a structure diagram of a composite interface transport material-based perovskite photovoltaic, light emission and light detection multi-functional device in the present invention;

[0036] FIG. 2a shows a structural schematic diagram of an energy band of the perovskite multi-functional device in the present invention;

[0037] FIG. 2b shows a structural schematic diagram of an energy band of a solar cell;

[0038] FIG. 2c shows a structural schematic diagram of an energy band of a light emitting diode;

[0039] FIG. 3 is a diagram showing a structure and working principle of the perovskite multi-functional device in Example 1 of the present invention;

[0040] FIG. 4 shows an energy band diagram of an electron transport layer and a hole transport layer of the perovskite multi-functional device in Example 1 of the present invention;

[0041] FIG. 5 shows an I-V graph of the perovskite multi-functional device in Example 1 of the present invention under AM1.5 light illumination;

[0042] FIG. 6 shows a photoresponse diagram of the perovskite multi-functional device in Example 1 of the present invention under AM1.5 light illumination.

DESCRIPTION OF THE EMBODIMENTS

Detailed Description of the Embodiments

[0043] The present invention will be further described in detail with reference to the specific examples, which is used to explain the present invention, but not limited thereto.

Example 1

[0044] As shown in FIG. 1, a perovskite-based photovoltaic, light-emitting and light detection multi-functional device includes a transparent conductive glass, a composite electron transport layer, a perovskite active layer, a composite hole transport layer and a metal electrode layer which are sequentially arranged in a stacked manner from bottom to top.

[0045] A preparation method of the perovskite-based photovoltaic, light-emitting and light detection multi-functional device includes the following steps:

[0046] (1) Cleaning of an ITO glass: an ITO glass having a square resistance of 10Ω, light transmittance of 90% and a thickness of 1.1 mm was chosen, and subjected to ultrasonic cleaning for 5 min successively in deionized water, a liquid detergent, acetone and an ethanol solution, then the ITO glass was dried by nitrogen, and treated for 20 min by an UV-ozone cleaner.

[0047] (2) Preparation of the composite electron transport layer: 23 mg SnCl.sub.2.Math.2H.sub.2O and 0.4 mg amino-graphene quantum dots were dissolved into 1 mL ethanol solution (the amino-graphene quantum dot had a concentration of 0.05 wt %, stannous chloride had a concentration of 2.4 wt %, and a mass ratio of stannous chloride to the amino-graphene quantum dot was 190:4), after being dissolved fully, the solution was spin coated on an ITO substrate for 30 s at a rotary speed of 3000 rpm. Finally, the spin coated film was put on a hot plate and heated for 1 h at 230° C., after cooling, put to ultraviolet ozone to be treated for 5 min, thus forming the composite electron transport layer, and the composite electron transport layer had a thickness of 40 nm;

[0048] (3) Preparation of a perovskite film:PbI.sub.2, CH.sub.3NH.sub.3I and DMSO were dissolved into DMF according to a molar ratio of 1:1:1 to obtain a perovskite precursor solution having a concentration of 1.45 mol/ml. After fully dissolving, the perovskite precursor solution was dropped on SnO.sub.2. After spin coating was performed for 10 s at 1000 rpm, the rotary speed was increased to 5000 rpm, and 600 μL diethyl ether was dropwise added at 20-22 s. The spin-coated perovskite film was put on a 100° C. hot plate for heat treatment for 10 min.

[0049] (4) Preparation of the composite hole transport layer: 24 mg spiro-OMeTAD, 0.05 mg FK209 and 1 mg FN—Br powder were dissolved into 1 mL chlorobenzene solvent (spiro-OMeTAD had a mass concentration of 2.1%, FN—Br had a mass concentration of 0.09%, and a mass ratio of spiro-OMeTAD to FN—Br was 24:1). Finally, the spiro-OMeTAD mixed solution was dropped on a surface of the perovskite film, and spin coated for 35 s at a rotary speed of 3000 rpm, and the composite hole transport layer had a thickness of 60 nm;

[0050] (5) Preparation of a metal electrode:gold was evaporated on the spiro-OMeTAD film under a vacuum condition of 1.0×10.sup.−3 Pa, and prepared into a metal electrode having a thickness of 100 nm;

[0051] The above steps were finished to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

[0052] The performance of the perovskite multi-functional device obtain in the example was shown in FIG. 4. (a) in FIG. 4 shows an energy band diagram of the composite electron transport layer; (b) in FIG. 4 shows an energy band diagram of the composite hole transport layer; after doping with amino-graphene quantum dots, the work function of the SnO.sub.2 electron transport layer reduced to 4.25 eV from 4.45 eV. After doping with FN—Br, the work function of spiro-OMeTAD was increased to 5.1 eV from 4.5 eV. The reverse-scanning photoelectric efficiency of the multi-functional device was 21.54%, and the forward scanning result was 20.88%, as shown in FIG. 5. The luminous efficiency of the device before and after optimization was respectively 0.2% and 4.3%, as shown in (a) in FIG. 6, and (b) in FIG. 6 was fluorescence emission spectrum of the multi-functional device, and the light emission peak position was 772 nm.

Example 2

[0053] In this example, the transparent electrode used was an FTO conductive glass. Other steps were the same as those in Example 1, and the reverse-scanning photoelectric efficiency was 20.8% and the forward scanning result was 20.2%. The luminous efficiency was 1.8%.

Example 3

[0054] A preparation method of a perovskite-based photovoltaic, light-emitting and light detection multi-functional device includes the following steps:

[0055] (1) Cleaning of an ITO glass: an ITO glass having a square resistance of 10Ω, light transmittance of 90% and a thickness of 1.1 mm was chosen, and subjected to ultrasonic cleaning for 5 min successively in deionized water, a liquid detergent, acetone and an ethanol solution, then the ITO glass was dried by nitrogen, and treated for 20 min by an UV-ozone cleaner.

[0056] (2) Preparation of the composite electron transport layer: 23 mg SnCl.sub.2.Math.2H.sub.2O and 0.5 mg amino-graphene quantum dots were dissolved into 1 mL ethanol solution (the amino-graphene quantum dot had a concentration of 0.06 wt %, stannous chloride had a concentration of 2.4 wt %, and a mass ratio of stannous chloride to the amino-graphene quantum dot was 38:1), after being dissolved fully, the solution was spin coated on an ITO substrate for 30 s at a rotary speed of 3000 rpm. Finally, the spin coated film was put on a hot plate and heated for 1 h at 200° C., after cooling, put to ultraviolet ozone to be treated for 5 min, and the composite electron transport layer had a thickness of 40 nm;

[0057] (3) Preparation of a perovskite film:PbI.sub.2, NH.sub.2CH.sub.2NH.sub.3I (or CH.sub.3NH.sub.3I, and the like) and DMSO were dissolved into a DMF solution according to a ratio of 1:1:1, and the concentration was 1.45 mol/ml. After the solution was dissolved fully, the perovskite precursor solution was dropped on SnO.sub.2. Spin coating was performed for 10 s at 1000 rpm, the rotary speed was increased to 5000 rpm, and 600 μL diethyl ether was dropwise added at 20-22 s. The spin-coated perovskite film was put on a 100° C. hot plate for heat treatment for 10 min.

[0058] (4) Preparation of the composite hole transport layer: 75 mg spiro-OMeTAD, 0.05 mg FK209 and 2 mg FN—Br powder were dissolved into 1 mL chlorobenzene solvent (spiro-OMeTAD had a mass concentration of 6.3%, FN—Br had a mass concentration of 0.17%, and a mass ratio of spiro-OMeTAD to FN—Br was 75:2). Finally, the Spiro-OMeTAD mixed solution was dropped on a surface of the perovskite film, and spin coated for 35 s at a rotary speed of 3000 rpm, and the composite hole transport layer had a thickness of 200 nm;

[0059] (5) Preparation of a metal electrode:gold was evaporated on the spiro-OMeTAD film under a vacuum condition of 1.0×10.sup.−3 Pa, and prepared into a metal electrode having a thickness of 100 nm;

[0060] The above steps were finished to obtain the perovskite-based photovoltaic, light-emitting and light detection multi-functional device.

[0061] The reverse-scanning photoelectric efficiency of the perovskite multi-functional device obtained in this example was 20.7%, and forward scanning result was 20.4%. The luminous efficiency was 4.2%.

Example 4

[0062] In this example, SnO.sub.2 heat treatment temperature was 230° C. Other steps were the same as those in Example 3, the reverse-scanning photoelectric efficiency of the perovskite multi-functional device obtained in this example was 21.1%, and forward scanning result was 20.7%, and the luminous efficiency was 2.9%.

Example 5

[0063] In this example, 75 mg spiro-OMeTAD, 0.05 mg FK209 and 0.75 mg FN—Br powder were dissolved into 1 mL chlorobenzene solvent (through calculation, spiro-OMeTAD had a mass concentration of 6.3%, FN—Br had a mass concentration of 0.063%, and a mass ratio of spiro-OMeTAD to FN—Br was 100:1). Other steps were the same as those in Example 3, the reverse-scanning photoelectric efficiency of the perovskite multi-functional device obtained in this example was 21.3%, and forward scanning result was 20.1%, and the luminous efficiency was 2.2%.

Example 6

[0064] In this example, 10 mg amino-graphene quantum dots and 100 mg stannous chloride were dissolved into 1 mL ethanol solution. 2 mg FN—Br and 100 mg spiro-OMeTAD were dissolved into 1 mL chlorobenzene (through calculation, the amino-graphene had a concentration of 0.01 wt %, stannous chloride had a concentration of 0.1 wt %, and a mass ratio of stannous chloride to the amino-graphene quantum dots was 10:1, FN—Br had a concentration of 0.16 wt %, spiro-OMeTAD had a concentration of 8.3 wt %, and a mass ratio of spiro-OMeTAD to FN—Br was 50:1). Other steps were the same as those in Example 3, the reverse-scanning photoelectric efficiency of the perovskite multi-functional device obtained in this example was 20.4%, and the forward scanning result was 19.6%, and the luminous efficiency was 2.8%.

Example 7

[0065] In this example, 0.09 mg amino-graphene quantum dots and 910 mg stannous chloride were dissolved into 1 mL ethanol solution, and 12.3 mg FN—Br and 123 mg spiro-OMeTAD were dissolved into 1 mL chlorobenzene (through calculation, in this example, the amino-graphene had a concentration of 0.01 wt %, stannous chloride had a concentration of 10 wt, and a mass ratio of the two was 1:1000, spiro-OMeTAD had a concentration of 10 wt %, FN—Br had a concentration of 1 wt %, and a mass ratio of the two was 10:1); other steps were the same as those in Example 3. The reverse-scanning photoelectric efficiency of the perovskite multi-functional device obtained in this example was 20.1%, and the forward scanning result was 19.3%, and the light-emitting external quantum efficiency was 2.1%.

Example 8

[0066] In this example, 9 mg amino-graphene quantum dots and 91 mg stannous chloride were dissolved into 1 mL ethanol solution, and 0.123 mg FN—Br and 123 mg spiro-OMeTAD were dissolved into 1 mL chlorobenzene (through calculation, in this example, the amino-graphene had a concentration of 1 wt %, stannous chloride had a concentration of 10 wt, and a mass ratio of the two was 1:10, spiro-OMeTAD had a concentration of 10 wt %, FN—Br had a concentration of 0.01 wt %, and a mass ratio of the two was 1000:1); other steps were the same as those in Example 3. The reverse-scanning photoelectric efficiency of the perovskite multi-functional device obtained in this example was 19.8%, and the forward scanning result was 19.0%, and the luminous efficiency was 1.9%.

Comparative Example 1

[0067] In this example, no FN—Br was added in the preparation of a hole transport layer, and other steps were the same as those in Example 1. The performance result of the obtained device was shown in FIGS. 5 and 6; the reverse-scanning photoelectric efficiency was 17.4%, and the forward scanning result was lower than 15%, and the luminous efficiency was only 0.2%.

Comparative Example 2

[0068] In this example, no graphene quantum dot was added in the preparation of an electron transport layer, and other steps were the same as those in Example 1. The performance result of the obtained device was shown in FIGS. 5 and 6; the reverse-scanning photoelectric efficiency was 20.2%, and the forward scanning result was lower than 19.5%, and the luminous efficiency was only 1.7%.

[0069] The specific examples above are used to describe the technical solution and beneficial effects of the present invention. It should be understood that the above examples are merely detailed embodiments of the present invention, but are not intended to limit the present invention. Any amendment, equivalent replacement, improvement and the like made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.