Photoelectric conversion devices

Abstract

To provide a novel polymer-graphene oxide composite material that contributes to improved energy conversion efficiency and manufacturing methods for the polymer-graphene oxide composite material.SOLUTION: In a polymer-graphene oxide composite material in which a composite of polymer and graphene oxide is dispersed in a solvent, the polymer is selected from polymethyl methacrylate, polystyrene, spirobifluorene (spiro-MeOTAD), polyvinyl alcohol, poly(acrylamide), poly(e-caprolactone), polylactic acid, and poly(lactide-co-glycolide), and the solvent is selected from isopropanol, ethyl acetate, acetone, chloroform, and tetrahydrofuran.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides Photoelectric conversion devices Regarding. [Background technology]

[0002] Lead halide perovskite semiconductors have attracted attention as nanocrystalline structures with high photoelectric conversion efficiency. Optical devices using halide perovskite crystals can be fabricated by solution coating and are low-cost, but improving their stability remains a challenge. Various hole-transporting materials are being researched to ensure stable operation of perovskite solar cells.

[0003] In solar cells using organic lead halide perovskite, a configuration has been proposed in which a polymethyl methacrylate (PMMA) layer is inserted between the perovskite layer and the hole transport layer to improve energy conversion efficiency (see, for example, Non-Patent Document 1). On the other hand, in solar cells using lead sulfide (PbS) quantum dots, a configuration has been proposed in which a graphene oxide layer is inserted between the light absorption layer and the anode to function as the hole transport layer (see, for example, Non-Patent Document 2), and a configuration in which a composite of graphene oxide and PEDOT:PSS (polyethylenedioxythiophene:polystyrenesulfonate) is used as the hole transport layer (see, for example, Non-Patent Document 3). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] J. Phys. Chem. C 2017, 121, 1562-1568 [Non-patent document 2] Organic Electronics 2018, 58, 270-275 [Non-patent document 3] Nanoscale, 2016, 8, 1513-1522 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a new polymer-graphene oxide composite material that contributes to improving energy conversion efficiency, and a method for producing the same. [Means for solving the problem]

[0006] In one embodiment, in a polymer-graphene oxide composite material in which a composite of a polymer and graphene oxide is dispersed in a solvent, the polymer is selected from polymethyl methacrylate, polystyrene, spirobifluorene (spiro-MeOTAD), polyvinyl alcohol, poly(acrylamide), poly(e-caprolactone), polylactic acid, and poly(lactide-co-glycolide); The solvent is selected from isopropanol, ethyl acetate, acetone, chloroform, and tetrahydrofuran.

[0007] In another embodiment, a method for making a polymer-graphene oxide composite comprises: Dissolving a powder of a polymer selected from polymethyl methacrylate, polystyrene, spiro-MeOTAD, polyvinyl alcohol, poly(acrylamide), poly(e-caprolactone), polylactic acid, and poly(lactide-co-glycolide) in a solvent selected from isopropanol, ethyl acetate, acetone, chloroform, and tetrahydrofuran; Graphene oxide powder is added to the solvent in which the polymer powder is dissolved, and the mixture is subjected to ultrasonic treatment to obtain a suspension in which a composite of the polymer and graphene oxide is dispersed. [Effects of the Invention]

[0008] A new polymer-graphene oxide (GO) composite material that contributes to improving energy conversion efficiency and a method for producing it have been developed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating the fabrication process of a polymer-GO composite material according to an embodiment. [Figure 2] Schematic diagram of a sample made using a PMMA-GO composite material. [Figure 3] FIG. 3 shows the Fourier transform infrared (FTIR) spectrum of the sample in FIG. 2, along with the FTIR spectra of a PMMA-only sample and a GO-only sample. [Figure 4] This is an atomic force microscope (AFM) image of the PMMA-GO layer after coating and annealing. [Figure 5] FIG. 10 is a diagram showing a comparison of the optical absorption spectrum of a sample according to an embodiment with that of a sample according to a comparative example. [Figure 6] FIG. 2 is a diagram showing a photoelectron yield spectroscopy (PYS) spectrum of a sample according to an embodiment in comparison with a PYS spectrum of a sample according to a comparative example. [Figure 7] FIG. 1 is a band structure diagram when a PMMA-GO layer according to an embodiment is applied to a photoelectric conversion device. [Figure 8] Schematic diagram of a sample used for space charge limited current (SCLC) measurements. [Figure 9] FIG. 1 shows the results of measuring SCLC. [Figure 10] FIG. 10 is a diagram showing the hole mobility of a quantum dot layer obtained by SCLC measurement. [Figure 11] FIG. 10 is a diagram showing the defect density of a quantum dot layer obtained by the SCLC measurement method. [Figure 12] FIG. 1 is a schematic diagram of a photoelectric conversion device to which a PMMA-GO composite material according to an embodiment is applied. [Figure 13] FIG. 13 shows the C-2-V characteristics of the device in FIG. 12 compared with those of a photovoltaic device without a PMMA-GO coating. [Figure 14] FIG. 1 is a schematic diagram of another photoelectric conversion device to which the PMMA-GO composite material of the embodiment is applied. [Figure 15] FIG. 15 shows the current-voltage characteristics of the device of FIG. [Figure 16] FIG. 1 is a graph showing the power conversion efficiency (PCE) of a photovoltaic device using a PMMA-GO coating according to an embodiment, compared with the PCE of a device without a PMMA-GO coating. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows examples for embodying the technical concept of the present invention, and is not intended to limit the present invention to the following configurations and numerical values.

[0011] FIG. 1 is a schematic diagram illustrating the steps for preparing a polymer-GO composite 15 according to an embodiment. In this embodiment, PMMA is used as the polymer to prepare the PMMA-GO composite 15. Solvents that can be used to disperse the PMMA-GO composite include isopropanol, ethyl acetate, acetone, chloroform, and tetrahydrofuran. In the following embodiment, isopropanol is used to prepare the PMMA-GO composite 15.

[0012] 10 mg of PMMA powder 12 is added to 10 mL of isopropanol 11 and stirred at room temperature until the PMMA powder 12 is completely dissolved. In the actual sample preparation process, 10 mg of PMMA powder 12 is dissolved in 10 mL of isopropanol 11 by stirring at room temperature for 2 hours. PMMA powders of various sizes are commercially available. In this embodiment, PMMA powder with an average molecular weight of approximately 15,000 is used.

[0013] Next, 5 mg of GO powder 14 is added to the isopropanol solution 13 in which PMMA powder 12 is dissolved, and ultrasonic treatment is carried out for 30 to 90 minutes, preferably 40 to 80 minutes, more preferably 50 to 70 minutes. Thereby, a PMMA-GO composite material 15, which is a suspension in which PMMA-GO composites are dispersed in isopropanol, is obtained. Various nanopowders of GO are commercially available. In the embodiment, GO nanopowder with an average size of 6 to 14 μm manufactured by Tokyo Chemical Industry Co., Ltd. is used.

[0014] The PMMA-GO composite is a copolymer of PMMA dispersed in isopropanol and GO. The amounts of PMMA powder 12 and GO powder 14 to be added can be adjusted according to the amount of isopropanol 11. The weight ratio of PMMA powder 12 to GO powder 14 is 5 / 1 to 2 / 1, and mixing in the range of 5 / 1 to 5 / 2 may also be possible.

[0015] Even when the PMMA-GO composite material 15 obtained by the method of FIG. 1 is left in the air at room temperature for 30 minutes or more, there is no change in the color, state, etc. of the suspension, and the stability of the PMMA-GO composite and the stability of the dispersion in the suspension are confirmed.

[0016] By combining a polymer such as PMMA and GO, the excellent properties of graphene, that is, the property of having a certain absorption for light in a wide wavelength range due to a specific band structure and a very high electron mobility can be imparted to a photoelectric conversion device. In order to evaluate the presence of the PMMA-GO composite and its optical and electrical properties, a sample is prepared using the PMMA-GO composite material 15 produced by the method of FIG. 1.

[0017] <Confirmation of PMMA-GO layer> FIG. 2 is a schematic diagram of a sample 20 prepared using the PMMA-GO composite material 15. A colloidal quantum dot (CQD) solution of lead sulfide (PbS) is applied onto a glass substrate 21 to form a CQD layer 23. PbS quantum dots have a wide absorption spectrum range in the near infrared region and are applicable to a photoactive layer of a solar cell, an infrared light-emitting element, a photodetector, etc.

[0018] A 100 μL drop of PMMA-GO composite material 15 is placed on the PbS CQD layer 23 and left for 1 second. Next, the material is spin-coated for 15 minutes at a speed of 5000 rpm / s (starting at 5500 rpm). After spin-coating, the material is immediately annealed at 70°C for 2 minutes using a hot plate. This results in a PMMA-GO layer 24 with a thickness of approximately 10 nm being formed on the CQD layer 23. A hole-transport layer 25 of polyethylenedioxythiophene (PEDOT) is then formed on the PMMA-GO layer 24 by spin-coating.

[0019] To confirm the presence of a PMMA-GO composite, we prepared two samples: one with a PMMA layer between the CQD layer 23 and the hole transport layer 25, and the other with a GO layer between the CQD layer 23 and the hole transport layer 25. The former sample corresponds to the structure described in Non-Patent Document 1, and the latter sample corresponds to the structure described in Non-Patent Document 2.

[0020] 3 shows the FTIR spectrum of the sample having the PMMA-GO layer 24 of the embodiment, along with the FTIR spectra of the sample using the PMMA layer and the sample using the GO layer. -1 A C=C bond peak was observed at 3419 cm -1 The stretching vibration of the -OH group specific to PMMA is observed at 2990cm. -1 and 2950cm -1 , the axial strain specific to aliphatic carbon CH x The vibration of the bond is observed. The results in Figure 3 confirm that a PMMA-GO layer 24 in which PMMA and GO are bonded is formed.

[0021] Figure 4 shows AFM images of the PMMA-GO layer after spin coating and annealing. Figures 4A and 4B show AFM images of the same sample at different in-plane positions. By applying the PMMA-GO composite material 15 of the embodiment, in which PMMA-GO complexes are dispersed, onto the CQD layer 23 and annealing it, the surface of the CQD layer 23 is almost completely covered with the PMMA-GO layer 24. It can also be seen that the surface of the CQD layer 23 is planarized by the PMMA-GO layer 24. This AFM image confirms that the PMMA-GO layer 24 formed from the PMMA-GO composite material 15 of the embodiment protects the interface of the PbS quantum dots in the CQD layer 23 while improving contact with the hole transport layer 25.

[0022] FIG. 5 shows the optical absorption spectrum of Sample C of the embodiment, along with the optical absorption spectra of Comparative Samples A and B. The horizontal axis represents photon energy (eV), and the vertical axis represents the absorption coefficient α. Sample C of the embodiment is a sample in which a PbS CQD layer 23 is coated with PMMA-GO, annealed, and then washed with acetonitrile (ACN). Comparative Sample A is a sample that is not washed with ACN or coated with PMMA-GO, and has a hole transport layer 25 formed on the PbS quantum dot CQD layer 23. Comparative Sample B is a sample that is not coated with PMMA-GO and has been washed with ACN.

[0023] In sample B, the CQD layer 23 was cleaned with ACN without a PMMA-GO coating, resulting in an increased Urbach energy Eu of 31 meV. In contrast, in sample C of the embodiment, the CQD layer 23 is protected by the PMMA-GO layer 24, so even after ACN cleaning, the Urbach energy Eu is low at 23 meV. In sample A, although not coated with PMMA-GO, no ACN cleaning was performed, resulting in less damage to the CQD layer 23 and a low Urbach energy Eu of 24 meV.

[0024] The Urbach energy is expressed as the slope of the spectral tail in the region where the absorption coefficient α rapidly decreases. The smaller the Urbach energy, i.e., the steeper the rise in the absorption coefficient α, the less disorder there is in the atomic arrangement and the fewer defects there are. The results in Figure 5 show that the PMMA-GO layer 24 of the embodiment protects the CQD layer 23 and suppresses the occurrence of defects.

[0025] Figure 6 shows the PYS spectrum of sample C according to the embodiment, along with the PYS spectra of comparative samples A and B. As in Figure 5, sample C is a sample that was coated with PMMA-GO and then washed with ACN. Sample A is a sample that was neither coated with PMMA-GO nor washed with ACN, and sample B is a sample that was not coated with PMMA-GO but was washed with ACN. The horizontal axis represents the energy near the valence band, and the vertical axis represents the density of states.

[0026] Compared to sample A, which was not cleaned with ACN, sample B without a PMMA-GO coating exhibited an increased density of states near the valence band of the CQD layer 23, i.e., an increased hole trap level density. In contrast, sample C, an embodiment of the present invention, exhibits a significantly reduced hole trap level density in the CQD layer 23, even after ACN cleaning, due to the introduction of a PMMA-GO layer 24 at the interface of the CQD layer 23. These measurement results demonstrate that the PMMA-GO layer 24 of the embodiment not only protects the QD layer but also passivates the surface of the PbS quantum dots.

[0027] Figure 7 shows the band structure of a photovoltaic device incorporating a PMMA-GO layer 24 according to an embodiment of the present invention. Based on the structure of sample 20 shown in Figure 2, ZnO is placed beneath the PbS CQD layer 23 as a hole-blocking or electron-transporting layer. A PbS-ethylenediaminetetraacetic acid (EDT) layer is used as the hole-transporting layer 25. By incorporating the PMMA-GO layer 24 between the CQD layer 23 and the hole-transporting layer 25, a gradient energy level favorable for hole transport is formed at the interface between the hole-transporting layer 25 and the CQD layer 23. The high hole mobility in the PMMA-GO layer 24 and the hole-transporting layer 25 significantly improves the current extraction rate of the device.

[0028] <Evaluation of electrical characteristics> Figure 8 is a schematic diagram of a sample 30 used in space-charge-limited current (SCLC) measurements. The sample 30 has a device structure that extracts holes as minority carriers. The sample 30 has a hole-blocking layer 32, a PbS CQD layer 33, a PMMA-GO layer 34, and a hole-transport layer 35 stacked in this order on a first electrode 31. A second electrode 36 is provided on the hole-transport layer 35.

[0029] The first electrode 31 is a 400 nm thick indium tin oxide (ITO) layer. The hole-blocking layer 32 is a 40 nm thick PEDOT:PSS layer. The CQD layer 33 is a PbS quantum dot layer with a thickness of 450 nm. The PMMA-GO layer 34 is a 10 nm thick layer obtained by applying and annealing a PMMA-GO composite material 15. After annealing the PMMA-GO layer 34, the surface is washed with ACN to form a hole-transport layer 35. The hole-transport layer 35 is a 40 nm thick PEDOT:PSS layer. The second electrode 36 is a 100 nm thick gold (Au) layer. The thicknesses of these layers are design values ​​and include manufacturing tolerances.

[0030] Figure 9 shows the SCLC measurement results for Sample 30 along with those for the comparative example. Sample C is Sample 30 in Figure 8. Comparative Sample A is a sample that was neither coated with PMMA-GO nor washed with ACN. Comparative Sample B is a sample that was washed with ACN without forming a PMMA-GO layer.

[0031] The horizontal axis of Figure 9 represents voltage (V), and the vertical axis represents the SCLC current density (J). When the injection barrier is low and a large amount of charge exists within the device, these become space charges, which relax the electric field. When current limitation becomes dominant due to this field relaxation, the current is called SCLC. Figure 9 shows that the SCLC current density of Sample C, an embodiment of the present invention, is low, while the SCLC current density of Sample B, which was washed with ACN without a PMMA-GO layer, is high.

[0032] Based on the JV characteristics in Figure 9, the hole mobility and defect density in the space charge limited region are automatically calculated. Figures 10 and 11 show the hole mobility and defect density, respectively, of the CQD layer 23 obtained by the SCLC measurement method in Figure 9. Referring to Figure 10, in the embodiment of Sample C, the introduction of the PMMA-GO layer 34 increases the hole carrier density in the hole transport layer 35, promoting hole transport.

[0033] Sample A, which was not cleaned with ACN, suffered little damage to the CQD layer 23 even without the PMMA-GO layer 24, resulting in a high hole carrier density and a hole mobility similar to that of Sample C. On the other hand, Sample B, which was cleaned with ACN but did not have the PMMA-GO layer 34, suffered damage to the CQD layer 23 due to ACN, and did not achieve sufficient hole carrier density. The hole mobility of Sample C in this embodiment is 2.4 times that of Sample B.

[0034] 11 , in sample C of the embodiment, the CQD layer 33 is protected and the surface is passivated by the PMMA-GO layer 34, resulting in a low defect density in the CQD layer 33. In sample B, which was cleaned with ACN without the PMMA-GO layer 34, the CQD layer 33 is damaged by the ACN, resulting in a high defect density in the CQD layer 33. In sample A, which was not cleaned with ACN, the CQD layer 23 is less damaged even without the PMMA-GO layer 24, resulting in a lower defect density compared to sample B, but not as low as sample C of the embodiment.

[0035] 9 to 11, it was confirmed that the use of the PMMA-GO layer 24 according to the embodiment passivates the interface between the PbS CQD layer 23 and the hole transport layer 25, reducing the interface defect density and improving hole mobility. A low interface defect density means that recombination at the interface is suppressed, improving hole collection efficiency.

[0036] <Application to photoelectric conversion devices> 12 is a schematic diagram of a photoelectric conversion device 50 fabricated using a PMMA-GO composite material 15 according to an embodiment. The photoelectric conversion device 50 is, for example, a solar cell device. The photoelectric conversion device 50 includes a first electrode 51 on which a ZnO layer 52, a PMMA-GO layer 54, a CQD-EDT layer 53, and a second electrode 56 are stacked in this order.

[0037] The first electrode 51 is formed of a transparent conductive film such as fluorine-doped tin oxide (FTO). The ZnO layer 52 is 50 nm thick and serves as a hole-blocking layer. The PMMA-GO layer 54 is formed by spin-coating and annealing the PMMA-GO composite material 15 of the embodiment and has a thickness of 10 nm. The PMMA-GO layer 54 acts as a barrier to electrons and promotes hole transport. By incorporating PMMA-GO as an underlayer of the CQD-EDT, damage to the CQD layer can be suppressed. The process of fabricating the CQD-EDT layer typically involves multiple uses of ACN, which damages the CQD photoactive layer. Introducing PMMA-GO as an underlayer of the CQD-EDT can suppress this damage. Furthermore, the energy level alignment at the interface between the CQD photoactive layer and the CQD-EDT layer allows for efficient hole extraction. The CQD-EDT layer 53 has the functions of both a photoactive layer and a hole transport layer and is 250 nm thick. The second electrode 56 is a 100 nm thick Au electrode.

[0038] FIG. 13 shows the C of the photoelectric conversion device 50 of FIG. -2 The -V characteristics (data point E) are compared with the C of the device without the PMMA-GO layer. -2 The figure shows a comparison with the -V characteristic (data point D). Here, C is the capacitance generated in the depletion layer, which can be measured by the well-known impedance method. -2 -V characteristic slope and 1 / C 2 The intersection with the axis at 0 is the built-in voltage, which indicates the potential difference across the depletion layer.

[0039] In the photoelectric conversion device 50 of the embodiment, the introduction of the PMMA-GO layer 54 increases the hole density of the CQD-EDT layer 53, which functions as a hole transport layer, to 3.02 × 1016 cm -3 to 4.91 x 10 16 cm -3 13, the carrier mobility of the hole transport layer is increased. This improves the carrier mobility of the hole transport layer. As can be seen from Fig. 13, the PMMA-GO layer 54 of the embodiment also improves the hole mobility when the CQD-EDT layer 53 is used.

[0040] 14 is a schematic diagram of a photoelectric conversion device 60 using the PMMA-GO composite material of the embodiment. The photoelectric conversion device 60 is, for example, a solar cell device. The photoelectric conversion device 60 includes a first electrode 61, a ZnO layer 62, a CQD layer 63, a PMMA-GO layer 64, a CQD-EDT layer 65, and a second electrode 66 stacked in this order on the first electrode 61.

[0041] The first electrode 51 is formed of a transparent conductive film such as fluorine-doped tin oxide (FTO). The ZnO layer 52 is 50 nm thick and serves as a hole-blocking layer. The CQD layer 63 is a PbS quantum dot layer and functions as a photoactive layer (or light-absorbing layer). The CQD layer 63 is 450 nm thick. The PMMA-GO layer 64 is formed by spin-coating and annealing the PMMA-GO composite material 15 of the embodiment and has a thickness of 10 nm. The CQD-EDT layer 65 is a hole-transporting layer and has a thickness of 50 nm. The second electrode 66 is a 100 nm thick Au electrode.

[0042] FIG. 15 shows the current-voltage characteristics of the photoelectric conversion device 60 of FIG. 14. The white circles in the figure represent data points for the forward scan, and the black circles represent data points for the reverse scan. Under light irradiation, the potential is scanned between 0.0 V and 0.7 V. The measurement results for both the forward scan and the reverse scan are shown. The open circuit voltage Voc, i.e., the voltage value at which the current density becomes zero, is 0.65 V for both the forward scan and the reverse scan. The short circuit current density Jsc, i.e., the current density at zero voltage, is 32.3 mA / cm for the forward scan. 2 , 31.9 mA / cm in reverse scan 2 The short-circuit current density reported in Non-Patent Documents 1 and 2 is 22.5 mA / cm 2Therefore, the short-circuit current density of the photoelectric conversion device 60 according to the embodiment is very high.

[0043] The fill factor (FF) is 71.3% in forward scanning and 71.6% in reverse scanning. The fill factor is the output (maximum output) at the optimal operating point divided by the product of the open-circuit voltage and the short-circuit current, and is expressed as Pmax / Voc×Isc. A fill factor closer to 100% is preferable, but the photoelectric conversion device 60 of the embodiment achieves a fill factor exceeding 70%. The PCE in forward scanning is 14.79%, and the PCE in reverse scanning is 14.84%. PCE is the obtained electrical energy (power) divided by the energy of incident light. Compared to the PCE of 12.87% shown in Non-Patent Document 2 and 9.7% shown in Non-Patent Document 3, the PCE of the photoelectric conversion device 60 of the embodiment is significantly improved.

[0044] FIG. 16 shows the PCE of a photovoltaic device 60 fabricated using the PMMA-GO composite material 15 of the present invention, compared to the PCE of a PbS quantum dot photovoltaic device without the PMMA-GO coating or ACN cleaning. As noted above, the photovoltaic device 60 of the present invention exhibits an average PCE of 14.82% in the forward and reverse directions. In contrast, the device configuration without the PMMA-GO layer (W / O) exhibits a lower PCE than the configuration of the present invention. It can be seen that the use of the PMMA-GO layer increases hole collection efficiency and improves PCE.

[0045] As described above, highly efficient quantum dot solar cells can be realized by passivating the interface between the CQD layer and the hole transport layer with a thin film of PMMA-GO composite. The PMMA-GO composite material 15 of the embodiment can be easily fabricated. A thin film that improves hole mobility can be easily formed by simply applying and annealing the PMMA-GO composite material 15. The PMMA-GO composite material 15 of the embodiment can be applied not only to solar cells but also to general optoelectronic devices that use quantum dots, such as organic electroluminescence (EL) devices and infrared light-emitting devices.

[0046] Instead of isopropanol, ethyl acetate, acetone, chloroform, or tetrahydrofuran can be used as the solvent for preparing PMMA-GO composites. These solvents can also be used to prepare suspensions containing PMMA and GO. In addition to PMMA, other polymers that can form complexes with GO to improve carrier mobility include polystyrene, spirobifluorene (spiro-MeOTAD), polyvinyl alcohol, poly(acrylamide), poly(e-caprolactone), polylactic acid, and poly(lactide-co-glycolide). These polymers can be dissolved in the solvents mentioned above, and GO can be mixed with the resulting solution and sonicated to obtain a suspension of polymer-graphene oxide composites. Coating and annealing this suspension yields a polymer-GO thin film, which can be used to passivate the interface between the photoactive layer and the hole transport layer or the interface between the photoactive layer and the electron transport layer, improving the performance of photovoltaic devices. [Explanation of symbols]

[0047] 11 Isopropanol 12 PMMA powder 13 Isopropanol solution in which PMMA powder 12 is dissolved 14. GO powder 15 PMMA-GO composite material 15 20, 30 samples 31, 51, 61 1st electrode 32 Hole blocking layer 33, 63 CQD layer (photoactive layer) 34, 54, and 64 PMMA-GO layers 35 Hole transport layer 36, 56, 66 2nd electrode 50, 60 Photoelectric conversion devices 52, 62 ZnO layer (electron transport layer) 53 CQD-EDT layer

Claims

1. A first electrode; A second electrode; a photoactive layer disposed between the first electrode and the second electrode; a polymer-graphene oxide composite layer disposed between the photoactive layer and the first electrode or between the photoactive layer and the second electrode; a hole blocking layer or an electron transport layer disposed between the first electrode and the photoactive layer; a hole transport layer disposed between the second electrode and the photoactive layer; and the polymer-graphene oxide composite layer is disposed between the photoactive layer and the hole transport layer. Photoelectric conversion device.

2. A first electrode; A second electrode; a photoactive layer disposed between the first electrode and the second electrode; a polymer-graphene oxide composite layer disposed between the photoactive layer and the first electrode or between the photoactive layer and the second electrode; an electron transport layer disposed between the first electrode and the photoactive layer; and the photoactive layer functions as a hole transport layer, the polymer-graphene oxide composite layer is disposed between the photoactive layer and the electron transport layer; Photoelectric conversion device.

3. A first electrode; A second electrode; a photoactive layer disposed between the first electrode and the second electrode; a polymer-graphene oxide composite layer disposed between the photoactive layer and the first electrode or between the photoactive layer and the second electrode; and The polymer-graphene oxide composite layer is a composite layer of graphene oxide and a polymer selected from polymethyl methacrylate, polystyrene, spirobifluorene (spiro-MeOTAD), polyvinyl alcohol, poly(acrylamide), poly(e-caprolactone), polylactic acid, and poly(lactide-co-glycolide). Photoelectric conversion device.

4. A first electrode; A second electrode; a photoactive layer disposed between the first electrode and the second electrode; a polymer-graphene oxide composite layer disposed between the photoactive layer and the first electrode or between the photoactive layer and the second electrode; and the photoactive layer is formed of lead sulfide colloidal quantum dots; Photoelectric conversion device.

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