CN104037325B - A kind of organic solar batteries and preparation method thereof - Google Patents

Abstract

An organic solar cell, comprising a sequentially stacked substrate, an anode layer, an anode modification layer, a photoelectric active layer, a cathode modification layer and a cathode layer, the photoelectric active layer is based on the blending of organic small molecules and organic polymers to serve as three-phase system of bulk materials. And the preparation method of the solar cell. The present invention not only realizes the broadening of the utilization range of the solar spectrum by utilizing the synergistic effect of the polymer and the small molecule, but also realizes the controllable adjustment of the active layer morphology, as well as the adjustment of the open-circuit voltage and filling factor of the photovoltaic device.

Description

A kind of organic solar cell and preparation method thereof

technical field

The invention relates to a solar cell and a preparation method thereof, in particular to a three-phase system organic thin film solar cell and a preparation method thereof.

Background technique

An organic solar cell is a solar cell whose core part is composed of organic materials. At present, the highest energy conversion efficiency of bulk heterojunction solar cells based on organic small molecule materials has exceeded 8% (A.Kyaw, D.Wang, V.Gupta, W.Leong, L.Ke, G.Bazan, A. Heeger, Acs Nano., 7(2013) 4569), and the energy conversion efficiency of two-phase thin-film solar devices based on polymer materials has also exceeded 9% (S.Liao, H.J, huo, Y.Cheng, S.Chen, Adv. Mater., 25 (2013) 4766). As the active layer material, both D-A type polymers and small molecules have their own advantages. For example, for polymer materials, the advantages include better film-forming properties, light absorption and diversity of composition and structure. In recent years, great progress has been made in the design and synthesis of D-A type polymers, or D-A type organic small molecules and thin-film solar cells based on two-phase systems of such materials. But for the polymer, its crystallization performance is usually poor, so in order to improve the performance of its crystallization usually need to introduce a small amount of 1,8 diiodooctane (DIO) or chloronaphthalene (CN), PDMS (polydimethylsiloxane) Oxane) or other kinds of additives to increase the crystallization of the active layer and improve the morphology of the active layer (Y.Liu, Z.Li, G.He, C.Li, B.Kan, M.Li, Y.Chen, J. Am. Chem. Soc., 135(2013) 8484).

Compared with polymers, the advantages of small organic molecules are: regular structure, good crystallinity, high intrinsic mobility, no difference between different synthetic batches, easier synthesis, purification and molecular modification. Compared with polymers, organic small molecules are easier to form orderly stacks and form a morphology that is conducive to charge transport, thereby obtaining a higher fill factor, but organic small molecules also have corresponding shortcomings, such as better crystallinity It is also easy to cause its large phase separation scale, which is not conducive to the separation of charges, and thus better device performance can be obtained. In order to adjust the crystallinity of organic small molecule materials, it is usually necessary to introduce some other additives. However, since additives such as DIO, CN, and PDMS are all inert elements in the active layer, that is, if these substances are added in excess, they may form traps in the active layer to hinder the separation and transport of charges. This greatly limits the proportion of such materials that can be added and the scope of their applications.

Compared with the two-phase system that requires the introduction of additives to improve the energy conversion efficiency of thin-film solar cell devices, the three-phase photovoltaic device presents a similar but most promising concept. Because compared to improving the morphology of the active layer by introducing inert materials as additives, using active materials with different characteristics to blend, and changing the ratio of the two to adjust the phase separation scale of the photovoltaic device, that is, the morphology of the active layer, and The light-absorbing range of the thin film layer, thereby increasing its exciton generation and obtaining a higher current, has shown great advantages. For example, a three-phase system device based on two different donor materials, one acceptor material, and one donor material and two acceptor materials, effectively avoids the introduction of inert traps, which greatly broadens the doped " The ratio of the "object" material, which in turn increases the adjustable range of various parameters (such as open circuit voltage, short circuit current, fill factor), which also enables us to effectively improve the energy conversion efficiency of the device, and even break the barrier of the two-phase system. The theoretical efficiency limit of the device is possible.

The doping materials currently used in the three-phase system mainly include polymer materials, small molecule materials, dyes, and different types of nanoparticles. Among these materials that can be used as "doping guests", organic small molecule materials have obvious advantages. Because the light absorption range of organic small molecule materials is wide, and the better molecular arrangement and stacking ability provides sufficient prerequisites for the adjustment of the morphology of the active layer and the adjustment of the acceptor interface. This will provide a better path for the transport and collection of carriers so as to improve the short-circuit current and fill factor of the device. However, there is no solar cell that blends small molecule materials with polymers as a three-phase system.

Contents of the invention

One of the purposes of the present invention is to provide an organic solar cell, by introducing an organic small molecule material with a suitable molecular structure and a suitable ratio into the active layer material of a polymer thin film solar cell, or it can be said that by introducing an organic small molecule material based on an organic small The introduction of appropriate polymer materials into the thin-film solar cells of molecular materials can improve the performance of the devices. By using the synergistic effect of polymers and small molecules, not only the broadening of the solar spectrum utilization range is realized, but also the controllable adjustment of the morphology of the active layer, as well as the adjustment of the open circuit voltage and fill factor of photovoltaic devices.

For reaching above-mentioned object, the present invention adopts following technical scheme:

An organic solar cell, comprising a sequentially stacked substrate, an anode layer, an anode modification layer, a photoelectric active layer, a cathode modification layer and a cathode layer, the photoelectric active layer is based on the blending of organic small molecules and organic polymers to serve as A three-phase system of bulk (P-type) materials. Both donor materials can participate in the absorption of photons, the generation of excitons, the separation and collection of charges in the active layer, and the mixing ratio of the two materials can be adjusted arbitrarily.

For the present invention, wherein the polymer can be but not limited to D-A polymer, preferably poly 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b :4,5-b']dithiophen-2-yl)-5-octyl-4H-thiophene[3,4-c]pyrrole-4,6(5H)diketone (abbreviated as PBDTPD-HT, its molecular formula As shown in Figure 1).

The specific synthesis method of PBDTTPD-HT (see literature K.Lu, J.Fang, H.Yan, X.Zhu, Y.Yi, Z.Wei, Organic Electronics, 14(2013) 2652), as follows;

The BDTT chemical reaction process is shown below (references for specific reaction steps and reaction conditions L.Huo, S.Zhang, X.Guo, F.Xu, Y.Li, J.Hou, Angew.Chem.Int.Ed., 50 (2011) 9697):

The TPD chemical reaction process is shown below (specific reaction steps and reaction conditions references Y.Zou, A.Najari, P.Berrouard, S.Beaupré, BR Y. Tao, M. Leclerc, J. Am. Chem. Soc., 132(2010) 5330):

The chemical reaction process of compound 11 is as follows:

Compound 9 (2.1g, 5mmol) and compound 10 (5.72g, 12.5mmol) were dissolved in toluene, and 80mg of tetrakis(triphenylphosphine)palladium was added quickly after 10 minutes of argon gas flow, pumped and inflated three times, and the temperature rose to 110°C , and reacted in the dark under the protection of argon for 24 hours. After the reaction, the sample was loaded by dry method, and the mixed solution of CH ₂ Cl ₂ /n-hexane with a volume ratio of 6:1 was used as eluent, and the product was separated by silica gel chromatography to obtain a yellow solid (1.49 g, yield 51%).

MS(MALDI):m/z=597.1HNMR(400MHz,CDCl3,d):7.87(s,2H),7.02(s,2H),3.67(t,2H),2.66(t,4H),1.67–1.61 (m,6H), 1.39–1.26(m,30H), 0.91(t,9H).

The chemical reaction process of compound 12 is as follows:

Compound 11 (0.6g, 1.0mmol) was dissolved in 15ml of a mixed solution of CHCl ₃ /CH ₃ COOH with a volume ratio of 1:1, NBS (N-bromosuccinimide) (0.39g, 2.2mmol) was added and stirred for 3 Hour. After the reaction was completed, _CHCl3 was extracted 3 times, the organic phase was rotatably evaporated to remove the solvent, and dichloromethane/petroleum ether volume ratio 6:1 was used as eluent, and the product was separated by silica gel chromatography, a colorless transparent liquid (0.6g, produced rate 80%).

MS(MALDI):m/z=753.1H NMR(400MHz,CDCl3,d):7.62(s,2H),3.66(t,2H),2.69(t,4H),1.66–1.60(m,6H), 1.33–1.28(m,30H),0.87(t,9H).

The chemical reaction process of the polymer PBDTTPD-HT is as follows, and the specific reaction steps and reaction conditions are as follows:

In a 50mL three-neck flask, add 162.7mg (0.18mmol) of compound 6 and 136.2mg (0.18mmol) of compound 12, then add 16mL of ultra-dry toluene and 4mL of ultra-dry N,N-dimethylformamide, and pass argon for 20 minutes Afterwards, 15 mg of tetrakis(triphenylphosphine)palladium was quickly added, pumped and inflated three times, and then the temperature was slowly raised to 110° C., and reacted in the dark under the protection of argon for 24 hours. After the reaction is completed and the reaction system is naturally cooled to room temperature, the reaction solution is dropped into 200mL of methanol for precipitation, and the precipitate is filtered out and transferred to a Soxhlet extractor, followed by methanol, acetone, n-hexane and chloroform. Extraction, concentration of the final chloroform extract, and dropwise addition to 200 mL of methanol for re-precipitation, filtration of precipitates and vacuum drying, and finally 125.0 mg of polymer P64 was obtained with a yield of 60%. The number-average molecular weight Mn of the polymer was measured at room temperature by gel size exclusion chromatography with tetrahydrofuran as the mobile phase, Mn=14.6KDa, and the degree of dispersion PDI=1.6.

Small organic molecules can be but not limited to small molecules of type D-A, preferably dioctyl-3,3'-(5",5""-(4,8-bis(5-(2-ethylhexyl)thiophene -2-yl)benzo[1,2-b:4,5-b']thiophene-2,6-diyl)bis(3,3″-dioctyl-[2,2':5', 2″-trithiophene]-5″,5-diyl))bis(2-cyanoethyl ester) (referred to as BDT-C83S-CNCOO), 2,2’-((5″,5″″’- (4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis( 3,3″-dioctyl-[2,2’:5’,2″-trithiophene]-5″,5-diyl))bis(methenylene)bis(3-oxoundecane Cyanogen) (abbreviated as BDT-C83S-CNCO), etc., the molecular formulas of both are as shown in accompanying drawing 1.

The synthesis method of BDT-C83S-CNCOO and BDT-C83S-CNCO two molecules is as follows:

The first is the synthesis of BDTT

The chemical reaction scheme is as follows (references for specific reaction steps and reaction conditions L.Huo, S.Zhang, X.Guo, F.Xu, Y.Li, J.Hou, Angew.Chem.Int.Ed., 50 (2011) 9697.).

and the synthesis of Br3SCHO

The chemical reaction scheme is as follows (references for specific reaction steps and reaction conditions J.Zhou, X.Wan, Y.Liu, G.Long, F.Wang, Z.Li, Y.Zuo, C.Li, Y. Chen, Chem. Mater., 23 (2011) 4666.).

Then get B3SCHO2BDTT

The chemical reaction scheme is as follows (references for specific reaction steps and reaction conditions J.Zhou, Y.Zuo, X.Wan, G.Long, Q.Zhang, W.Ni, Y.Liu, Z.Li, G. He, C. Li, B. Kan, M. Li, Y. Chen, J. Am. Chem. Soc., 135 (2013) 8484.).

Finally, the BDT-C83S-CNCOO molecule is obtained:

The chemical reaction scheme is shown below, and the specific reaction steps and reaction conditions are as follows: under an inert atmosphere, two drops of dry triethylamine were added to compound 11 (364mg, 0.23mmol) in dry CHCl3 (30ml) solution, and then octyl Cyanoethyl ester (455.7 mg, 2.3 mmol). The whole reaction system was heated to 80°C and stirred for 12 hours. After the reaction solution was cooled down, methanol was added for precipitation, centrifuged, and the solid part was dissolved with chloroform, washed with water three times, and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation of the organic phase, petroleum ether: chloroform = 2:3 (volume ratio) was used as eluent, and the product was separated by silica gel chromatography. The product was recrystallized from chloroform and methanol, chloroform and n-hexane to obtain a black solid product (200 mg, 45%).

MS(MALDI–TOF):1933.1,1H NMR(400MHz,CHCl3):8.20(s,2H),7.60-7.64(d,4H),7.30-7.32(m,4H),7.14-7.15(m,4H) ,6.9-6.97(m,2H),4.27-4.31(t,4H),2.77-2.86(m,12H),1.70-1.75(m,14H),1.27-1.38(m,12H), 1.36(m, 76H), 0.85-0.98 (m, 30H). Elemental analysis results: C, 70.76; H, 7.92; N, 1.45; O, 3.31; S, 16.57.

The preparation method of small molecules of other terminal acceptor cyanoethyl esters is the same as above.

For example, the reaction formula of BDT-C83S-CNCO molecule:

The conditions of the synthetic methods of the above compounds PBDTPD-HT, BDT-C83S-CNCOO, and BDT-C83S-CNCO are not limited to the conditions defined above, and can be appropriately adjusted according to the actual situation, as long as the synthetic methods of the target compounds can be completed. in the present invention.

Preferably, the acceptor material in the three-phase system of the photoelectric active layer is (6,6)-phenyl-C61-butyric acid methyl ester and/or (6,6)-phenyl-C71-butyric acid methyl Esters (PC71BM), preferably (6,6)-phenyl-C71-butyric acid methyl ester.

For the present invention, wherein, the content of the polymer in the polymer and small organic molecule blend system is 1wt%-99wt%, such as 5wt%, 9wt%, 15wt%, 30wt%, 50wt%, 70wt%, 85wt%, 90wt%, 96wt%, etc., preferably 10wt%-95wt%.

For the present invention, the thickness of the active layer can be controlled at 40-400nm, such as 43nm, 76nm, 120nm, 165nm, 200nm, 280nm, 395nm and so on.

The purpose of the present invention is also to provide the preparation method of the organic solar cell of the present invention, comprising the following steps:

(1) On a substrate with a conductive layer, preferably a transparent conductive layer (ITO), coat an anode modification layer (such as generally modifying PEDOT:PSS for positive devices) or a cathode modification layer (suitable for the preparation of reverse devices, For example ZnO) post-drying; said drying is preferably carried out on a hot table;

(2) Blending the small organic molecule with the polymer donor material, then blending with the acceptor material, then adding it to the organic solvent, heating and stirring to obtain a mixed solution, and coating the mixed solution in step (1) After treatment on the electrode modification layer, it acts as the active layer of the three-phase system;

(3) On the active layer, prepare the cathode modification layer (compared to the positive device, generally Ca, Ba, LiF, BCP, etc.) or the anode modification layer (compared to the reverse device, generally use MoOx, V ₂ O ₅ , etc.) , and finally evaporate the cathode such as Al, etc. or the anode such as Ag, Au, etc. The vapor deposition can be carried out according to the prior art, and the thickness of the vapor deposition and the vapor deposition conditions can be adjusted according to the prior art.

For the preparation method of the present invention, wherein the solvent is one or a mixture of two or more of chloroform, toluene, chlorobenzene, o-dichlorobenzene, and the like.

Preferably, the heating temperature is 30-70°C, such as 33°C, 42°C, 47°C, 55°C, 62°C, 68°C, etc., preferably 60°C; the heating time is more than 1h, such as 1.5 h, 2.3h, 3.5h, 5h, etc., preferably 2h.

For the preparation method of the present invention, wherein, the coating is spin coating.

For the preparation method of the present invention, wherein, the treatment can select a hot stage for heat treatment;

Preferably, the heating temperature is 50-200°C, such as 55°C, 70°C, 90°C, 105°C, 120°C, 150°C, 185°C, etc., and the heating time is 3min-2h, such as 5min, 15min, 30min, 50min, 1.2h, 1.7h, etc.

For the preparation method described in the present invention, the crystallinity of the polymer will be improved by incorporating the small molecule material in the donor (P-type) material in the active layer as a "guest material" into the system with the polymer material as the main material , so as to improve the size of the phase-separation region, the roughness of the film surface, etc., and finally achieve the improvement of the charge transport and collection of the three-phase system, as well as the fill factor.

For the preparation method of the present invention, when the small molecule material is used as the host material and the polymer material is mixed as the guest material in the active layer material, since the molecular chain of the polymer molecule is relatively long, it will require a relatively long time in the solution. It takes a long time to reach its dynamic equilibrium state, which may act as an obstacle for the rapid aggregation of organic small molecule materials and reach its dynamic equilibrium state, so the phase separation region scale of small molecule materials will also be reduced, compared to the For devices with a two-phase system of organic small molecule materials, the morphology of the active layer of the three-phase system has been improved, so its energy conversion efficiency has been significantly improved.

Usually, the significant improvement of a certain parameter will be at the cost of sacrificing the value of other parameters. However, by studying various parameters in the three-phase system of the present invention, such as the miscibility of the three components, the crystallization state of the active layer film and The scale of phase separation, in-depth understanding of the internal reasons that affect the changes of various parameters in the three-phase system, provides solar cell materials with better mutual solubility, crystallization state of the active layer film, and phase separation scale.

The polymer thin film solar cell with the triple active layer structure provided by the present invention has the following significant advantages:

1. Organic small molecule materials and polymer materials with different maximum absorption peaks can realize effective absorption, conversion and utilization of sunlight in different wavebands, thereby improving the short-circuit current of the device (as shown in accompanying drawing 2, i.e. example 1 result of UV absorption in ).

2. The morphology of the active layer and the phase separation scale are continuously adjusted by changing the ratio of different types of active materials, thereby optimizing the morphology of the active layer (as shown in Figure 5, which is the active layer of the device in Example 1 Atomic force microscope and transmission microscope images of the topography), to achieve the improvement of parameters such as short-circuit current and fill factor, and then improve the energy conversion efficiency of three-phase devices.

3. The structure of the device is the same as that of the solar cell device of the two-phase system, which does not increase the difficulty and cost of the device preparation process.

Description of drawings

Fig. 1 is the molecular formula structure of BDT-C83S-CNCOO, BDT-C83S-CNCO, PBDTTPD-HT, and PC71BM;

Fig. 2 is the BDT-C83S-CNCOO/PBDTTPD-HT/PC71BM three-phase mixed system in example 1, the ultraviolet-visible absorption spectrogram of the film under BDT-C83S-CNCOO and PBDTTPD-H mass ratio is 4:6 and its Compared with the absorption spectrum under the reference conditions (that is, under the blending conditions of the two-phase system of BDT-C83S-CNCOO/PC71BM and PBDTTPD-HT/PC71BM respectively);

Fig. 3 is the BDT-C83S-CNCOO/PBDTTPD-HT/PC71BM three-phase mixed system in example 1, the current-voltage curve of the solar cell under the condition that the mass ratio of BDT-C83S-CNCOO and PBDTTPD-HT is 4:6 and the comparison of the current-voltage curve under the reference conditions (i.e. under the two-phase system of BDT-C83S-CNCOO/PC71BM and PBDTTPD-HT/PC71BM respectively blending conditions)

Fig. 4 is the BDT-C83S-CNCOO/PBDTTPD-HT/PC71BM three-phase mixed system in the example 1, and the external quantum efficiency curve of the solar cell under BDT-C83S-CNCOO and PBDTTPD-HT mass ratio is 4:6; And Its comparison with the external quantum efficiency under the reference conditions (that is, the two-phase systems of BDT-C83S-CNCOO/PC71BM and PBDTTPD-HT/PC71BM were blended separately).

Fig. 5 is the BDT-C83S-CNCOO/PBDTTPD-HT/PC71BM three-phase mixed system in example 1, the three-phase blended film atomic force microscope picture and transmission electron microscope picture under different PBDTTPD-H mass ratios;

Fig. 6 is the BDT-C83S-CNCO/PBDTTPD-HT/PC71BM three-phase mixed system in example 2, the current-voltage curve of the solar cell under the condition that the mass ratio of BDT-C83S-CNCO and PBDTTPD-HT is 1:9; And its comparison with the current-voltage curve under the reference conditions (that is, under the two-phase system of BDT-C83S-CNCO/PC71BM and PBDTTPD-HT/PC71BM respectively blending conditions);

Fig. 7 is the BDT-C83S-CNCO/PBDTTPD-HT/PC71BM three-phase mixed system in example 2, the external quantum efficiency curve of the solar cell under the condition that BDT-C83S-CNCO and PBDTTPD-HT mass ratio are 1:9; And its comparison with the external quantum efficiency curve of the solar cell under the reference conditions (that is, under the two-phase system of BDT-C83S-CNCO/PC71BM and PBDTTPD-HT/PC71BM respectively blended).

detailed description

In order to facilitate understanding of the present invention, the present invention enumerates the following examples. Those skilled in the art should understand that the examples are only used to help understand the present invention, and should not be regarded as specific limitations on the present invention.

Example 1

10 mg of BDT-C83S-CNCOO was added to 1 ml of chloroform, and the solution was heated to 60°C and kept stirring for two hours before use. 10 mg of PBDTPD-HT and 10 mg were added to 1 ml of chloroform, and the solution was heated to 60° C. and kept stirring for two hours before use. 10 mg of PC71BM was added to 1 ml of chloroform, and the solution was heated to 40°C and kept stirring for two hours before use. Take 0.4 ml of BDT-C83S-CNCOO, 0.6 ml of PBDTPD-HT and 0.67 ml of PC71BM solution, mix and heat the three solutions to 60°C and keep stirring for two hours before use.

The transparent conductive glass sputtered with ITO was ultrasonically cleaned with deionized water, acetone, and isopropanol for 15 minutes, and then the surface of the substrate was treated with ozone, and then PEDOT:PSS with a thickness of about 40 nm was spin-coated as the anode modification layer. , and dried at 150°C for 15 minutes. The three mixed solutions prepared above were spin-coated on the PEDOT:PSS modified substrate as a photoelectric active layer at 3000 rpm/20 seconds, and then the substrate was placed at 110° C. for 10 minutes and cooled naturally. Finally, vacuum evaporation of 5-20 nanometers of Ca and 70-100 nanometers of aluminum under 2×10 ^-6 Pa is used as a cathode to obtain a polymer thin film solar cell device.

The prepared device is tested under 100 milliwatts per square centimeter of simulated sunlight: 1) The open circuit voltage of the photovoltaic device based on BDT-C83S-CNCOO:PC71BM is 0.968 volts, and the short circuit current is 10.11 milliamperes per square centimeter , the fill factor is 72.63%, and the photoelectric conversion efficiency is 7.48%. 2) The open-circuit voltage of the photovoltaic device based on PBDTPD-HT:PC71BM is 0.99 volts, the short-circuit current is 11.79 milliamperes per square centimeter, the fill factor is 58.14%, and the photoelectric conversion efficiency is 6.85%. 3) The open-circuit voltage of the photovoltaic device based on BDT-C83S-CNCOO:PBDTPD-HT:PC71BM=4:6:6.67 is 0.969 volts, the short-circuit current is 12.17 mA per square centimeter, the fill factor is 71.23%, and the photoelectric conversion efficiency is 8.4%. The corresponding J-V curves and external quantum conversion efficiency curves are shown in Figures 3 and 4, respectively.

Example 2

Add 10 mg of BDT-C83S-CNCO into 1 ml of chloroform, heat the solution to 60° C. and keep stirring for two hours before use. Take 10 mg of PBDTTPD-HT and add it to 1 ml of chloroform, heat the solution to 60°C and keep stirring for two hours before use. 8 mg of PC71BM was added to 1 ml of chloroform, and the solution was heated to 40°C and kept stirring for two hours before use. Take 0.1 ml of BDT-C83S-CNCO, 0.9 ml of PBDTPD-HT and 0.8 ml of PC71BM in chloroform, add 0.03 ml of DIO, heat the mixed solution to 60°C and keep stirring for two hours before use.

The transparent conductive glass sputtered with ITO was ultrasonically cleaned with deionized water, acetone, and isopropanol for 15 minutes, and then the surface of the substrate was treated with ozone, and PEDOT:PSS with a thickness of about 40 nanometers was spin-coated as an anode modification layer. and dried at 150° C. for 15 minutes. The three mixed solutions prepared above were spin-coated on the PEDOT:PSS modified substrate as a photoelectric active layer at 3000 rpm/20 seconds, and then the substrate was placed at 110° C. for 10 minutes and cooled naturally. Finally, vacuum evaporation of 5-20 nanometers of Ca and 70-100 nanometers of aluminum under 2×10 ^-6 Pa is used as a cathode to obtain a polymer thin film solar cell device.

The prepared device is tested under 100 milliwatts per square centimeter of simulated sunlight: 1) The open circuit voltage of the photovoltaic device based on BDT-C83S-CNCO:PC71BM is 0.90 volts, and the short circuit current is 9.04 milliamperes per square centimeter , the fill factor is 60.6%, and the photoelectric conversion efficiency is 5.14%. 2) The open-circuit voltage of the photovoltaic device based on PBDTTPD-HT:PC7:1BM is 0.92V, the short-circuit current is 10.13mA/cm2, the fill factor is 66.29%, and the photoelectric conversion efficiency is 6.43%. 3) The open circuit voltage of the photovoltaic device based on BDT-C83S-CNCO: PBDTPD-HT: PC71BM=1:9:8 is 0.92 volts, the short circuit current is 9.88 mA per square centimeter, the fill factor is 70.62%, and the photoelectric conversion efficiency is 6.79%. The J-V and external quantum conversion efficiency curves of the corresponding results are shown in Figures 6 and 7, respectively.

The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned examples, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow process can be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims (17)

1. a kind of organic solar batteries, including substrate, anode layer, anode modification layer, photoelectric active layer, the negative electrode stacked gradually Decorative layer and cathode layer, it is characterised in that the photoelectric active layer is to be filled based on organic molecule and organic polymer are blended When the three-phase system of donor material；

The polymer is the polymer of D-A type；

The organic molecule is the small molecule of D-A type；

Content of the polymer in polymer and organic molecule co-mixing system is 1wt%-99wt%.

2. organic solar batteries according to claim 1, it is characterised in that the polymer is the poly- (5- (2- of 4,8- bis- Ethylhexyl) thiophene -2- bases) benzo [1,2-b:4,5-b'] Dithiophene -2- bases) -5- octyl group -4H- thiophene [3,4-c] pyrroles - 4,6 (5H) diketones.

3. organic solar batteries according to claim 1, it is characterised in that the organic molecule is dioctyl -3, 3'- (5 ", 5 " "-(4,8- bis- (5- (2- ethylhexyls) thiophene -2- bases) benzene [1,2-b:4,5-b'] bithiophene -2,6- diyls) two (3,3 "-dioctyl-[2,2':5', 2 "-three thiophene] -5 ", 5- diyls)) two (2- cyanaoethyl methacrylates), 2,2'- ((5 ", 5 " " '-(4, 8- bis- (5- (2- ethylhexyls) thiophene -2- bases) benzene [1,2-b:4,5-b'] 1,4-Dithiapentalene -2,6- diyls) two (3,3 "-two is pungent Base-[2,2':5', 2 "-three thiophene] -5 ", 5- diyls)) two (methylene alkenyl) two (3- oxo hendecanes cyanogen).

4. according to the organic solar batteries described in claim any one of 1-3, it is characterised in that the three of the photoelectric active layer Acceptor material in phase system is (6,6)-phenyl-C61- methyl butyrates and/or (6,6)-phenyl-C71- methyl butyrates.

5. organic solar batteries according to claim 4, it is characterised in that in the three-phase system of the photoelectric active layer Acceptor material be (6,6)-phenyl-C71- methyl butyrates.

6. according to the organic solar batteries described in claim any one of 1-3, it is characterised in that the polymer is in polymer It is 10wt%-95wt% with the content in organic molecule co-mixing system.

7. according to the organic solar batteries described in claim any one of 1-3, it is characterised in that the thickness of the active layer is 40-400nm。

8. the preparation method of any one of the claim 1-7 organic solar batteries, comprises the following steps：

(1) dried on the substrate with conductive layer after coated anode decorative layer or cathodic modification layer；

(2) organic molecule and polymer donor material are blended, then are blended with acceptor material, then added in organic solvent, Mixed solution is obtained under heating, stirring condition, by electrode modification layer of the mixed solution coated in step (1), is filled after processing When the active layer of three-phase system；

(3) cathodic modification layer or anode modification layer, last evaporation cathode or anode are sequentially prepared on active layer.

9. preparation method according to claim 8, it is characterised in that the conductive layer is transparency conducting layer.

10. preparation method according to claim 8, it is characterised in that the drying is carried out preferably in thermal station.

11. preparation method according to claim 8, it is characterised in that the organic solvent is chloroform, toluene, chlorobenzene, neighbour One kind or two or more mixture in dichloro-benzenes.

12. according to the preparation method described in claim any one of 8-11, it is characterised in that the temperature of step (2) described heating For 30-70 DEG C；The time of heating is more than 1h.

13. preparation method according to claim 12, it is characterised in that the temperature of the heating is 60 DEG C.

14. preparation method according to claim 12, it is characterised in that the time of the heating is 2h.

15. according to the preparation method described in claim any one of 8-11, it is characterised in that described to be applied to spin coating.

16. according to the preparation method described in claim any one of 8-11, it is characterised in that step (2) processing is selection Thermal station is heated.

17. preparation method according to claim 16, it is characterised in that the temperature of the heating is 50-200 DEG C, heating Time be 3min-2h.