Investigation Of High Performance Organic Solar Cells Via Manipulating Cathode Buffer Layer With Substitution Of Active Materials

Organic solar cells have a wide range of materials and simple preparation processes.In recent years,the improvement of the efficiency of organic solar cells has become a hot spot in the research of organic photovoltaic devices.This paper mainly focuses on improving the photoelectric conversion efficiency of organic solar cells.Exploring ways to improve efficiency through the improvement of the cathode modification layer,the preparation of new materials and components and the ternary strategy.First,the effects of the cathode modification layer and the composite cathode modification layer on the device were studied in the basic organic photovoltaic device.On top of this,the active layer material was replaced,and an organic solar cell with an efficient non-fullerene material PM6:Y7 as the active layer was prepared.,And the fullerene material PC₇₀BM is added as the third component to the non-fullerene system,which effectively improves the electron transport in the device,improves the exciton dissociation efficiency of the device and balances the electron transport,while expanding The absorption spectrum range of the active layer,thereby improving the photoelectric conversion efficiency of the device.The photoelectric characteristics,external quantum efficiency,absorption spectrum of the active layer,and surface morphology of the device were compared.The main research results and innovations of this work can be summarized as:?1?Prepared P3HT:PC₆₁BM inversion polymer solar cell of classic system,by changing the annealing time,annealing temperature and film thickness of ZnO,Sn O₂,PEIE single layer cathode interface layer material film,the optimal single layer cathode interface Layer conditions,the device performance is found to be the best when the single-layer cathode modification layer is ZnO,and the optimal efficiency can reach 3.68%,and then the interface layer materials are further stacked.It is found that the composite cathode modification layer can complement the modification layer performance and effectively Adjusting the interface performance and optimizing the best device using Sn O2/ZnO composite cathode modification layer,the device photoelectric conversion rate reached 3.93%,which is close to the highest international report of P3HT device of4%,and the efficiency of the single layer cathode interface has increased by 25.14%.?2?Using ZnO as the cathode modification layer,an organic photovoltaic device with a new high-efficiency organic material PM6:Y7 as the active layer system was prepared.The efficiency of the device was improved by changing the ratio of the acceptor,the thickness of the active layer,the annealing temperature,and the annealing time.10.87%.In addition,CN was added as an additive in the active layer solution.When the concentration was 2%,the JSC of the device was increased by 5%,and the efficiency was further increased from 14.58%to 15.16%.It was proved that a certain concentration of additives will affect the active layer morphology and make The surface of the film is smoother,and the interface between the electrode and the semiconductor is better.?3?On the optimized PM6:Y7 system binary organic photovoltaic device,doped with 5%fullerene material PC₇₀BM as the third component,the efficiency of the device was increased to 16.02%,FF increased from 67.6%to 70.1%It was found that doping the proper amount of fullerene acceptor can effectively improve the electron transport in the device,improve the exciton dissociation efficiency of the device and balance the electron transport,thereby improving the fill factor of the device,but the proportion of excessive doping PC₇₀BM will destroy the surface morphology of the active layer film,making the series resistance in the device larger,reducing the short-circuit current drop and fill factor.This article includes 32 pictures,17 tables,and 72 references.