The Study On The Efficient Polymer Solar Cells With Solution-processable Electrode Interfacial Materials

In the effective use of solar energy, the solar cells can convert solar energy into electrical energy. The solar cells become one of the most dynamic area of research, is of the fastest growing in recent years. Polymer solar cells (PSCs) have attracted considerable attention because of their potential application in low-cost and largescale modules. At present, the research of the PSCs is focused on improvement of power conversion efficiency (PCE) and device stability for future application. The key points for increasing the PCE and stability are the design and synthesis of high efficiency photovoltaic materials and the construction of new device structures. Research is now focused on the primary between the active layer and the electrode layer. In this paper, in order to solve the existed problems of PSCs and grasp the research direction of PSCs, We choosed that the right alcohol-soluble chelate as an electrode buffer layer of materials in both conventional PSCs, which increased the power conversion efficiency and stability of the PSCs. Research and findings are summarized as follows:1、A simple but efficient method has been first developed for the solution preparation of CrOx as anode buffer layer for polymer photovoltaic cells. The chromium acetylacetonate precursor can be transformed into CrOx upon thermal annealing at～60℃, followed by ultravioletozone treatment. The leakage current of the device with the CrOx anode buffer layer was decreased, and short-circuit current density (Jsc) was significantly increased in comparison with the device wi th the traditional poly (3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) buffer layer. By analyzing the current density-voltage characteristics of the device, it is found that the CrOx anode buffer layer can simultaneously decrease the series resistance and increase the parallel resistance of the device, in comparison with the device with PEDOT:PSS anode buffer layer. For the cells based on poly (3-hexylthiophene) (P3HT) as donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) as acceptor, the power conversion efficiency (PCE) can be improved from 3.71% (with PEDOT:PSS buffer) to 4.27% via introduction of CrOx buffer layer. The PCE of the device based on P3HT as donor and indene-C60-bisadduct (ICBA) as acceptor with CrOx anode buffer layer was further increased from 6.08 (with PEDOT:PSS buffer) to 6.55%. The results indicate that CrOx is a promising anode buffer layer for efficient and stable polymer solar cells.2、We use Niobium oxalate as a new modification layer either of the cathode or the anode to prepare high performance polymer solar cells. Niobium oxalate electron transport layer is a transparent layer of high performance electronic collection, at the same time NbOx hole transport layer is a transparent layer of high performance electron hole collection.Niobium oxalate is applicable to traditional P3HT structure.In AM1.5G,100 mW/cm2 simulated lighting conditions, Niobium oxalate as the anode buffer layer, the properties of the polymer solar cell that base on P3HT:PC60BM system is excellent, the photoelectric conversion efficiency is 4.01%. We use Niobium oxalate as the cathode buffer layer, in AM1.5G,100 mW/cm2 simulated lighting conditions,the photoelectric conversion efficiency of the polymer solar cell that base on P3HT:PC6oBM system is 3.73%. For the polymer solar cell base on P3HT:PC6oBM system that use Niobium oxalate either as the anode buffer layer or the cathode buffer layer, the power conversion efficiency (PCE) is 3.29%.