| Organic solar devices have won wide attention from researchers due to the fact that it is low in cost, rich in material resources, easy in producing, flexible in device features and massive in assembling scale. Same to traditional solar devices, the efficiency and life span for organic devices are still restricting their commercializing application. To improve device efficiency even stability, there are many methods, including new material design and device structure engineering. Modifying interface is one of effective device-engineering. It has been reported that proper interface layer can improve efficiency and stability of OPVs by enhancing photo-generated charge carrier extraction from organic active layer to electrodes, modifying the energy level alignment at the interface, protecting active layer from metal diffusion, and/or decreasing the degradation caused by extrinsic oxygen and moisture.This work focuses on the study of optimizing the electrode interface layer with material Zn4O(AID)6 and isoindole derivative, including the following contents:.Firstly, devices based on P3HT:PCBM were investigated with new material Zn4O(AID)6 as the cathode interface layer. Through optimizing thickness of cathode buffer layer, we fond the relationship between thickness of Zn4O(AID)6 and the device efficiency. Compared with the common Li F and Cs2CO3 interface layer, Zn4O(AID)6 is more suitable as an cathode interfacial layer. In order to disclose the reason, the film morphology and electrical properties were studied in detail through AFM, SEM, microscope and impedance spectrum. The result indicated that Zn4O(AID)6 as the cathode interface layer can reduce carrier recombination rate and induce desired vertical phase separation.Secondly, two new isoindole derivative materials HPm I and HPh I were prepared and served as the interface layer in devices based on TAPC:C60 system. However, the results turned out to be unsatisfactory. Phenomena and possible reasons were explored. |
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