Ag₂O/PEDOT:PSS used as the anode buffer layer is introduced into the P3HT:PCBM based polymer solar cell (PSC). Effect of the Ag₂O/PEDOT:PSS composite anode buffer layer on the device performance is investigated. According to the results, we can find that the post-thermal annealing can improve the performance of the PSC with Ag₂O/PEDOT:PSS anode buffer layer compare with that without buffer layer. In addition, compared with the devices without such a buffer layer or with only PEDOT:PSS buffer layer, the device with the composite buffer layer can achieve higher J_sc, external quantum efficiency as well as power conversion efficiency. We conclude that the post-thermal annealing can significantly improve the surface morphology which increases the light absorption and the exciton dissociation. The inserted Ag₂O together with PEDOT:PSS as the composite buffer layer not only efficiently lowers the hole extraction barrier and improves the hole collection efficiency but also exhibits excellent stability.

Project supported by the Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20130009130001), the New Century Excellent Talents in University, China (Grant No. NCET-10-0220) and the Fundamental Research Funds for the Central Universities, China (Grant No. 2012JBZ001).