초록 |
We have investigated the role of buffer layers, titanium oxide (TiOx) and poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS), in inverted polymer solar cells with the structure of indium tin oxide (ITO)/TiOx/P3HT:PCBM/PEDOT:PSS/metal electrode. The TiOx buffer layer as an electron selective layer is closely related with a kink shape of J-V curve. The origin of recovery of the kink shape with UV light illumination was investigated by photoconductivity measurements. In addition, the efficiency and lifetime of the inverted devices were further enhanced by introducing PEDOT:PSS as an anodic buffer layer. The device using PEDOT:PSS showed also the independence of top metal electrodes. |