Improved performances of CuPc/C60-based solar cell by using randomly and irregularly embossed PEDOT:PSS as anode buffer layer

An unique organic solar cell (OSC) based on copper phthalocyanine (CuPc) and fullerene C60 as the electron donor and acceptor materials is demonstrated with randomly and irregularly embossed poly (3, 4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT: PSS) as anode buffer layer. The effect of PEDOT:PSS nanostructure is characterized by optical and electrical measurements. The results indicate that introducing irregular nanostructure with random distribution into OSC leads to longer light paths by efficient scattering of the incident light and thus higher light absorption in active layer. Moreover, such a nanostructure increases the junction area, allowing more efficient exciton dissociation and charge carrier transfer/collection. These combined effects result in a prominent enhancement of 25.5% in average power conversion efficiency relative to the non-structured OSC due to the increases in short-circuit current and fill factor.