Performance Enhancement of Conventional Polymer Solar Cells with TTF-py-Modified PEDOT:PSS Film as the Hole Transport Layer

A thin TTF-py film combined with PEDOT:PSS film was introduced to enhance the device performance of conventional polymer solar cells. The origin of enhanced Jsc and fill factor was systematically studied by SEM, AFM, contact angle and electrochemical impedance spectroscopy measurements. The morphological improvement of TTF-py modified film contributed to the decrease of series loss. In addition, the charge recombination was effectively suppressed as the interfacial contact of modified transport layer with photoactive layer was enhanced as well. Being consistent with the hole mobility test results, the calculated effective carrier mass of TTF-py fitting to the band edge indicates high hole mobility in the organic molecules direction and organic molecules accumulational direction. The results indicate a promising approach by inserting a TTF-py as a modified layer of PEDOT:PSS to promote the performance of conventional polymer solar cells.