A two-step method combining electrodepositing and spin-coating for solar cell processing

Electrochemistry provides a simple and promising method for preparing organic solar cells (OSCs). In this paper, we present a two-step solution-based method to prepare bilayer heterojunction OSCs by electrodepositing polythiophene (PTh) and then spin-coating chloroform solution of [6,6]-phenyl C61-butyric acid methyl ester (PCBM) onto the PTh layer. The influence of film thickness on performance of bilayer solar cells was investigated, and the best performance was achieved when the thickness of PTh and PCBM was 15 nm and 30 nm, respectively. The optimized solar cell showed power conversion efficiency of 0.1% under the illumination of AM 1.5 (100 mW cm−2) simulated solar light. This solution-based method offers a new way for processing bilayer OSCs.