Additive-Free Organic Solar Cells with Power Conversion Efficiency over 10%

摘要

Nowadays, solvent additives are widely used in organic solar cells (OSCs) to tune the nano-morphology of the active blend film and enhance the device performance. With their help, power conversion efficiencies (PCEs) of OSCs have recently stepped over 10%. However, residual additive in the device can induce undesirable morphological change and also accelerate photo-oxidation degradation of the active blend film. Thereby, their involvements are actually unfavorable for practical applications. Here, a donor material PThBDTP is employed, and PThBDTP:PC71BM based OSCs are fabricated. A PCE of over 10% is achieved without using any additives and film post-treatments. The device displays a high open-circuit voltage of 0.977 V, a large short-circuit current density of 13.49 mA cm(-2), and a high fill factor of 76.3%. These results represent an important step towards developing high-efficiency additive-free OSCs.