有机非富勒烯太阳能电池电荷复合及开路电压损失研究

Abstract: The considerable improvement on the power conversion efficiency (PCE) for emerging non-fullerene polymer solar cells is still limited by considerable voltage losses that have become on of the most significant obstacles in further boosting desired photovoltaic performance. Here, I will talk about a comprehensive study to understand the impacts of charge transport, energetic disorder, and charge transfer states (CTS) on the losses in open-circuit voltage (Voc) based on three high performing bulk heterojunction solar cell with the best PCE exceeding 11%. I will introduce a reduction in the non-radiative losses (Vnonrad) coupled with the increase of energy of CTS for the PBDB-T:IT-M device, which may be related to the improved balance in carrier mobilities, and partially can explain the gain in Voc. Our results suggest that minimizing the energetic disorder related to transport and CTS is critical for the mitigation of Voc losses and improvements on the device performance.