10001477_有机非富勒烯太阳能电池电荷复合及开路电压损失研究

有机非富勒烯太阳能电池电荷复合及开路电压损失研究 张旭宁、谢燊坤、张渊 * 北京航空航天大学化学学院 黑格尔北京研究与发展中心 通讯作者张渊，E-mail yuanzhangbuaa.edu.cn 研究方向有机光伏及光电器件、钙钛矿太阳能电池、有机半导体掺杂 论文摘要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 one of the most significant obstacles in further boosting desired photovoltaic performance. Here we report 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. We find that the champion PBDB-TIT-M solar cell PCE 11.5 is associated with the least disorder. The determined energetic disorder in part reconciles the difference in Voc between the solar cells. We observe a reduction in the non-radiative losses ΔVnonrad coupled with the increase of energy of CTS for the PBDB-TIT-M device, which may be related to the improved balance in carrier mobilities, and partially can explain the gain in Voc. The determined radiative limit for Voc combined with the ΔVnonrad generates an excellent agreement for the Voc with the experimental values. 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. 图 1. The increased Voc in a high efficiency OPV with IT-M acceptor with an excellent balance in mobility is associated with reduced energetic disorder at the D/A interface and non-redative recombination losses at charge transfer states. 参考文献 1. S. Xie, Y. Xia, Z. Zheng, X. Zhang, J. Yuan, H. Zhou, Y. Zhang, “Effects of Nonradiative Losses at Charge Transfer States and Energetic Disorder on the Open-Circuit Voltage in Non-Fullerene Organic Solar Cells”, Adv. Funct. Mater. 2018, 28, 1705659. 2. X. Zhang, X. Zuo, S. Xie, J. Yuan, H. Zhou, Y. Zhang, “Understanding charge transport and recombination losses in high performance polymer solar cells with non-fullerene acceptors”, J. Mater. Chem. A 2017, 5, 17230.