To attain commercial viability, perovskite solar cells (PSCs) have to be reasonably priced, highly efficient, and stable for a long period of time. Although a new record of a certified power conversion efficiency (PCE) value over 25% was achieved, PSC performance is limited by the lack of hole-transporting materials (HTMs), which extract positive charges from the light-absorbing perovskite layer and carry them to the electrode. Here, we report spirobifluorene-based HTMs with finely tuned energy levels, high glass-transition temperature, and excellent charge mobility and conductivity enabled by molecularly engineered enamine arms. HTMs are synthesized using simple condensation chemistry, which does not require costly catalysts, inert reaction conditions, and time-consuming product purification procedures. Enamine-derived HTMs allow the fabrication of PSCs reaching a maximum PCE of 19.2% and stability comparable to spiro-OMeTAD. This work demonstrates that simple enamine condensation reactions could be used as a universal path to obtain HTMs for highly efficient and stable PSCs.
要实现商业可行性,过氧化物太阳能电池(PSC)必须价格合理、效率高且长期稳定。虽然目前已创下功率转换效率(PCE)超过 25% 的新纪录,但由于缺乏空穴传输材料(HTM),PSC 的性能受到了限制,而空穴传输材料能从吸光的包晶层中提取正电荷并将其传输到电极。在这里,我们报告了基于螺二
芴的 HTMs,这些 HTMs 能级经过微调,具有较高的
玻璃跃迁温度,并通过分子工程烯胺臂实现了出色的电荷迁移率和电导率。HTMs 采用简单的缩合
化学反应合成,无需昂贵的催化剂、惰性反应条件和耗时的产品纯化程序。烯胺衍生 HTM 可以制造出最大 PCE 为 19.2% 的 PSC,其稳定性可媲美螺-OMeTAD。这项研究表明,简单的烯胺缩合反应可作为获得 HTMs 的通用途径,从而制备出高效稳定的 PSCs。