Harnessing strong aromatic conjugation in low-dimensional perovskite heterojunctions for high-performance photovoltaic devices
Bo Li, Qi Liu, Jianqiu Gong, Shuai Li, Chunlei Zhang, Danpeng Gao, Zhongwei Chen, Zhen Li, Xin Wu, Dan Zhao, Zexin Yu, Xintong Li, Yan Wang, Haipeng Lu, Xiao Cheng Zeng, Zonglong Zhu
Abstract
Abstract Low-dimensional/three-dimensional perovskite heterojunctions have shown great potential for improving the performance of perovskite photovoltaics, but large organic cations in low-dimensional perovskites hinder charge transport and cause carrier mobility anisotropy at the heterojunction interface. Here, we report a low-dimensional/three-dimensional perovskite heterojunction that introduces strong aromatic conjugated low-dimensional perovskites in p-i-n devices to reduce the electron transport resistance crossing the perovskite/electron extraction interface. The strong aromatic conjugated π-conjugated network results in continuous energy orbits among [Pb 2 I 6 ] 2− frameworks, thereby effectively suppressing interfacial non-radiative recombination and boosting carrier extraction. Consequently, the devices achieved an improved efficiency to 25.66% (certified 25.20%), and maintained over 95% of the initial efficiency after 1200 hours and 1000 hours under ISOS-L-1I and ISOS-D-1 protocols, respectively. The chemical design of strong aromatic conjugated molecules in perovskite heterojunctions provides a promising avenue for developing efficient and stable perovskite photovoltaics.