Affiliation:
1. Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, LIFM, GBRCE for Functional Molecular Engineering, School of Chemistry, IGCME Sun Yat‐Sen University Guangzhou 510275 China
Abstract
AbstractLow‐dimensional perovskites afford improved stability against moisture, heat, and ionic migration. However, the low dimensionality typically results in a wide bandgap and strong electron–phonon coupling, which is undesirable for optoelectronic applications. Herein, semiconducting A‐site organic cation engineering by electron‐acceptor bipyridine (bpy) cations (2,2'‐bpy2+ and 4,4'‐bpy2+) is employed to optimize band structure in low‐dimensional perovskites. Benefiting from the merits of lower lowest unoccupied molecular orbital (LUMO) energy for 4,4'‐bpy2+ cation, the corresponding (4,4'‐bpy)PbI4 is endowed with a smaller bandgap (1.44 eV) than the (CH3NH3)PbI3 (1.57 eV) benchmark. Encouragingly, an intramolecular type II band alignment formation between inorganic Pb‐I octahedron anions and bpy2+ cations favors photogenerated electron–hole pairs separation. In addition, a shortening distance between inorganic Pb‐I octahedral chains in (4,4'‐bpy)PbI4 single crystal (SC) can effectively promote carrier transfer. As a result, a self‐powered photodetector based on (4,4'‐bpy)PbI4 SC exhibits 131 folds higher on/off ratio (3807) than the counterpart of (2,2'‐bpy)2Pb3I10 SC (29). The presented result provides an effective strategy for exporting novel organic cation‐based low‐dimensional perovskite SC for high‐performance optoelectronic devices.
Funder
National Natural Science Foundation of China
Basic and Applied Basic Research Foundation of Guangdong Province
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献