Wang Yanyan, Wen Rui, Liu Yuanyuan, Bi Le-Yu, Yang Mingming, Sun Huaming, Zheng Yan-Zhen, Zhang Guofang, Gao Ziwei
Key Laboratory of Applied Surface and Colloid Chemistry MOE, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China.
Frontier Institute of Science and Technology (FIST), State Key Laboratory of Mechanical Behavior for Materials, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter and School of Science, Xi'an Jiaotong University, Xi'an, 710054, P. R. China.
ChemSusChem. 2020 May 22;13(10):2753-2760. doi: 10.1002/cssc.202000282. Epub 2020 Apr 6.
Bismuth organometal halide perovskites have recently been investigated as potential substitutes for lead perovskite solar-cell absorbers because of their lower toxicity. However, the narrowing of the band gap remains a crucial challenge for their practical application. All known Bi-based perovskites have large band gaps, thereby affording weak visible-light absorption. This study concerns a novel, lead-free, pseudo-3 D perovskite optoelectronic material, (MV)BiI (MV =methyl viologen). The pseudo-3 D metal-halogen perovskite-like structure is constructed by connecting [BiI ] units via I⋅⋅⋅I contacts. MV, as a rigid organic amine, is located at the center of each parallelepiped to balance the charge and stabilize the structure. (MV)BiI has a narrow band gap of 1.48 eV and a better photoresponse than (MV)BiCl with a 1 D structure. (MV)BiI is the first Bi-based perovskite compound with a band gap energy comparable with (CH NH )PbI , which is encouraging for optoelectronic applications. This research will open a potential pathway for the design of pseudo-3 D Bi-based perovskites with performances comparable with APbX absorbers.
由于铋有机金属卤化物钙钛矿毒性较低，近来被作为铅钙钛矿太阳能电池吸收层的潜在替代物进行研究。然而，对于其实际应用而言，带隙变窄仍然是一个关键挑战。所有已知的铋基钙钛矿都具有较大的带隙，因此可见光吸收较弱。本研究涉及一种新型的无铅准三维钙钛矿光电子材料（MV）BiI₅（MV = 甲基紫精）。这种准三维金属卤化物类钙钛矿结构是通过I⋅⋅⋅I接触连接[BiI₆]³⁻单元构建而成。MV作为一种刚性有机胺，位于每个平行六面体的中心以平衡电荷并稳定结构。（MV）BiI₅具有1.48 eV的窄带隙，并且与具有一维结构的（MV）BiCl相比具有更好的光响应。（MV）BiI₅是第一种带隙能量与（CH₃NH₃）PbI₃相当的铋基钙钛矿化合物，这对于光电子应用来说是令人鼓舞的。该研究将为设计性能与APbX吸收层相当的准三维铋基钙钛矿开辟一条潜在途径。
