Kumar Vikas, Schmidt Whitney L, Schileo Giorgio, Masters Robert C, Wong-Stringer Michael, Sinclair Derek C, Reaney Ian M, Lidzey David, Rodenburg Cornelia
Department of Materials Science and Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, U.K.
Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH, U.K.
ACS Omega. 2017 May 17;2(5):2126-2133. doi: 10.1021/acsomega.7b00265. eCollection 2017 May 31.
Mixed halide (I/Br) complex organic/inorganic hybrid perovskite materials have attracted much attention recently because of their excellent photovoltaic properties. Although it has been proposed that their stability is linked to the chemical inhomogeneity of I/Br, no direct proof has been offered to date. Here, we report a new method, secondary electron hyperspectral imaging (SEHI), which allows direct imaging of the local variation in Br concentration in mixed halide (I/Br) organic/inorganic hybrid perovskites on a nanometric scale. We confirm the presence of a nonuniform Br distribution with variation in concentration within the grain interiors and boundaries and demonstrate how SEHI in conjunction with low-voltage scanning electron microscopy can enhance the understanding of the fundamental physics and materials science of organic/inorganic hybrid photovoltaics, illustrating its potential for research and development in "real-world" applications.
混合卤化物（碘/溴）复合有机/无机杂化钙钛矿材料因其优异的光伏性能最近备受关注。尽管有人提出它们的稳定性与碘/溴的化学不均匀性有关，但迄今为止尚未提供直接证据。在此，我们报告一种新方法，二次电子高光谱成像（SEHI），它能够在纳米尺度上对混合卤化物（碘/溴）有机/无机杂化钙钛矿中溴浓度的局部变化进行直接成像。我们证实了在晶粒内部和边界存在溴分布不均匀且浓度有变化的情况，并展示了SEHI与低电压扫描电子显微镜相结合如何能增进对有机/无机杂化光伏基本物理和材料科学的理解，说明了其在“实际”应用中的研发潜力。
