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arXiv · 1411.7606

Self-regulation mechanism for charged point defects in hybrid halide perovskites

Aron Walsh·David O. Scanlon·Shiyou Chen·Xingao Gong·Su-Huai Wei
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Abstract

Hybrid halide perovskites such as methylammonium lead iodide (CH3NH3PbI3) exhibit unusually low free carrier concentrations despite being processed at low-temperatures from solution. We demonstrate, through quantum mechanical calculations, that the origin of this phenomenon is a prevalence of ionic over electronic disorder in stoichiometric materials. Schottky defect formation provides a mechanism to self-regulate the concentration of charge carriers through ionic compensation of charged point defects. The equilibrium charged vacancy concentration is predicted to exceed 0.4% at room temperature. This behaviour, which goes against established defect conventions for inorganic semiconductors, has implications for photovoltaic performance.

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Aron Walsh, David O. Scanlon, Shiyou Chen, Xingao Gong, Su-Huai Wei. 2014-11-27. Self-regulation mechanism for charged point defects in hybrid halide perovskites. https://doi.org/10.1002/anie.201409740

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