Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites

作者：M. Ibrahim Dar, Gwénolé Jacopin, Simone Meloni, Alessandro Mattoni, Neha Arora, Ariadni Boziki, Shaik M. Zakeeruddin, Ursula Röthlisberger, Michaël Grätzel · 发表于：Science Advances · 年份：2016 · DOI：10.1126/sciadv.1601156 · 被引用次数：415 · 研究领域：Perovskite Materials and Applications、Solid-state spectroscopy and crystallography、Luminescence Properties of Advanced Materials

shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices.