Stable zero-dimensional cesium indium bromide hollow nanocrystals emitting blue light from self-trapped excitons

The growing demand for lighting and displays has motivated intensive research in metal-halide perovskite nanocrystals (NCs) recently. However, the development of blue-emissive perovskite NCs lag behind those of green and red ones severely; moreover, the conventional lead-halide perovskites contain toxic element lead. In this study, zero-dimensional Cs3InBr6 NCs with intrinsic broadband blue emission (similar to 450 nm) were developed for the first time. Joint experiment-theory characterizations reveal the excited-state structural distortion of [InBr6](3-) cluster enables the formation of self-trapped excitons, which contribute the broadband emission. Apart from the solid structure, hollow NCs with controlled particle and pore sizes were obtained resulting from the Ostwald ripening mechanisms. Theoretical calculations show that the easy diffusion of Br vacancies in Cs3InBr6 lattices assist the formation of hollow structure. Encouraged by the remarkable structural and optical stability of hollow Cs3InBr6 NCs, such lead-free NCs may open up new avenues for manufacture of optoelectronic devices. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study developed zero-dimensional Cs3InBr6 NCs with intrinsic broadband blue emission, revealing that the excited-state structural distortion enables the formation of self-trapped excitons and hollow NCs with controlled sizes. The remarkable structural and optical stability of Cs3InBr6 NCs may open up new avenues for manufacturing optoelectronic devices.