Optical Properties of Cu-Doped Perovskite Nanoplatelets

Abstract

All inorganic perovskite nanocrystals (NCs) have been widely concerned for their unique optical properties. However, due to the rotation and inclining of the [PbX6]4− octahedron caused by Cs ions, such kind of materials usually have poor stability, which will hinder their commercialization. It is well known that using smaller divalent cations to replace Pb2+ can effectively improve the stability and luminescence properties of CsPbX3 NCs. In this work, Cu-doped CsPbBr3 nanoplatelets (NPs) are prepared, i.e., CsPb0.95Cu0.05Br3 NPs, and their temperature dependent emission properties have been investigated. The experimental results show that Cu-doping method can weaken the thermal expansion effect and electron-phonon interaction strength of perovskite NPs. Although the exciton binding energy of CsPb0.95Cu0.05Br3 NPs is smaller than that of CsPbBr3 NPs, it is still much larger than that of CsPbBr3 cubic NCs. Our experimental results will be of significance for the development of optoelectronic devices based on transition metal doped perovskite NPs.