CsPbBr3 and Cs4PbBr6-CsPbBr3 composite perovskite sensitization of 3D-ZnO nanostructures for enhanced photoluminescence emission

This study reports a seeding-layer free synthesis of nanostructured three-dimensional zinc oxide (3D-ZnO) thin films via a simple and cost-effective chemical bath deposition method (CBD) followed by their sensitization with inorganic perovskite halide semiconductors for luminescence-based applications. The emission abilities of pristine ZnO nanostructures have been enhanced with the incorporation of CsPbBr3 in the cubic crystal phase, which is proven to be a highly stable member of the inorganic halide perovskite family. Additionally, the transformation of CsPbBr3 nanocrystals into Cs4PbBr6-CsPbBr3 composite structure has been attained by altering the (i) CsBr content and (ii) crystallization temperature during the perovskite synthesis step, resulting in a remarkable luminescence increase for the overall structure by -17 folds. A detailed evaluation of defect contents and carrier lifetimes of pristine and perovskite deposited ZnO thin films have been conducted via time-resolved photoluminescence spectroscopy showing an improved electron transfer especially for Cs4PbBr6-CsPbBr3 deposited ZnO thin films.