Synthesis and optical properties of CsCu2Br3–Cu0 nanoheterojunctions

Abstract

The deliberately fabricated heterojunctions have proved to be able to bring novel functionalities and improved performance for advanced materials. Herein, inspired by the excellent absorption of halide perovskite materials, we report the precisely controlled growth of non-toxic CsCu₂Br₃–Cu⁰ heterojunction nanorods (NRs) through one-pot synthesis. Systematic analyses have shown that Pb²⁺ and Cu²⁺ can be reduced to Pb⁰ and Cu⁺, respectively, by oleylamine at high temperature, while the appearance of Pb⁰ initiates further reduction of Cu⁺ into Cu⁰. The continuous growth of Cu⁰ forms Cu NPs and then matchstick-like CsCu₂Br₃–Cu⁰ heterojunctions. Photoluminescence spectra suggest that the lattice distortion formed at the interface of the CsCu₂Br₃–Cu⁰ heterojunctions leads to the blue-shifting and splitting of the emission peak, which has not been observed previously.