Synthesis and optical properties of CsCuBr-Cu nanoheterojunctions

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 CsCu 2 Br 3 -Cu 0 heterojunction nanorods (NRs) through one-pot synthesis. Systematic analyses have shown that Pb 2+ and Cu 2+ can be reduced to Pb 0 and Cu + , respectively, by oleylamine at high temperature, while the appearance of Pb 0 initiates further reduction of Cu + into Cu 0 . The continuous growth of Cu 0 forms Cu NPs and then matchstick-like CsCu 2 Br 3 -Cu 0 heterojunctions. Photoluminescence spectra suggest that the lattice distortion formed at the interface of the CsCu 2 Br 3 -Cu 0 heterojunctions leads to the blue-shifting and splitting of the emission peak, which has not been observed previously. During the synthesis of CsCu 2 Br 3 quantum dots, the post-introduced Pb 2+ is reduced by oleylamine to Pb 0 , which initiates the further reduction of Cu + to Cu 0 , and the growth of Cu 0 NPs finally leads to the formation of CsCu 2 Br 3 -Cu 0 nanoheterojunctions.