Growth of large Cs2Cu(Cl, Br)4 single crystals

Abstract

In this work, copper-based halides Cs₂CuCl₄, Cs₂CuBr₄ and mixed-halides Cs₂CuCl_2.8Br_1.2, Cs₂CuCl₂Br₂ and Cs₂CuCl_1.2Br_2.8 single crystals were grown via the evaporation method using deionized water as a solvent. The structure and actual element component of the Cs₂Cu(Cl, Br)₄ crystals were studied using XRD and EDS. The halides of Cs₂Cu(Cl, Br)₄ exhibit both good light absorption and PL performance. The absorption peaks related to LMCT electron transition bands were observed, and the tunable band gap was obtained by adjusting the Br⁻/Cl⁻ ratio. PL spectra show purple, blue, and green luminescence, and the luminescence mechanism was analyzed. Our study indicates that the Cs₂Cu(Cl, Br)₄ halides have application prospects in optoelectronic devices.