Zero-dimensional organic-inorganic hybrid cuprous halide of (C20H20OP)CuCl2 with high anti-water stability

Recently, copper(I)-based metal halides have gained increasing attention due to their diverse structures and desirable optoelectronic properties. Herein, we report a novel zero-dimensional (0D) Cu-based halide (C20H20OP)CuCl2 [C20H20OP+ = (Methoxymethyl)triphenylphosphonium chloride cation], single crystals (SCs) of which were synthesized by a simple solution growth method. The bulk assembly of the periodic 0D structure is formed by the organic cation [C20H20OP]+ surrounding isolated [CuCl2]- units. The (C20H20OP)CuCl2 single crystals emit broadband yellow light upon UV excitation. Similarity to hybrid Br−/I− based copper compounds, as-synthesized compound displays remarkable resistance to water, maintaining its photoluminescence (PL) intensity at over 94% even after being immersed in water for 24 h. This work demonstrates the potential of constructing luminescent materials with high water resistance, which will pave the way for a new approach to developing water-resistant materials based on lead-free metal halides.