Organic cation directed one-dimensional cuprous halide compounds: syntheses, crystal structures and photoluminescence properties

Abstract

In recent years, organic–inorganic hybrid metal halides have emerged as a highly promising class of semiconducting light emitting diodes (LEDs) due to their fascinating photoluminescence properties. Here, by specifically selecting different organic cations as templates, a series of new hybrid cuprous halides have been solvothermally prepared, namely [Me-Py]CuI₂ (1), [(Me)₂-DABCO]Cu₂I₄ (2), [Me-MePy]Cu₂I₃ (3), and [H₂DABCO]Cu₃X₅ (X = I (4) and Br (5)). These hybrid cuprous halides feature one-dimensional (1D) [CuI₂]⁻, [Cu₂I₃]⁻ and [Cu₃X₅]²⁻ (X = Br, I) chains surrounded and charge-balanced by organic cations. Under UV photoexcitation, these hybrid cuprous halides exhibit strong tunable photoluminescence from cyan (480 nm) to red (675 nm) emissions with large Stokes shifts (345 nm). The intrinsic nature of PL emissions is also investigated based on temperature-dependent PL emission, lifetime, photoluminescence quantum efficiencies, etc.