Mixed-metal thiophosphate CuCd3PS6: an infrared nonlinear optical material activated by its three-in-one tetrahedra-stacking architecture

Novel mixed-metal thiophosphate CuCd3PS6 has been firstly discovered and fully characterized. Careful experimental and theoretical investigations demonstrate that CuCd3PS6 is a benign infrared nonlinear optical material with a moderate second harmonic generation response of 0.9 × AgGaS2 at 41–74 μm, a large laser damage threshold of 4.1 × AgGaS2, a wide band gap of 2.24 eV and a low melting point of 603 °C. Moreover, first principles calculations indicate that CuCd3PS6's intriguing nonlinear optical performance is activated by its three-in-one tetrahedra-stacking architecture.