Water Resistance and Flexible Cuprous Halide Composite Polysiloxane Luminescent Ceramics

Copper(I) halides (Cu(I)Hs) have attracted extensive attention for their excellent luminescent properties. However, their poor water stability seriously hinders their application. So far, research on the performance improvement has been rarely reported. In this paper, a cuprous halide composite (Cu(I)HC) containing CsCu2Cl2I, CsCu2ClI2, and CuI phases was synthesized and presented. Under 285 nm ultraviolet light irradiation, CsCu2ClI2 in Cu(I)HC showed an abnormal photoluminescence for CsCu2X3 (X = Cl, Br, I), which generates a blue sky emission with the wavelength of 475 nm and the full width at half maximum of 99 nm, showing a typical self-trapped exciton emission. The Cu(I)HC can also give near white and violet emission following the excitation wavelength from 250 to 360 nm. It is exciting that the water stability of Cu(I)HC underwent a qualitative leap when it was coated with polysiloxane. Near white light emission Cu(I)HC polysiloxane luminescent ceramics (PSOLCs) were prepared for WLED exploration. Our method not only enhanced the water resistance of solvent-sensitive Cu(I)Hs, but also endowed them with the property of flexibility, which greatly expands their application fields. The prepared PSOLCs have potential applications in optical information encryption, lighting, and flexible photoelectron.