In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs2SnCl6 double perovskite crystals were prepared by aqueous phase precipitation method using SnCl2 as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce3+-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [ S n S n 4 + 2 + +VCl] defect complex in the crystal is formed by Sn2+ substituting Sn4+. The number of defects formed by Sn2+ in the crystal decreases with Ce3+ content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [ S n S n 4 + 2 + +VCl] decreased. When Ce3+ is incorporated into the crystals, the defects of [ C e 3 + S n 4 + +VCl] and [ S n S n 4 + 2 + +VCl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs2SnCl6 double perovskite crystals.

A new red phosphor, Ba(2)Mg(BO(3))(2):Eu,Mn, was synthesized by the solid-state reaction method and its photoluminescence properties were investigated by excitation and emission spectra and decay curves. Its excitation band is extending from 250-450 nm, which is adaptable to the emission band of near-ultraviolet LED chips (350-420 nm). Upon the excitation of 365 nm light, the phosphor exhibits strong red emission centered at 615 nm. The relationship between Eu(2+) and Mn(2+) dopants was studied from the viewpoint of a crystal structure and by photoluminescence spectra and decay curves. The results show that the characteristic Eu(2+) emission predominate in the emission band and Mn(2+) promote the redistribution of Eu(2+) at the cation sites of the host crystal.

No abstract

Eu2+‐doped SrCN2 with different Eu2+ contents were prepared by a high‐temperature solid‐state reaction under NH3 atmosphere. SrCN2 has an energy gap of 4.56 eV by the reflection spectra. The photoluminescence spectra of SrCN2:Eu2+ at different temperatures were measured. The results show that Eu2+‐doped SrCN2 shows a broad band emission with a peak at 610 nm when it is excited by 350–520 nm at 77 K. With the temperature increasing, the emission intensity decreases remarkably, indicating that Eu2+‐doped SrCN2 has a low quenching temperature.