Halide perovskite has been widely studied as a new generation of photoelectronic materials. However, their thermal and humidity-induced emission quenching have greatly limited their utility and reliability. Here, we report a hexagonal Mn 2 + -doped CsCdCl 3 perovskite crystal that possesses stable photoluminescence (PL) at both high temperature and humidity. The room temperature long-persistent luminescence (LPL) of the single crystals lasts up to 1480 s and can be adjusted by changing the concentration of Mn 2 + ion doping. The characteristic emission of d-d transition of Mn 2 + is realized, and the photoluminescence quantum yield (PLQY) is up to 91.4 %, it can maintain more than 90 % of the initial PL spectral integral area at 150 °C (423 K). High humid stability PL can be achieved more than 75 % of the initial PL intensity after 55 days of immersion in water. These excellent properties show the application prospect of the LPL material in lighting indication and anti-counterfeiting.

As a non-toxic substitute for lead halide perovskite, layered perovskite has attracted great attention recently. In this work, it is reported that tunable visible light emission properties are given in direct band gap Cs 4 MnBi 2 Cl 12 by doping In 3+ ions. When the Bi 3+ ion is replaced with the In 3+ ion with a relatively small ion radius, it causes distortion of the [MnCl6] 4− octahedron, which changes the local crystal field strength of the Mn 2+ ion, and makes the emission band centered at 606 nm gradually red-shift to 616 nm. By employing Cs 4 MnBi 2 Cl 12 and Cs 4 Mn(Bi 0.88 In 0.12 ) 2 Cl 12 as red-emitting phosphors, LED-1 with Ra = 82 and CCT = 4510 K and LED-2 with Ra = 86 and CCT = 4280 K were obtained, respectively. Compared with Cs 4 MnBi 2 Cl 12 , Cs 4 Mn(Bi 0.88 In 0.12 ) 2 Cl 12 contributes a wider color gamut of 76.4% NTSC for LED devices, than that of 74% NTSC, as R9 increases from 65 to 72. The current work provides a new direction for the regulation of optoelectronic properties in layered double perovskite.

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