Highly Efficient Orange Luminescence in Sn2+-doped Cs2AgInCl6 Double Perovskite with Large Stokes Shift

Abstract

Halide double perovskites (HDPs) show great potential as lead-free alternatives for various optoelectronic devices. However, the device performance depends on HDPs remains significantly below the optimal levels, limiting its applications. In this article, Cs2AgInCl6 emitting orange light is synthesized with anti-solvent method and the optical performance is greatly improved through doping Sn2+ to substitute In3+ due to the enhanced self trapped exciton (STE) emission. The intensity of photoluminescence (PL) is greatly enhanced, the Stokes shift of Cs2AgInCl6:xSn2+ is as large as 360 nm approximately in visible light region, and the full width at half maxima (FWHM) is 270 nm. The Cs2AgInCl6:0.13Sn2+ has the highest photoluminescence quantum yield (PLQY, 29%), which is nearly 15 times higher than Cs2AgInCl6. The lifetime is extended from 3.36 μs to 62.25 μs. Besides, the doped double perovskite exhibits better storage performance than Cs2AgInCl6. The WLED fabricated with Cs2AgInCl6:0.13Sn2+ shows appropriate CCT (4210 K) and high CRI (97). These results provide further insights on the Sn2+ doped Cs2AgInCl6 with large Stokes shift for improving the optical properties and application such as WLED.