Investigating energy transfer in lanthanide-doped double perovskites exhibiting visible and near-infrared emission†

Abstract

The integration of lanthanide ions (Ln³⁺) into halide double perovskites has emerged as a promising approach to tailor their optical and electronic properties for optoelectronic applications. In this study, an Sb³⁺–Tm³⁺ co-doped Cs₂NaInCl₆ double perovskite was synthesized via a simple hydrothermal method. The prepared Cs₂NaInCl₆:Sb³⁺–Tm³⁺ exhibits a single-crystal octahedral structure and achieves an optimal NIR photoluminescence quantum yield of 20%. The co-doping strategy with Sb³⁺ and Tm³⁺ facilitates energy transfer from Sb³⁺ to Tm³⁺, leading to the appearance of an NIR emission peak at 1220 nm. Temperature-dependent (80 to 300 K) photoluminescence measurements elucidate the excitation and emission mechanisms. Through the deposition of the perovskite on a commercial 365 nm LED chip, a pc-LED was engineered to be capable of producing both visible light and NIR emissions.