Highly efficient luminescence and color-tunable white emission from 0D Cs2InCl5·H2O perovskites via Al3+ and Sb3+ codoping

Abstract

All-inorganic metal halide perovskites have received extensive attention due to their excellent photoelectric properties. However, addressing toxicity and instability through reasonable doping, as well as improving photoluminescence (PL) efficiency, remains a major challenge. In this study, the introduction of Sb³⁺ alone induces self-trapped excitons (STEs) due to lattice distortion and deformation, producing orange emission (583 nm) and significantly improving luminescence efficiency. When AlCl_x clusters are further introduced, DFT calculations show that Al³⁺ raises energy levels, limiting the energy levels of In and Sb states and producing highly stable individual states. This induces confinement effects and electron–phonon coupling, resulting in blue emission (446 nm) luminescence of STEs. Therefore, Al³⁺ and Sb³⁺ co-doped Cs₂InCl₅·H₂O samples display bright, wideband bimodal emission that covers the entire visible region, with the photoluminescence quantum yield (PLQY) reaching 79.42%. Energy transfer occurs between In–Sb energy levels and singlet–triplet (S–T) transitions. Additionally, varying Al³⁺ concentration under co-doping conditions enables the modulation of luminescence color. High-performance warm white light emitting diodes (WLEDs) with excellent color rendering index and working stability are achieved, promoting the development of lead-free indium-based perovskites for solid-state lighting and displays.