Sb3+/Mn2+ co-doped lead-free Cs2KYCl6 perovskites for white light-emitting diodes

Abstract

Lead-free halide perovskites have been developed and have received increasing attention in optoelectronic applications due to their non-toxicity. However, single perovskite phosphors that emit vibrant, tunable-color-temperature white-light are rare. Herein, we used the anti-solvent precipitation method to develop white light-emitting diodes (WLEDs) based on rare-earth-based Sb³⁺ and Mn²⁺ co-doped Cs₂KYCl₆ microcrystals (MCs). The Cs₂KYCl₆ MCs exhibit tunable dual emissions covering a wideband ascribed to the emission of self-trapped excitons (STEs) from Sb³⁺ and the ⁴T₁ to ⁶A₁d–d transition of Mn²⁺. The optimal photoluminescence quantum yield (PLQY) of doped Cs₂KYCl₆ is 65.78%. The energy transfer process from Sb³⁺ to Mn²⁺ is revealed. WLEDs have been successfully constructed by combining the dual emissions from STEs of Sb³⁺ and the d–d transition of Mn²⁺. These WLEDs demonstrate impressive optical performance, including CIE chromaticity coordinates (0.3483, 0.4125) and a color rendering index (CRI) of 85.4. This work provides an effective strategy for developing WLEDs based on a single-component material, lead-free perovskites.