Synergistic Interactions and Energy Transfer in Cs2ag0.6na0.4in0.8bi0.2cl6:Yb Excited by Blue Light at Room Temperature and Energy Application

Abstract

Lead-free perovskites have attracted attention due to their non-toxicity and high stability. However, the lead-free halide double perovskite Cs2AgInCl6 has difficulty in achieving blue excitation at room temperature, limiting its commercial application. Herein, a rare earth lead-free double perovskite Cs2Ag0.6Na0.4In0.8Bi0.2Cl6:Yb is developed by doping with Yb3+, which exhibits dual emission at 598 nm and 1000 nm in the visible/near-infrared upon blue light excitation at room temperature. The blue light excitation is attributed to the intricate interplay between the energy level splitting induced by Yb3+ ions and the self-trapped exciton (STE) energy level. In addition, under 440 nm excitation, the photoluminescence intensity increases with increasing temperature. A visible/near-infrared light emitting diode was fabricated using a blue light chip. Cs2Ag0.6Na0.4In0.8Bi0.2Cl6:0.5Yb improved the conversion efficiency of GaAs solar cells as a down-shifting layer. Our discovery opens up broad prospects for the development of lead-free double calcium titanium in optoelectronics.

Keywords: Cs2AgInCl6, blue-light excitation, rare earth lead-free double perovskites, Self-trapped exciton, Solar Cell