Incorporating Rare-Earth Terbium(III) Ions into Cs2 AgInCl6 :Bi Nanocrystals toward Tunable Photoluminescence.

The incorporation of impurity ions or doping is a promising method for controlling the electronic and optical properties and the structural stability of halide perovskite nanocrystals (NCs). Herein, we establish relationships between rare-earth ions doping and intrinsic emission of lead-free double perovskite Cs2 AgInCl6 NCs to impart and tune the optical performances in the visible light region. Tb3+ ions were incorporated into Cs2 AgInCl6 NCs and occupied In3+ sites as verified by both crystallographic analyses and first-principles calculations. Trace amounts of Bi doping endowed the characteristic emission (5 D4 →7 F6-3 ) of Tb3+ ions with a new excitation peak at 368 nm rather than the single characteristic excitation at 290 nm of Tb3+ . By controlling Tb3+ ions concentration, the emission colors of Bi-doped Cs2 Ag(In1-x Tbx )Cl6 NCs could be continuously tuned from green to orange, through the efficient energy-transfer channel from self-trapped excitons to Tb3+ ions. Our study provides the salient features of the material design of lead-free perovskite NCs and to expand their luminescence applications.