Effective Energy Transfer Boosts Emission of Rare-Earth Double Perovskites: The Bridge Role of Sb(III) Doping

Halide perovskites have attracted considerable interestdue totheir excellent photoelectric properties. In this study, we synthesizedSb(3+)-doped Cs2NaTbCl6 using a solvothermalmethod to investigate its tunable photoelectric properties and lowtoxicity. Upon Sb3+ ion doping, the photoluminescence yield(PLQY) of Cs2NaTbCl6 significantly increasedfrom & SIM;1.7 to & SIM;47%. The introduced Sb3+ ionswith ns(2) electronic configuration expanded the rare-earthelement's absorption cross section, broke intrinsic forbiddentransitions, and suppressed nonradiative recombination. Additionally,the codoping of Sb3+ and Mn2+ facilitated efficientenergy transfer, resulting in highly efficient photoluminescence.The PLQY of 1%Sb3+,3%Mn2+:Cs2NaTbCl6 reached a remarkable 85.8%, marking the highest reportedvalue for rare-earth double perovskites in the visible light region.This study highlights the vital role of Sb(III) doping as a bridgingagent to enhance the emission in rare-earth double perovskites.