All-Inorganic Lead-Free 0D Perovskites by a Doping Strategy to Achieve a PLQY Boost from <2 % to 90

Abstract

Zero-dimensional (0D) lead-free perovskites have unique structures and optoelectronic properties. Undoped and Sb-doped all inorganic, lead-free, 0D perovskite single crystals A₂ InCl₅ (H₂ O) (A=Rb, Cs) are presented that exhibit greatly enhanced yellow emission. To study the effect of coordination H₂ O, Sb-doped A₃ InCl₆ (A=Rb, Cs) are also synthesized and further studied. The photoluminescence (PL) color changes from yellow to green emission. Interestingly, the photoluminescence quantum yield (PLQY) realizes a great boost from <2 % to 85-95 % through doping Sb³⁺ . We further explore the effect of Sb³⁺ dopants and the origin of bright emission by ultrafast transient absorption techniques. Furthermore, Sb-doped 0D rubidium indium chloride perovskites show excellent stability. These findings not only provide a way to design a set of new high-performance 0D lead-free perovskites, but also reveal the relationship between structure and PL properties.

Keywords: doping; enhanced photoluminescence; lead-free perovskites; stability; zero-dimensional perovskites.