Efficient Energy Transfer in Te4+-Doped Cs2ZrCl6 Vacancy-Ordered Perovskites and Ultrahigh Moisture Stability via A-Site Rb-Alloying Strategy

As an effective method to improve the optical properties and stability of perovskite matrix, doped halide perovskites have attracted extensive attention in the field of optoelectronic applications. Herein, a series of all inorganic lead-free Te4+-doped Cs2ZrCl6 vacancy-ordered perovskites were successfully synthesized with different Te-doping concentrations by a solvothermal method, and deliberate Te4+-doping results in green-yellow triplet self-trapped exciton (STE) emission with a high photoluminescence quantum yield (PLQY) of 49.0%. The efficient energy transfer was observed from singlet to triplet emission. Further, the effects of A-site Rb alloying on the optical properties and stability were investigated. We found that A-site Rb alloying and C-site cohalogenation did not change the luminescence properties of Te4+, but the addition of a small amount of Rb+ can improve the PL intensity and moisture stability. Our results provide physical insights into the nS(2) Te4+-ion-doping-induced emissive mechanism and shed light on improving the environmental stability for further applications.

Automated summary

In this study, a series of all inorganic lead-free Te-doped CsZrCl vacancy-ordered perovskites were successfully synthesized, resulting in green-yellow STE emission with high PLQY. Investigation into the effects of A-site Rb alloying revealed that a small amount of Rb+ can improve the luminescence intensity and moisture stability. The study provides insights into the emissive mechanism induced by Te ion doping and offers potential for improving environmental stability for further applications.