Glass stabilized ultra-stable dual-emitting Mn-doped cesium lead halide perovskite quantum dots for cryogenic temperature sensing

Abstract

Mn-Doped CsPb(Cl/Br)₃ quantum dots possess multi-functional optical, electronic and magnetic characteristics. However, they usually suffer from decomposition in air, and Mn²⁺ dopants will be gradually expelled from the perovskite host due to a radius mismatch between Pb²⁺ and Mn²⁺. To solve these crucial issues, the synthesis of glass stabilized Mn-doped quantum dots via an appropriate glass composition design and in situ glass crystallization is reported. Mn²⁺ dopants act as nucleating agents to promote the nucleation/growth of CsPb(Cl/Br)₃ from B–P–Zn–Cs–Pb based oxyhalide glass and partition into the perovskite host to produce dual-color luminescence via efficient exciton-to-dopant energy transfer. Benefitting from the effective protection of robust glass, Mn-doped CsPb(Cl/Br)₃ quantum dots exhibit superior water resistance and thermal stability. Particularly, almost 100% luminescence is retained after immersing the composite in water for 30 days. Interestingly, rapid thermal quenching for exciton recombination relative to Mn²⁺ d–d transition at cryogenic temperatures enables its promising applications as a ratiometric temperature sensing medium.