Ultralong Decay Lifetime for CsPbBr3 Perovskite Quantum Dots Glass

Embedding perovskite quantum dots (PeQDs) inside robust glass can address notorious instability issues, but the carrier dynamics in this kind of nanocomposite have not been well understood. In this work, different from the case of colloidal CsPbBr₃ PeQDs, the photoluminescent (PL) decay lifetime of CsPbBr₃@glass experiencing high-temperature crystallization shows a giant elongation from nanoseconds (≈76 ns) to microseconds (≈2 µs). Temperature-dependent time-resolved PL spectra and femtosecond transient absorption (fs-TA) spectra evidence that the defect states within the bandgap acting as carrier trapping centers are responsible for the observed ultralong lifetime. This allows carriers to return to the conduction band via thermal activation from the defect states and participate in radiative recombination. Exploring the mechanisms of ultra-long fluorescence lifetimes in PeQDs@glass will provide deeper insights into their characteristics and offer new strategies for developing novel time-domain optoelectronic applications.