CsPbBr₃ Perovskite Quantum Dot Vertical Cavity Lasers with Low Threshold and High Stability

All-inorganic cesium lead bromide (CsPbBr₃) perovskite quantum dots (QDs) have recently emerged as highly promising solution-processed materials for next-generation light-emitting applications. They combine the advantages of QD and perovskite materials, which makes them an attractive platform for achieving high optical gain with high stability. Here, we report an ultralow lasing threshold (0.39 μJ/cm²) from a hybrid vertical cavity surface emitting laser (VCSEL) structure consisting of a CsPbBr₃ QD thin film and two highly reflective distributed Bragg reflectors (DBRs). Temperature dependence of the lasing threshold and long-term stability of the device were also characterized. Notably, the CsPbBr₃ QDs provide superior stability and enable stable device operation over 5 h/1.8 × 10⁷ optical pulse excitations under ambient conditions. This work demonstrates the significant potential of CsPbBr₃ perovskite QD VCSELs for highly reliable lasers, capable of operating in the short-pulse (femtosecond) and quasi-continuous-wave (nanosecond) regimes.