Vacuum-Vapor-Deposited 0D/3D All-Inorganic Perovskite Composite Films toward Low-Threshold Amplified Spontaneous Emission and Lasing.

Vacuum vapor deposition (VVD) is a promising way to advancing the commercialization of perovskite light sources owing to its convenience for wafer-scale mass production and compatibility with silicon photonics manufacturing infrastructure. However, the light emission performance of VVD-grown perovskites still lags far behind that of the conventional solution-processed counterparts due to their inferior luminescence properties. Here, a 0D/3D cesium-lead-bromide perovskite composite film is prepared on Si/SiO 2 substrates through composition modulation with the VVD method, which exhibits an ultralow amplified spontaneous emission (ASE) threshold down to 14.3 µJ cm -2 in the optimal films, which is on par with that of the solution-processed counterparts. Meanwhile, they also display intriguing operational stability with negligible emission intensity decay under continuous excitation above ASE threshold for 4 h in the air. The outstanding ASE performance mainly originates from the reduced trap density and weakened electron-phonon coupling in the 3D CsPbBr 3 phase enabled by the incorporation of the 0D Cs 4 PbBr 6 phase. Finally, by integrating the composite film with the distributed feedback (DFB) cavity, DFB lasing is achieved with a low threshold of 18.2 µJ cm -2 under nanosecond-pulsed laser pumping, which highlights the potential of VVD-processed perovskites for developing high-performance lasers.