“…All-inorganic lead halide perovskites (LHPs) CsPbX 3 (X = Br, Cl, I) have attracted enormous research interest recently owing to their excellent physical and optoelectronic properties originating from their direct optical band gap, 1 large optical absorption coefficient, 2,3 long-range diffusion length, 4 high charge carrier mobility, 5 high photoluminescence quantum yield (PLQY), 6 narrow photoluminescence (PL) linewidth, 7 and wide colour gamut. 1–5 These interesting properties bring great potentiality 8–11 towards various optoelectronic applications like photovoltaics, 12,13 light-emitting diodes, 14–16 single-photon sources, 17–19 X-ray scintillators, 20 and lasers. 21 However, the sensitivity of LHPs to oxygen and moisture is an obstacle for realistic applications.…”