Optical properties of the ${\mathrm{Pb}}^{2+}$-based aggregated phase in a CsCl host crystal: Quantum-confinement effects

The quantum-confinement effect is demonstrated in the luminescence of the ${\mathrm{CsPbCl}}_3$-like aggregated phase in ${\mathrm{Pb}}^{2+}$-doped CsCl single crystals. Namely, microscopic excitonic superradiance is considered to explain the observed picosecond decay kinetics of the aggregated-phase emission band at 420 mn. The low- and high-temperature limits of the temperature dependence of the radiative decay time in the quantum dot are derived and compared with experimental data. Different processes that might influence the observed wavelength and temperature dependence of the observed decay time are discussed.