Stimulated emission from PbS‐quantum dots in glass matrix

The luminescence behavior of PbS‐quantum dots in glass matrix (PbS:Glass) is investigated. Steady‐state and time‐resolved photoluminescence are applied in a wide range of excitation densities up to pulse energies exceeding 50 µJ/cm 2 . While perfect linear recombination is observed across four orders of magnitude, an additional radiative recombination mechanism emerges at an excitation density of 1 µ J/cm 2 per pulse at 390 nm excitation and increases the external quantum efficiency. The time constant of this process is ∼20–40 ps. It is ascribed to stimulated emission. No hint to any non‐linear non‐radiative processes such as Auger recombination is observed. Thermal effects, however, still set limits. This is encouraging news for PbS:Glass as potential laser material.