INTERMIXING INDUCED CHANGES IN THE RADIATIVE EMISSION FROM III-V QUANTUM DOTS

We have examined the effect of thermally induced interdiffusion on the luminescence emission from red and infrared emitting self-assembled I II-V quantum dots. Three different combinations of dot/barrier materia ls have been investigated: InAlAs/AlGaAs, InGaAs/AlGaAs and InGaAs/GaA s. In all cases, thermal intermixing was found to result in significan t blueshifts of the photoluminescence (PL) emission. in addition, narr owing of the linewidth of the inhomogeneously broadened PL peak was ob served, Both effects were found to be strongly dependent on the materi al system and average dot size. InAlAs/AlGaAs quantum dots exhibited t he greatest linewidth reduction after intermixing, indicating this to be a promising method of achieving narrower luminescence lines for dev ices such as red-emitting zero-dimensional lasers. (C) 1998 American I nstitute of Physics.