THERMAL-STABILITY OF VERTICALLY COUPLED INAS-GAAS QUANTUM-DOT ARRAYS

The effect of high-temperature annealing on the optical properties of vertically coupled InAs quantum dots in a GaAs matrix and on the perfo rmance of a quantum-dot laser are studied. A strong blue shift of the photoluminescence peak and lasing line, as well as changes in the phot oluminescence intensity and temperature dependence of the threshold cu rrent density are observed. The reason for this behavior is probably a reduction in the carrier localization energy due to a partial mixing of the In and Ga atoms as well as an improvement in the quality of the low-temperature grown Ga(Al)As layers achieved by high-temperature an nealing. (C) 1997 American Institute of Physics.