STRUCTURAL AND OPTICAL PROPERTIES OF SELF-ASSEMBLED InAs QUANTUM DOTS GROWN ON GaAs(311) A SUBSTRATE
GaAs(311)A衬底上自组装InAs量子点的结构和光学特性

We report the structural and optical characteristics of InAs quantum dots (QDs) grown on GaAs (311)A substrates. Atomic force microscopic result shows that QDs on (311)A surface exhibit a nonconventional, faceted, arrowhead-like shapes aligned in the 233] direction. The photolumi-nescence (PL) intensity, peak position and the full width at half maxinum (FWHM) are all colsely related to the measurement temperature. The fast redshift of PL energy and monotonous decrease of linewidth with increasing temperature were observed and explained by carriers being thermally activated to the barrier produced by the wetting layer and then being retrapped and recombined in energetically lower-lying QDs states. This model explains our results well.