Study of self-assembled InAs quantum dots grown on low temperature GaAs epi-layer

InAs self-organized quantum dots (QDs) grown on annealed low temperature Ga As (LT-GaAs) epi-layer were investigated by transmission electron microscop y (TEM) and photoluminescence (PL) measurement. TEM showed that QDs formed on annealed LT-GaAs epi-layer have a smaller size and a higher density than QDs formed on normal GaAs buffer layer. In addition, the PL spectra analys is showed that the LT-GaAs epi-layer resulted in a blue shift in peak energ y, and a narrower linewidth in the PL peak. The differences were attributed to the point defects and As precipitates in annealed LT-GaAs epi-layer for the point defects and As precipitates change the strain field of the surfa ce. The results provide a method to improve the uniformity and change the e nergy band structure of the QDs by controlling the defects in the LT-GaAs e pi-layer.