Photoluminescence from InAs quantum dots on GaAs(100)

Abstract

Several samples of self-organized InAs quantum dots (QDs) with different InAs deposition and an InGaAs quantum well on GaAs(100) were grown by Molecular Beam Epitaxy (MBE). The photoluminescence (PL) of QDs was measured in the temperature range from 79 K to room temperature. The temperature dependence of the PL peak energy is roughly the same as that of InGaAs quantum wells and attributed to the temperature dependence of the band gap. The ratio of PL peak intensity from QDs to that from wetting layer increases with the increase of InAs deposition. It is attributed to the increase in QDs density and more photocarriers transfer from wetting layer to QD. In the case of small InAs deposition, the PL intensity from QDs increases with temperature increase in a certain temperature range. It is also due to the carrier transfer from wetting layer to QDs. The full width at half maximum (FWHM) of the QDs decreases with temperature in a certain temperature range. This is attributed to the photocarrier transfer from small QDs to large ones by tunneling.