Microstructural and interband transition studies of multiple stacked layers of Si-doped InAs self-assembled quantum dot arrays inserted into GaAs barriers

Microstructural and optical properties of Si-doped InAs quantum dot (QD) ar rays inserted into undoped GaAs barriers have been investigated by using en ergy dispersive X-ray fluorescence (EDX), transmission electron microscopy (TEM), and photoluminescence (PL) measurements. The EDX pattern, the TEM im age, and the selected area electron diffraction pattern showed that self-as sembled Si-doped InAs vertically stacked QD arrays were embedded in the GaA s barriers. The temperature-dependent PL spectra showed that the peaks corr esponding to the interband transitions of the InAs QDs shifted to the low-e nergy side with increasing temperature and that the distribution of carrier s in the InAs QDs varied with changing temperature. These results indicate that Si-doped InAs QD arrays inserted into GaAs barriers hold promise for p otential applications in optoelectronic devices. (C) 2001 Elsevier Science Ltd. All rights reserved.