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) arrays inserted into undoped GaAs barriers have been investigated by using energy dispersive X-ray fluorescence (EDX), transmission electron microscopy (TEM), and photoluminescence (PL) measurements. The EDX pattern, the TEM image, and the selected area electron diffraction pattern showed that self-assembled Si-doped InAs vertically stacked QD arrays were embedded in the GaAs barriers. The temperature-dependent PL spectra showed that the peaks corresponding to the interband transitions of the InAs QDs shifted to the low-energy side with increasing temperature and that the distribution of carriers in the InAs QDs varied with changing temperature. These results indicate that Si-doped InAs QD arrays inserted into GaAs barriers hold promise for potential applications in optoelectronic devices.