PHOTOLUMINESCENCE OF MULTI LAYER GaSb/GaAs SELF-ASSEMBLED QUANTUM DOTS GROWN BY METAL ORGANIC CHEMICAL VAPOR DEPOSITION AT ATMOSPHERIC PRESSURE

We investigate photoluminescence from multilayer GaSb self-assembled quantum dots embedded in GaAs grown by metalorganic chemical vapor deposition. The spectra show the emission from quantum dots at about 1.09 eV and from the wetting layer at 1.39 eV. With increasing temperature the wetting layer emission quenches faster than the quantum dot emission. We also observe a decrease of the quantum dot peak energy at temperatures between 50 and 70 K and a peak shift with increasing excitation powers typical of type II structures. A large separation (300 meV) between the photoluminescence peaks from quantum dots and the wetting layer suggests differences in the intermixing at the GaSb/GaAs interface in the structures grown by metalorganic chemical vapor deposition and by molecular-beam epitaxy.