OMVPE Grown InAs Quantum Dots for Application in Nanostructured Photovoltaics

we have grown InAs QDs on two types of vicinal GaAs substrates and under various growth conditions. QDs grown on 2deg offcut substrates show superior optical characteristics compared to QDs on 6deg offcut substrates, which showed no QD luminescence. The InAs growth temperature was shown to have an impact on QD nucleation, with higher growth temperature leading to both improved dot densities and coherence. Finally, the V/III ratio during InAs growth dramatically effects the uniformity of the QD luminescence. Our best QDs were grown at 495degC using a V/III ratio of 12. These QDs were 7times40 nm in size with a density of 5(plusmn0.5)times10¹⁰ cm^-2. The spatial PL, peaking at 1220 nm, had a wavelength and intensity deviation across the 2" wafer of 0.3% and 16%, respectively