Luminescence properties of multi-layer InGaN quantum dots grown on C- and R-plane sapphire substrates

In this study, we report comparative luminescence properties of multi-layer InGaN quantum dots grown on C- and R-plane sapphire substrates by metal organic chemical vapor deposition (MOCVD). High-density InGaN quantum dots (QDs) are formed on GaN templates by decreasing the growth temperature and increasing the adatom hopping-barrier through surface passivation. Atomic force microscopy (AFM) has been employed to estimate the size and height of these dots. Photoluminescence (PL) spectra recorded from View the MathML source InGaN QDs/View the MathML source sapphire show much stronger emission intensity compared to spectra recorded from (0 0 0 1) InGaN QDs/(0 0 0 1) sapphire. Due to the absence of strong spontaneous polarization and piezoelectric field, such View the MathML source InGaN QDs in the active layers would lead to high efficiency light emitting devices.