Growth and photoluminescence studies of Al-rich AlN∕AlxGa1−xN quantum wells

Abstract

A set of AlN∕AlxGa1−xN (x∼0.65) quantum wells (QWs) with well width Lw varying from 1to3nm has been grown by metal organic chemical vapor deposition. Low temperature photoluminescence (PL) spectroscopy has been employed to study the Lw dependence of the PL spectral peak position, emission efficiency, and linewidth. These results have shown that these AlN∕AlGaN QW structures exhibit polarization fields of ∼4MV∕cm. Due to effects of quantum confinement and polarization fields, AlN∕AlGaN QWs with Lw between 2 and 2.5nm exhibit the highest quantum efficiency. The dependence of the emission linewidth on Lw yielded a linear relationship. The implications of our results on deep ultraviolet optoelectronic device applications are also discussed.