AlxGa1 - xN alloys with x up to 0.7 were grown by metalorganic chemical vapor deposition and their optical properties were investigated by deep UV time-resolved photoluminescence (PL) spectroscopy. Our results revealed that both the activation energy of the PL emission intensity and the PL decay lifetime exhibit sharp increases at x of around 0.4. The results can be understood in terms of the sharp increase of the impurity binding energy or the carrier/exciton localization energy around x=0.4. A three orders of magnitude increase in resistivity of undoped AlGaN alloys at x of around 0.4 was also observed, which further corroborated the optical results.
|Number of pages||3|
|Journal||Applied Physics Letters|
|State||Published - Nov 12 2001|