Time-resolved photoluminescence of GaN/Al0.5Ga0.5N quantum wells

We report photoluminescence (PL) and time-resolved PL measurements of GaN/A lxGa1-xN multiple quantum wells with barriers of high aluminum content, x = 0.5. In wells of width 1-2 nm, low temperature recombination appears to be dominated by radiative processes with lifetimes similar to 0.5 ns. Depende nce of lifetime on emission energy is very small compared to InGaN quantum wells, indicating that carrier localization is very slight and interface qu ality is high. In 4 nm wells, PL emission at an energy below the bulk GaN b and gap and long recombination lifetimes result from the polarization field across the wells. (C) 2000 American Institute of Physics. [S0003-6951(00)0 3433-1].