Time-resolved photoluminescence of GaN/Al[sub 0.5]Ga[sub 0.5]N quantum wells.

We report photoluminescence (PL) and time-resolved PL measurements of GaN/Al[sub x]Ga[sub 1-x]N 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 ∼0.5 ns. Dependence of lifetime on emission energy is very small compared to InGaN quantum wells, indicating that carrier localization is very slight and interface quality is high. In 4 nm wells, PL emission at an energy below the bulk GaN band gap and long recombination lifetimes result from the polarization field across the wells. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]