Photoluminescence study of InGaN/GaN double quantum wells with varying barrier widths

We report the results of photoluminescence (PL) and time-resolved PL studie s on InGaN/GaN double quantum well (DQW) samples with different barrier wid ths. The barrier-width dependence of the PL emission energy and intensity a re discussed. The PL as a function of excitation density can be well explai ned in terms of the quantum-confined Stark effect (QCSE). The temporal beha vior of the PL was also studied. As the barrier width increases, the decay times tau(1) and tau(2), decrease from 1.02 ns and 6.99 ns to 0.32 ns and 1 .09 ns, respectively. The PL efficiency and the decay lifetime depend on th e barrier width.