Intraband relaxation time in wurtzite InGaN quantum-well lasers and comparison with experiment

The intraband relaxation time for wurtzite (WZ) 3.5-nm In0.15Ga0.85N/In0.02Ga0.98 N quantum well (QW) lasers is investigated theoretically. The results are also compared with those obtained from fitting the experimental data with a non-Markovian gain model with many-body effects. An intraband relaxation time of 25 fs is obtained from the comparison with experiment, which is in reasonably good agreement with the calculated value of 20 fs at the subband edge. These values are significantly shorter than those (40 - 100 fs) reported for zinc-blende crystals, such as InP and GaAs. This is because the hole effective masses of GaN are larger than those of GaAs and InP.