Time-resolved PL spectra at T = 100 K for sample 201.
(a) PL excited from the front side. (b) PL excited from the backside (through the sapphire substrate). The points are the PL intensity at indicated time delays (in μs) after the laser pulse. The solid line is the steady-state PL spectrum at Pexc = 1 mW/cm2 (arbitrarily shifted along the vertical axis for comparison with the time-resolved PL spectrum at 100 μs). The dashed and dotted lines are calculated using Eq. (3) with the following parameters: Se = 8.5, E0* = 2.93 eV, ħωmax = 2.40 eV (for the GL1 band) and Se = 7.4, E0* = 2.66 eV, ħωmax = 2.20 eV (for the YL1 band).