Figure 2

Time-integrations of time-resolved PL spectra collected at low temperature from the two porous GaN samples (a) p-GaN/(111)Si and (b) p-GaN/MOCVD-GaN measured using 300 grooves/mm grating. Restricting the integration to long delays after the laser excitation pulse permits is to clearly reveal the existence of stacking faults leading to I₁ (3.42 eV) and I₂ (3.35 eV) related recombinations. In the high energy range the PL is due to confined free (FE) and donor-bound (D₀X) excitons recombination.