Radiative and nonradiative recombination process in InN films grown by metal organic chemical vapor deposition

摘要

In a recent letter, Intartaglia et al. reported the radiative and nonradiative recombination process in InN films grown by metal organic chemical vapor deposition. The authors studied the photoluminescence (PL) spectra as a function of temperature and time. In their experiments, the luminescence signal of InN was detected by cooled InGaAs photomulti-plier (80 K). It is worthwhile to point out that the typical response cutoff on the long-wavelength side of the InGaAs photomultiplier is around 1700 nm. It is not safe to use an InGaAs photomultiplier to conduct InN PL analysis for the reason that the band-gap energy of InN (～0.7 eV) is just too close to its cutoff edge. By carefully checking the series of PL spectra reported by Intartaglia et al, we found that the PL intensity sharply decreases when the energy approaches 0.76 eV from the peak around 0.77 eV. It is likely that the cutting off of the response of the InGaAs detector in this range contributes to this result.