Below bandgap emission with intensity higher than band‐to‐band transition in GaAsN

Abstract

The existence of energy level inside the band gap energy of GaAsN was discussed in this paper. The photoluminescence (PL) spectrum of the GaAsN epilayers grown by metal‐organic chemical vapor deposition (MOCVD) consists of two distinguished peaks separated by 0.2 eV energy difference. First peak belongs to the energy band gap transition emission, while the second peak resides at longer wavelength with intensity more than ten times stronger than that of the band‐to‐band emission. The activation energy of this second emission peak is found to be 113 meV. The peak shows a characterization of a defect in the epilayer where its PL intensity decreases when the GaAsN epilayer was exposed to rapid thermal annealing (RTA). This type of defect related emission is the first reported in as‐grown GaAsN epilayer. This defect emission peak can be overcome with optimization of V/III ratio during the MOCVD growth combined with post‐growth RTA annealing. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Properties of GaAsN layers grown from melt containing Li3N as flux for enhancing nitrogen dissolution

“…The full-width at half-maximum (FWHM) of the layer peak is 59 arcsec which is close to that for the substrate peak of 53 arcsec, indicating good crystallinity of the grown GaAsN material. GaAsN layers grown by MOVPE or MBE with similar nitrogen contents usually show much broader x-ray diffraction (XRD) peaks with the FWHM lying in the range 90-120 arcsec [23][24][25]. 10 K PL spectrum for the GaAsN layer is shown in figure 3 along with that for an undoped LPE GaAs layer from the first batch.…”

Study of nitrogen incorporation into (In, Ga) as grown by metal organic chemical vapor deposition

“…This is because additional nitrogen introduces higher lattice mismatch between GaAsN and GaAs. Each percent of nitrogen incorporated into GaAsN causes 0.2% lattice strain [74]. This amount is large enough to hinder incorporation of nitrogen.…”