Influence of N interstitials on the electronic properties of GaAsN alloys

We have used rapid thermal annealing to investigate the influence of N interstitials on the electronic properties of GaAsN alloys. Nuclear reaction analysis reveals an annealing-induced decrease in the interstitial N concentration, while the total N composition remains constant. Corresponding signatures for the reduced interstitial N concentration are apparent in Raman spectra. Following annealing, both the room-T carrier concentration, n, and the mobility increase. At higher measurement-Ts, a thermally activated increase in n suggests the presence of a trap near GaAsN conduction band edge with activation energy 85±15 meV. The annealing-induced increase in n suggests the association of the trap with interstitial N.