Tight-binding analysis of the electronic states in AlAs with N isoelectronic impurities

摘要

Incorporation of nitrogen (N) atoms into III–V semiconductors significantly changes their electronic structures. The aim of this study was to assess the electronic states in AlAs that contained N impurities. An sp3s* tight-binding model along with valence-force-field strain calculations were used to obtain the energy levels in N-doped AlAs. The calculations showed that an isolated N atom formed a resonant state above the conduction band edge in AlAs. In contrast, NN1[110] and NN4[220] pairs formed bound states inside the band gap. The formation of two bound states was consistent with the photoluminescence spectrum of N δ-doped AlAs.