Structural and electronic properties of zincblende phase of TlxGa1−xAsyP1−y quaternary alloys: First-principles study

Using the first-principles band-structure method, we have calculated the structural and electronic properties of zincblende TlAs, TlP, GaAs and GaP compounds and their new semiconductor TlxGa1−xAsyP1−y quaternary alloys. Structural properties of these semiconductors are obtained with the Perdew and Wang local-density approximation. The lattice constants of TlxGa1−xAs, TlxGa1−xP ternary and TlxGa1−xAsyP1−y quaternary alloys were composed by Vegard’s law. Our investigation on the effect of the doping (Thallium and Arsenic) on lattice constants and band gap shows a non-linear dependence for TlxGa1−xAsyP1−y quaternary alloys. The band gap of TlxGa1−xAsyP1−y, Eg(x, y) concerned by the compositions x and y. To our awareness, there is no theoretical survey on TlxGa1−xAsyP1−y quaternary alloys and needs experimental verification.