Conduction Band Edge Discontinuity of In0.52Ga0.48As/In0.52(Ga1-xAlx)0.48As(0≦x≦1) Heterostructures

Abstract
In0.52Ga0.48As/In0.52(Ga1-x Al x )0.48As/In0.52Ga0.48As potential barrier structures (x=0.25, 0.5, 0.75, 1), lattice-matched to InP, were grown by MBE using a pulsed molecular beam method. The conduction band edge discontinuity, ΔE c(x) between In0.52Ga0.48As and In0.52(Ga1-x Al x )0.48As, was obtained for the first time by measuring the current-voltage characteristics through the barrier structure as a function of temperature in the range of 77–300 K. It was confirmed that the conduction band edge discontinuity varies linearly with Al composition, x, (ΔE c(x)=0.53x(eV) for 0≦x≦1) and is proportional to the band gap difference, ΔE g(x), (ΔE c(x)=0.72ΔE g(x)(eV) for 0≦x≦1).