Structural and optical properties of (In,Ga)2O3 thin films and characteristics of Schottky contacts thereon

We report on structural and optical properties of a (InxGa1-x)(2)O-3 thin film having a monotonic lateral variation of the indium content x (0 <= x <= 0.9). The growth condition for each In content is similar allowing precise determination of the dependence of material properties on x. For low In content (x < 0.15) the thin film has monoclinic crystal structure; for highest In contents (x > 0.8) the cubic bixbyite phase is predominant. For intermediate alloying we observe additionally the rhombohedral InGaO3(II) crystallographic phase. The optical band-gap decreases systematically with increasing indium content and has a linear dependency on x for parts of the sample having the monoclinic phase, only. Further, properties of Pt Schottky diodes are reported for monoclinic (InxGa1-x)(2)O-3 and photo response measurements for x < 0.1