Optical and Electrical Characterization of Bulk-Grown Ternary In$_{x}$Ga$_{1-x}$As*

Crystal growth technology breakthroughs have led to the growth of good quality melt-grown bulk In$_{x}$Ga$_{1-x}$As crystals. These crystals are promising candidates for electro-optical applications in the infra red. The optical and electrical properties of bulk In$_{x}$Ga$_{1-x}$As have been investigated as a function of temperature and indium mole fraction. Photoluminescence (PL) measurements show several band edge luminescence peaks including band-to-band, free-to-bound, and donor-acceptor pair peaks. Temperature dependent bandgaps were estimated from the PL results. The carrier concentrations and mobilities were determined by the Hall-effect measurements. The bandgaps estimated from the Hall-effect and optical transmission measurements were compared with those obtained from the PL results.