Optical and Electrical Properties of Bulk-grown Ternary In_xGa_(1−x)As

Bulk ternary In_xGa_(1−x)As polycrystals were grown using the vertical Bridgman technique. The optical and electrical properties of these bulk In_xGa_(1−x)As were investigated as a function of indium mole fraction from 0.75 to 0.99 by using photoluminescence (PL) and Hall-effect measurements. All samples showed good infrared transmission. A free exciton (FX) transition peak was observed from all bulk In_xGa_(1−x)As samples, and it redshifted from 0.568 to 0.412 eV as the indium mole fraction increased from 0.75 to 0.99. Bandgaps estimated from the indium compositionand temperature-dependent FX peaks generally followed the theoretically calculated bandgaps. All as-grown In_xGa_(1−x)As samples showed n-type conductivity. Although all bulk In_xGa_(1−x)As samples showed good optical transmissions and PL transitions, as well as high carrier mobilitites, they exhibited some random compositional fluctuations across the sample area. KCI Citation Count: 1