Dependence of the Electrical and Optical Properties of Molecular Beam EpitaxialIn(0.52)Al(0.48)As on Growth Parameters: Interplay of Surface Kinetics and Thermodynamics

摘要

The optical and transport properties of In0.52Al0.48As grown by molecular beamepitaxy have been studied as a function of growth temperature in the range of 300-520 C. It is evident that under our growth conditions, thermodynamic considerations become important, and combined with surface kinetics, clustering effects become most severe for important, and combined with surface kinetics, clustering effects become most severe for growth temperatures around 400 C. The clustering effects are manifested by changes in low-temperature photoluminescence, Hall transport and in the properties of Schottky diodes made on the films and the relevant parameters show a peaking for growth at 400 C. In particular, the Hall mobility exhibits a turning point for T > 300 K, beyond which the mobility increases with increasing temperature. In addition, the Hall electron concentration exhibits an anomalous reduction in value in the same high-temperature range. Measurements were also made on In0.52Al0.48As grown at 620-650 C by metal-organic chemical vapor deposition. While these films exhibit the same turning point in Hall mobility, the reduction in carrier concentration is significantly absent. Keywords: Molecular beam epitaxy, Ternary compounds, Clustering, Reprints. (js)