Spectroscopic Studies of Heavily Carbon-Doped GaAs Grown by Metal Organic Chemical Vapor Epitaxy

Abstract

Spectroscopic studies of the minority electron lifetimes and photo-luminescence efficiencies of heavily carbon-doped GaAs are reported. The GaAs layers were grown by metal organic chemical vapor epitaxy (MOVPE) at 650 °C with carbon tetrabromide used as a dopant source. Combined minority electron lifetime and internal quantum efficiency measurements allowed us to determine the radiative decay times in heavily carbon-doped GaAs to be longer than that we would expect if a value for the radiative recombination constant of B = 2.0 × 10−10 cm3 s−1 were used. Taking into account the effects of hole–hole and hole–ionized impurity scattering, we show that B decreases as hole density increases in heavily carbon-doped GaAs. With the use of the revised values for B, the calculated radiative decay times were compatible with our measurements. Index Headings: Radiative decay times; Luminescence efficiency; Radiative recombination constant; Carrier–carrier interaction; Band structure changes.