Charge Carrier Recombination in AlGaAs Studied by Time-Resolved Microwave Conductivity Experiments

Abstract

AbstractAlxGa1-xAs films, doped with silicon in the 1 x 1018 cm-3 range, have been prepared in the composition range x = 0.20 - 0.46 by molecular beam epitaxy. The influence of defect states on excess carrier trapping and recombination processes is studied by a contactless transient photoconductivity technique in the microwave region. Effective electron life- times in the 1 x 10-5s range for the 20% Al film down to the 1 x 10-7s range for the 46% Al film were found, indicating a larger density of electron traps in more Al rich films. The decay kinetics in AlGaAs is compared with the decay kinetics in GaAs.