Carrier recombination properties in low-temperature-grown and ion-implanted GaAs

Abstract

Electron and hole trapping times, electron mobilities were investigated in low-temperature-grown GaAs (LTG GaAs) and GaAs crystals implanted by four different ion species. Optical pump – THz probe and recently developed optical pump – mid-IR probe techniques have been used in these experiments. Recombination parameters of the investigated materials were estimated in point of view of possible applications of these materials in THz radiation devices. It has been concluded that LTG GaAs is preferable material for pulse THz applications because of its shorter electron trapping times and higher electron mobility. However, the hole trapping time in ion-implanted material is shorter than in LTG GaAs, making it a suitable for devices working in cw-mode, e. g. THz photomixers. The shortest carrier trapping times and the largest electron mobility were found for O-implanted GaAs.