The excitation photocapacitance method is applied under a constant capacitance condition to study Te-doped GaAs bulk crystals, prepared by annealing at 900°C for 67 h under extremely high arsenic vapor pressure (4817 Torr). Photocapacitance measurements after monochromatic light irradiation reveal two deep levels at 0.50 and 0.68 eV above the valence band only during photoquenching. By varying the primary excitation photon energy, the emission and the capture photon energies are strictly determined depending on the change of the charge states of the excess arsenic atom-related levels.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry