Deep-level characterization studies for optically controlled semiconductor switch materials using a novel technique

Deep level characterization studies have been made for different semiconductor materials (such as chromium doped GaAs, GaAs:Si:Cu, semi-insulating GaAs, polycrystalline ZnSe) of interest for photoconductive pulse power switches. Photo Induced Current Transient Spectroscopy technique using a digital approach for data acquisition has been used for measuring deep level parameters, such as activation energy, trap concentration and capture cross-section for electron and hole capture. Of particular interest to us is information n copper levels and EL2 levels in silicon doped copper compensated GaAs, which has been shown to perform as optically controlled closing and opening switch. The analysis of the current transient is performed by using two different methods a standard rate window method and a curve fitting method. The results obtained by both the methods are compared.