Detector structure on defect-rich silicon and fast-response wide-gap semiconductor materials

The monopolar and bipolar drift regimes have been analyzed by using dynamic models based on the Shockley-Ramo theorem. Profiling of the injected charge drift current transients in Si particle detectors has been implemented by varying charge injection position within a cross-sectional boundary of the particle detector. It has been shown that the mixed regime of the competing processes of drift, recombination, and diffusion appears in the measured current profiles on the irradiated samples. The carrier multiplication processes determined by impact ionization have been considered in order to compensate carrier lifetime reduction due to introduction of radiation defects into GaN detector material. Capacitor and Schottky diode sensors were fabricated on GaN material. The operational characteristics of these devices have been investigated by profiling current transients and by comparing the experimental regimes of the perpendicular and parallel injection of excess carrier domains. Current transients under injection of the localized and bulk packets of excess carriers have been examined in order to determine the surface charge formation and polarization effects. The absolute values of carrier recombination lifetime in different type Si materials and irradiated with various type penetrative hadrons (neutrons, protons, pions) fit the same calibration curve