On relation between detection parameters of SI GaAs particle detectors and physical properties of starting materials

Investigation of defect levels in semi-insulating materials by modulated and transient photocurrent: comparison of methods

“…The activation energy for the T1 trap is in very good agreement with the energy of 0.42-0.45 eV corresponding to the hole emission from the positively ionized chromium centre: Cr 4+ (3d 2 ) → Cr 3+ (3d 3 ) + h + (VB). The activation energy for trap T3 is consistent with the energy of 0.67-0.70 eV corresponding to the electron emission from the negatively ionized chromium centre: Cr 2+ (3d 4 ) → (Cr 3+ (3d 3 ) + e − (CB). Hence, the trap T3 can be identified with the chromium acceptor level Cr 3+ /Cr 2+ i.e.…”

“…Semi-insulating (SI) materials have received more and more attention as their potential applications were growing. These materials enter into different fields of applications such as substrates for high speed electronic and optoelectronic integrated circuits [1,2], radiation and particle detectors [3][4][5] or photorefractive sensor devices [6,7]. The quality of SI materials used in one domain or the other is strongly affected by deep levels related to impurities and native defects.…”