Quenching phenomenon of hopping conduction in neutron-transmutation-doped semi-insulating GaAs

Abstract

The quenching phenomenon in tunneling-assisted hopping conduction below 125 K has been observed in neutron-transmutation-doped semi-insulating GaAs irradiated with a fast-neutron fluence of 3.7\ifmmode\times\else\texttimes\fi{}${10}^{18}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$. No quenchable component is observed in as-irradiated GaAs, while the EL2 or EL2-like defects are generated by annealing above 250 \ifmmode^\circ\else\textdegree\fi{}C and activated as the quenchable component in the hopping conduction. The EL2 (or EL2-like) defects are likely to be formed by the interaction of the As antisite and a mobile defect such as the As interstitial and divacancy (As vacancy + Ga vacancy). According to the tunneling-assisted hopping model, the concentration of the quanchable component generated is larger than that of the native EL2 defect decomposed in irradiated GaAs.