ELECTRIC-FIELD EFFECT ON THE EMISSION OF ELECTRON-IRRADIATION-INDUCEDDEFECTS IN N-GAAS

The enhancement of the emission rate of electron-irradiation-induced d efects in the presence of an electric field in n-type GaAs with carrie r concentrations ranging from 1 X 10(14) to 1 X 10(16) cm-3 has been i nvestigated using deep level transient spectroscopy (DLTS). The relati onship between the electric field strength and the emission rate of th e three major electron traps (E1, E2 and E3) in electron-irradiated n- type GaAs material is presented. Using the models for phonon-assisted tunnel emission of electrons from deep levels developed by Pons et al. and the enhancement due to Poole-Frenkel potential barrier lowering a correlation was attempted between the experimental results and those predicted by the above-mentioned two models. From these results an est imate of the Franck-Condon shift for the three defects is presented.