New technique for identification of deep-level trap emission to indirect conduction minima in GaAs

Abstract
A new analysis of the CV characteristics of the depletion region of a Schottky barrier in the presence of deep‐level traps is presented which yields the absolute position of the energy level in the energy band diagram. It is found that for the commonly observed 0.830±0.005 eV electron trap in VPE GaAs, the level is located at 0.543 eV (240 K) and 0.537 eV (120 K) below the Γ conduction minimum. It is shown that this level emits electrons to the L minima and, that relative to these minima, exhibits a zero temperature coefficient. The capture cross section for this center is σ= (1.8±0.4) ×10−14 cm2 and has a zero activation energy over the temperature interval 120–240 K.