Investigation of Electric Field Effect on Defects in GaAsN by Admittance Spectroscopy

We use the Arrhenius transformation and matching (ATM) method to extract activation energy and attempt-to-escape frequency of the nitrogen-related defect (E1) in GaAsN from admittance spectroscopy measurements taken at various temperature and electric field. The ATM method is equivalent to the conventional Arrhenius plot and line-fitting (APL) method for Arrhenius processes with temperature-independent Ea and ν0 (e.g., E1 in a low electric field and at high temperatures) and advantageous for non–Arrhenius processes with temperature-dependent Ea and ν0, (e.g., E1 in a high electric field and at low temperatures), where the APL method is not reliable. The ATM method enables a detailed account on how Ea evolves with the temperature and the electric field in a continuously varying experimental space, which is not possible with the APL method. The evolution of carrier emission behaviors from the E1 defect and a neighboring E2 defect provides experimental evidence of field-induced metastability possibly due to the interaction of two defects with close atomic origins or spatial locations.