Dlts Analysis of Radiation-Induced Defects in InGaAsN Solar Cell Structures

摘要

We present the direct observation of majority and minority carrier defects in InGaAsN diodes and solar cells before and after 1-MeV electron irradiation by deep level transient spectroscopy (DLTS). A hitherto existing nitrogen-related electron trap, E1, (0.20 eV) shows a significant increase in concentration after 1-MeV electron irradiation. In addition, 1-MeV electron irradiation induced a hole trap, H1, at energy of about 0.75 eV above the valence band. Isothermal annealing analysis indicates that E1 is a complex defect involving an interstitial or a substitutional atom in combination with some other defect, whose concentration is enhanced by irradiation. The recovery of the free carrier concentration following the recovery of the E1 level upon annealing indicates that the E1 center is an acceptor-like center