Electron radiation damage in Cu(In,Ga)Se2 analysed in‐situ by cathodoluminescence in a transmission electron microscope

Abstract

AbstractThis contribution describes the first results of a completely new approach to study in‐situ the radiation damage properties of semiconductors, particularly of Cu(In,Ga)Se2 thin solar films by cathodoluminescence in TEM. This method proved to be sensitive to the initial damage processes that occur on an atomic level and are thus inaccessible otherwise in the microscope. The in‐situ character of the investigation permits to analyze also the defect formation kinetics directly. We discuss the development of the cathodoluminescence spectra in dependence of electron dose and accelerating voltage for Cu(In1–xGax)Se2 with [Ga]/([Ga] + [In]) ratio x ranging from x = 0 to x = 1. The obtained results indicate that the films with equal Ga and In concentration are the least radiation sensitive ones. The voltage dependence of the damage rate indicates that the damage arises essentially due to displacement by electron knock‐on (in the voltage range 150–300 kV). The defect formation kinetics can be interpreted with a first model which is supported by annealing experiments. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)