Electrical and Structural Characterizations of Cu(InGa)Se2 Thin Films Using Electrochemical Capacitance–Voltage Method and Focused-Ion Beam Process

Abstract
The electrochemical capacitance–voltage (ECV) method and the focused-ion beam (FIB) process were adopted for the evaluation of device-quality Cu(InGa)Se2 (CIGS) films. The profiling of the carrier concentrations and the structural properties were successfully carried out by the ECV and FIB methods, respectively. It was found from the ECV measurements that the hole concentration of CIGS film grown by the selenization method was in the order of 1017 cm-3. Furthermore, the FIB process showed that the CIGS films grown by the selenization method had voids in the film. These results indicate that both methods are practical and effective tools for characterizing the CIGS thin films.