Laplace-DLTS of Cu(In,Ga)Se2-based devices

Laplace transform DLTS as an alternative to standard DLTS technique is presented and employed for investigation of trap spectra in photovoltaic devices based on Cu(In,Ga)Se-2. The examples showing very good spectral resolution and accuracy of Laplace-DLTS analysis of emission spectra due to majority carrier traps in the absorber and to interface states are presented. Owing to that, light-induced metastabilities of emission related to interface states can be investigated in much more detail, than by other junction techniques. The method also helps to distinguish between thermally activated processes and other non-thermal sources of capacitance decay.