Fig xA PL emissions of CIS thin film
Furthermore, the full-width-at-half-maximum (FWHM) of the PL spectra of SQW (~140 meV) is much broader than that of the excitonic emission of CGS (~10 meV). In addition, the FWHM is almost independent on the temperature. Therefore, this broadness of SQW emission is probably caused by the Ga and In interdiffusion at the interface of CGS and CIS. On the other hand, there is no obvious temperature variation in the PL emission energies in CIS SQW.