Photoluminescence Studies and Solar-Cell Application of CuInSe2 Thin Films Prepared using Selenization Techniques

Abstract
Photoluminescence measurements were carried out on CuInSe2 thin films prepared using the selenization technique with solid- or vapor-phase selenium, and the correlation between photoluminescence spectra and cell performance was studied. In our previous studies, several peaks were observed in the wavelength region below 1400 nm in the photoluminescence spectra of low-photovoltaic CuInSe2 thin films. In contrast, in the spectra of high-photovoltaic films, a strong peak was observed at 1420 nm, and there were no additional peaks below 1400 nm. From the results, it was found that there was a strong correlation between the photovoltaic effect of CuInSe2 thin films and the existence of the photoluminescence peak at 1420 nm. The origin of this peak and its behavior were investigated through the dependence of the photoluminescence spectra on the temperature and excitation intensity and the effect of air annealing.