Fig. 2. Raman spectra of a reference CZTSe (black) and sulfurized CZTSe absorbers with various heater powers (40% (red), 45% (green), and 50% (blue), one 30 second spike). The Raman excitation wavelength was 532 nm and the spectra were normalized with respect to their background around 150 cm−1. The inlet graph shows magnified spectra for the sulfur-related “CZTS-like peak” region.
