Effects of CdS Buffer Layers on Photoluminescence Properties of Cu₂ZnSnS₄ Solar Cells

Figure 4

PL spectra at 20 K obtained for different excitation powers ( nm) on the as-grown CZTS samples after the etching procedure in aqueous HCl. The band energy shift per decade of laser power of the emission at 1.21 eV is reported in the inset.