All-Vacuum-Deposited Bifacial Cu₂ZnSnSe₄ Photovoltaic Cells with Sputtered Cd-Free Buffer Layer

Figure 7

(a) XRD and Raman measurements of the 1-cycle-P specimen and 4-cycle-P specimen at different stages of selenisation; (b) schematic diagram of CZTSe thin-film growth mechanism.

(a)

(b)