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

Figure 1

Schematic diagram of experiment. In this experiment, the most basic 1-cycle-P precursor was gradually modified into a 4-cycle-P precursor. Subsequently, after completing the selenisation reaction (using three-stage heating), the film of the CZTSe absorption layer was produced. Subsequently, the buffer layer, window layer, and upper electrode were deposited by sputtering. In the inset, (a), (b), and (c) labelled on the heating curve are the measurements obtained after staged heating and taking the test piece out in order to further understand the difference between the reaction mechanism of 1-cycle-P and that of 4-cycle-P.