Improvement of CZTSSe thin film solar cell by introducing a three-layer structure precursor

• Cu and Zn vertical distribution is controlled by a three-layer CZTS precursor.
• Controlled distribution of element can promote the grain growth during annealing.
• Efficiency of CZTSSe solar cell gets an increase of 3.54%.

CZTSSe thin films based on three-layer precursors with Cu-poor and Zn-rich in top and bottom layer while stoichiometric in middle layer were prepared. Compared with CZTSSe thin film obtained from a stoichiometric single layer precursor, the crystallization of thin film from a three-layer precursor got enhanced. Element distribution and growth nuclei position in precursor played an important role on CZTSSe thin film formation and solar cell performance. The conversion efficiency of CZTSSe solar cell from a three-layer precursor attained an increase of 3.54% over that from a single layer precursor.

Excess Zn in the bottom layer helps balance the composition there. Excess Zn in the upper layer promotes the growth of CZTSSe grains. Crystallization of CZTSSe film from a three-layer precursor got enhanced. An increase of 3.54% in conversion efficiency was obtained using a three-layer precursor.Figure optionsDownload as PowerPoint slide