Study the best ratio of S and Se in CZTSSe solar cells with nontoxic buffer layer

Cu2ZnSn(S-x, Se1-x)(4) (CZTSSe) material has attracted more and more researchers' attention due to its low cost, environmental protection, high absorption coefficient, and adjustable bandgap. The classic structure of CZTSSe solar cell is Al: ZnO (AZO)/i-ZnO/CdS/CZTSSe, so it is very important to find a suitable buffer layer material to replace the toxic cadmium (Cd). Therefore, the performance of solar cells with different buffer layers is compared. The buffer layer is replaced by the indirect bandgap n-In2S3, which has high stability and light transmittance. And in this work, spectroscopic ellipsometry is used to measure the absorption coefficient spectrum of the absorber layer CZTSSe with different sulfur-to-selenium ratio, and wxAMPS numerical simulation software is used to simulate various material properties and draw conclusions. When X = 0.4, the performance of the CZTSSe TFSC reaches the optimal value.

Automated summary

The CZTSSe material is attracting attention for its low cost, environmental friendliness, high absorption coefficient, and adjustable bandgap. Researchers are focusing on finding suitable buffer layer materials to replace toxic cadmium in CZTSSe solar cells. This study utilized spectroscopic ellipsometry and numerical simulation software to analyze the impact of different buffer layers on solar cell performance, finding that the CZTSSe thin film solar cell performance is optimal when the sulfur-to-selenium ratio is X=0.4.