High‐throughput method to deposit continuous composition spread Sb₂(Se_xS_{1 − x})₃thin film for photovoltaic application

Sb₂(Se_xS_1 − x)₃alloy materials with tunable bandgaps combining the advantages of Sb₂S₃and Sb₂Se₃showed high potential in low cost, non‐toxicity, and high stability solar cells. The composition dependence of device performance becomes indispensable to study. However, traditional approaches often implement 1 composition at a time, which easily lead to long period and systematic errors. The present work developed a high‐throughput experimental method, close‐space dual‐plane‐source evaporation (CDE) method, to successfully deposit continuous composition spread Sb₂(Se_xS_1 − x)₃library at 1 time. On the surface of the obtained film, thexvalue of Se content evolved from 0.09 to 0.84 by a series of complementary characterizations. At depth direction, the alloy film kept high crystallinity and composition consistency. Solar cell arrays (19 × 6) were fabricated to investigate the relationship between compositions and performances. As the increase of Se content, the conversion efficiency first increased from 1.8% to 5.6% and then decreased to 5%. The V_ocand J_scdemonstrated an opposite evolution trend. The champion device with the composition of Sb₂(Se_0.68S_0.32)₃achieved the V_ocand J_sctrade‐off exceeding the performances of Sb₂S₃(2.43%) and Sb₂Se₃(4.97%) devices. Cryogenic and transient characterizations were utilized to investigate the distinct performance evolution mechanism. There existed shallow defect levels in Se‐rich alloys and deep defects in sulfur‐rich ones. The widely tuned absorber compositions combined with distinct defect characters induced to the large variation of device performance. The present continuous composition spread Sb₂(Se_xS_1 − x)₃film and their CDE fabrication technique were expected to efficiently screen materials and promote the development of antimony chalcogenide solar cells.