High‐throughput method to deposit continuous composition spread Sb2(SexS1 − x)3thin film for photovoltaic application

Abstract

AbstractSb2(SexS1 − 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(SexS1 − 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 Vocand Jscdemonstrated an opposite evolution trend. The champion device with the composition of Sb2(Se0.68S0.32)3achieved the Vocand Jsctrade‐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(SexS1 − x)3film and their CDE fabrication technique were expected to efficiently screen materials and promote the development of antimony chalcogenide solar cells.