Affiliation:
1. Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, School of Chemistry and Materials Science University of Science and Technology of China Hefei 230026 China
2. Institute of Photoelectronic Thin Film Devices and Technology of Nankai University Tianjin 300350 China
3. Department of Environmental Science and Engineering University of Science and Technology of China Hefei 230026 P. R. China
Abstract
AbstractBand structure of a semiconducting film critically determines the charge separation and transport efficiency. In antimony selenosulfide (Sb2(S,Se)3) solar cells, the hydrothermal method has achieved control of band gap width of Sb2(S,Se)3 thin film through tuning the atomic ratio of S/Se, resulting in an efficiency breakthrough towards 10 %. However, the obtained band structure exhibits an unfavorable gradient distribution in terms of carrier transport, which seriously impedes the device efficiency improvement. To solve this problem, here we develop a strategy by intentionally regulating hydrothermal temperature to control the chemical reaction kinetics between S and Se sources with Sb source. This approach enables the control over vertical distribution of S/Se atomic ratio in Sb2(S,Se)3 films, forming a favorable band structure which is conducive to carrier transport. Meanwhile, the adjusted element distribution not only ensures the uniformity of grain structure, but also increases the Se content of the films and suppress sulfur vacancy defects. Ultimately, the device delivers a high efficiency of 10.55 %, which is among the highest reported efficiency of Sb2(S,Se)3 solar cells. This study provides an effective strategy towards manipulating the element distribution in mixed‐anion compound films prepared by solution‐based method to optimize their optical and electrical properties.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Anhui Provincial Development and Reform Commission