The band offset at CdS/Cu2ZnSnS4 heterojunction interface

• Published in: Electronic materials letters Vol. 8; no. 4; pp. 365 - 367
• Main Authors: Li, Ji, Du, Qingyang, Liu, Weifeng, Jiang, Guoshun, Feng, Xuefei, Zhang, Wenhua, Zhu, Junfa, Zhu, Changfei
• Format: Journal Article
• Language: English
• Published: Springer The Korean Institute of Metals and Materials 01.08.2012; 대한금속·재료학회
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed Matter Physics; Materials Science; Nanotechnology; Nanotechnology and Microengineering; Optical and Electronic Materials; 전자/정보통신공학; Cu; band offset; ZnSnS; solar cells; heterojunction
• ISSN: 1738-8090; 2093-6788
• DOI: 10.1007/s13391-012-2023-0

The band offset at the CdS/Cu 2 ZnSnS 4 heterojunction interface is studied by measuring the valence band spectra using synchrotron radiation photoemission spectroscopy. The Cu 2 ZnSnS 4 thin films are prepared by the sulfurization of electrodeposited Cu-Zn-Sn precursors. A CdS overlayer is sequentially grown on the Cu 2 ZnSnS 4 thin films from a chemical bath deposition process. Valence band spectra were obtained before and after each period of growth to study the electronic structure at the heterojunction interface. The valence band offset was determined to be 0.96 eV, and the conduction band offset was determined to be −0.06 eV. This means that the CdS/Cu 2 ZnSnS 4 hetrojunction has a ‘type II’ band alignment which will cause large-scale recombination at the interfaces and will not be suitable for solar cells fabrication.