Sputter deposition of sulfide solar-cell absorber thin films by using a hot-wall reflector toward low-temperature low-cost fabrication process

2014 Fiscal Year Final Research Report

• Project/Area Number: 24656450
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Material processing/treatments
• Research Institution: Kanazawa Institute of Technology
• Principal Investigator: KUSANO Eiji 金沢工業大学, バイオ・化学部, 教授 (00278095)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: スパッタリング / CZTS / 熱反射壁

Outline of Final Research Achievements

The feasibility of composition and property controls by the use of the hot reflector wall, which is intended to enhance the probability that Zn and S atoms re-evaporated from the growing thin film surface re-impinge on the film surface, has been investigated in one-step rf-sputter deposition of Cu2ZnSnS4. It is shown that the use of the reflector wall suppresses the composition deviation of Zn and S from the stoichiometry and improves the crystallinity evaluated by X-ray diffraction, showing a larger crystalline diameter of 16-26 nm, especially in thin films deposited at a high substrate temperature of 400 °C and by using the reflector wall with a temperature of 400 °C. In addition, optical band gap decreases to 1.6 -1.7 eV for all substrate temperatures. It is concluded that the use of the reflector wall suppresses the composition deviation from the stoichiometry in the quaternary compound thin films, resulting in the improvement of optical and electrical properties.

Free Research Field

薄膜堆積プロセス