Enhanced Photocurrents with ZnS Passivated Cu(In,Ga)(Se,S)2 Photocathodes Synthesized Using a Nonvacuum Process for Solar Water Splitting

详细信息    查看全文

• 作者：Sang Youn Chae ; Se Jin Park ; Sung Gyu Han ; Hyejin Jung ; Chae-Woong Kim ; Chaehwan Jeong ; Oh-Shim Joo ; Byoung Koun Min ; Yun Jeong Hwang
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：December 7, 2016
• 年：2016
• 卷：138
• 期：48
• 页码：15673-15681
• 全文大小：569K
• ISSN：1520-5126

文摘

Chalcopyrite Cu(In,Ga)(Se,S)₂ (CIGS) semiconductors are potential candidates for use in photoelectrochemical (PEC) hydrogen generation due to their excellent optical absorption properties and high conduction band edge position. In the present research, CIGS thin film was successfully prepared on a transparent substrate (F:SnO₂ glass) using a solution-based process and applied for a photocathode in solar water splitting, which shows control of the surface state associated with sulfurization/selenization process significantly influences on the PEC activity. A ZnS passivation surface layer was introduced, which effectively suppresses charge recombination by surface states of CIGS. The CIGS/ZnS/Pt photocathode exhibited highly enhanced PEC activity (∼24 mA·cm^–2 at −0.3 V vs RHE). The performances of our CIGS photocathode on the transparent substrate were also characterized under front/back light illumination, and the incident photon to current conversion efficiency (IPCE) drastically changed depending on the illumination directions showing decreased IPCE especially under UV region with back illumination. The slow minority carrier (electron) transportation is suggested as a limiting factor for the PEC activity of the CIGS photocathode.