Sodium Assisted Sintering of Chalcogenides and Its Application to Solution Processed Cu2ZnSn(S,Se)4 Thin Film Solar Cells

详细信息    查看全文

• 作者：Carolin M. Sutter-Fella ; Josua A. Stückelberger ; Harald Hagendorfer ; Fabio La Mattina ; Lukas Kranz ; Shiro Nishiwaki ; Alexander R. Uhl ; Yaroslav E. Romanyuk ; Ayodhya N. Tiwari
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：February 11, 2014
• 年：2014
• 卷：26
• 期：3
• 页码：1420-1425
• 全文大小：367K
• ISSN：1520-5002

文摘

Cu₂ZnSn(S,Se)₄ thin layers processed from solution-deposited earth-abundant precursors emerge as absorber materials for low-cost thin film solar cells. A frequently observed drawback of the chemical solution processing鈥攑oor crystallinity of the chalcogenide absorber鈥攃an be overcome by employing a sodium-containing reactive agent. We demonstrate a massive improvement in grain growth in the presence of sodium. It enhances the surface chemisorption of selenium molecules and can promote the formation of liquid Na₂Se_x phases during reactive annealing of the precursor. The sodium is also incorporated into the semiconductor absorber and significantly modifies its electronic properties. By adjusting the sodium precursor quantity, it is possible to tune doping levels and gradients to maximize the collection of photogenerated carriers in thin film Cu₂ZnSn(S,Se)₄ solar cells. The presented approach can be extended to other solution-processed metal chalcogenides to enhance their structural and electronic properties, which are critical for applications such as thin film solar cells and transistors.