Fabrication and Characterization of Zinc Oxide Window Layers by Low-Temperature Wet Chemical Synthesis for CIGS Thin Film Solar Cells

• Main Authors: Chung-Wei Wu, 吳忠衛
• Other Authors: Rong-Fuh Louh, Chien-Yie Tsay, Pei-Ling Sun
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/18754112424249405367

碩士 === 逢甲大學 === 材料科學所 === 97 === We used two wet chemical synthesis methods, namely, to fabricate the zinc oxide (ZnO) thin film on the polyethylene terephthalate (PET) film as flexible polymer substrate. The relationship between microstructure and optical properties of ZnO films and process conditions of both CBD and SILAR were thoroughly explored. In CBD process, the type of precursors as zinc ion source, concentration of chemical bath, and the deposition temperature and time were investigated along with the use of different complexing agents such as ammonium nitrate and sodium citrate to effectively control growth mechanism of ZnO film. In SILAR process, the number of deposition cycles is a strong connection to the final thickness and microstructure pf ZnO films. The adhesion strength and film failure modes of deposited ZnO films were examined under a substrate bending tester with various bending angle and folding length. The optimized process parameters derived from CBD and SILAR techniques for PET substrates were also employed to other available substrates including stainless steel foil, glass, and silicon wafer to compare resultant performances of film deposition. Moreover, the post-deposition heat treatment was used to promote the densification of ZnO films and to enhance its optical and crystallnity for the applications as window layers of Cu(In,Ga)Se2 or CIGS thin film solar cells. The ZnO film through rapid microwave annealing had satisfactory optical property and crystallnity. The ZnO films on flexible PET substrates with thickness of 30~130 nm and transmittance over 90% can be achieved by CBD and SILAR.