Characterization of H2 Plasma Pretreatment of Seed Layer on Synthesis ZnO Nanorods

• Main Authors: Yao-Ju Chen, 陳耀儒
• Other Authors: Mi Chen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/45021913789895870130

碩士 === 明新科技大學 === 化學工程與材料科技研究所 === 100 === ZnO (Zinc Oxide) is a wide band gap (3.37eV) semiconductor with a large exciton binding energy (60meV). 1-D ZnO nano-materials with excellent optical and electrical properties can be used in nanoelectronics and optoelectronic devices. In this thesis, Well-aligned ZnO nanorods were rapidly grown on ITO glass substrate using AZO thin film as seed layer by microwave hydrothermal method. The optimal ZnO growth conditions were obtained by adjusting the seed layer H2 plasma pretreatment time and synthesis time. H2 plasma effect of the seed layer on the alignment, growth rate and crystallinity of ZnO nanorods has been studied. The prepared ZnO nanorods were annealed in various gases to enhance the optical properties. X-ray photoelectron spectroscopy (XPS) analysis was used to determine the composition and chemical bounding state. Characteristic and optical properties of ZnO nanorods synthesized on graphene/ ITO substrate were investigated. The results show that the alignment and growth rate of ZnO nanorods depends on the characteristic and roughness of the seed layer, which can be improved by H2 plasma pretreatment. The average growth rate of ZnO nanorods synthesized by microwave hydrothermal method is about 2.2 μm/hr which significantly superior to other techniques. Zn/O atomic ratios are 1.09, 0.98, and 0.96 with 20, 40, 60 min ZnO nanorods synthesis time. The oxygen contents decrease with increasing reaction time. Due to the number of oxygen vacancies increase. After N2 annealing treatment good quality ZnO nanorods were obtained. ZnO nanorods are single crystal with stacking defects and pyramid or candle shape. ZnO nanorods synthesis on graphene/ITO substrate has high electronic mobility and specific surface area while fabricated as working electrode of dye-sensitized solar cells (DDSCs). The conversion efficiency is 2 times than ZnO nanorods synthesis on ITO substrate. ZnO soaked in dye would decrease light absorbance that decrease the conversion efficiency of ZnO as an electrode of DSSCs.