The Study of Optical and Electrical Characteristics of Transparent Conducting Oxide Multilayer Films

• Main Authors: Shang-Hao Chang, 張尚豪
• Other Authors: Kuo-Sheng Kao
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/37750584642541604420

碩士 === 樹德科技大學 === 電腦與通訊研究所 === 97 === Transparent conducting oxide (TCO) is an essential material for optoelectronic devices. The TCO film is also used as electrode. The common materials for TCO are In2O3, SnO2 and ZnO. The indium tin oxide (ITO) is adopted widely for its excellent properties. Because the ITO is also used in liquid crystal display (LCD), the price of indium is advanced more then decuple. The great importance has been attached to the low price zinc oxide (ZnO). Therefore, the zinc oxide (ZnO) with impurity doped and metal-based ZnO multilayer structures are reported as good transparent conducting electrodes in the replacement of ITO. In this study, the structure by optimizing the thickness of metal alloy and ZnO individual layers is emphasized. The metal thin film will be deposited by DC magnetron sputtering with well thicknesses control. The ZnO film deposition is performed by spin-coating technique and dried at suitable temperature on glass and flexible substrate. Due to the conductivity of ZnO/metal/ZnO is dominated by metal layer, the sheet resistance of ZnO/metal/ZnO decrease dramatically as the thickness of metal layer increases. However, the transmittances of ZnO/metal/substrate become unacceptable for TCO application after the thickness of metal layer beyond 10 nm. We will use the Four-Point probe method to measure the electrical property, use the UV/VIS spectrophotometer to evaluate the transmission, employ an atomic force microscopy (AFM) to measure roughness of the thin films, use the X-ray diffraction to identify the crystalline structure of thin films, and utilize a Hall measuremnet system to observe the basic semiconductor parameters. In order to meet TCO criteria, we adjust thin film fabricating parameters in accordance with the measurement result and basic physic characteristic.