Wet Coating of Transparent Conductive Oxide (AZO) Film

• Main Authors: Huang-pin Chien, 錢皇賓
• Other Authors: Anthony S.T. Chiang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/41304913102342763093

碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 96 === Significant progress has been made in transparent conductive oxide (TCO) films, largely motivated by the emergence of LCD and solar cell industries. In the search for a cheaper and indium-free materials to replace the traditional ITO, aluminum-doped zinc oxide (AZO) has been the leading candidate. Therefore, the objective of this research is to identify experimentally the controlling factors that ultimately govern the transparency and electrical conductivity of AZO film. ZnO nanoparticles of size 5~6 nm have been successfully synthesized previously in our Lab by titrating zinc chloride with sodium hydroxide in ethylene glycol solution, followed by low temperature aging. However, such method has two serious drawbacks – the production of unwanted sodium chloride byproduct, and a low concentration (4 wt%). This would require multiple coatings and sintering needed to achieve the desired thickness. To achieve the desired AZO film thickness with a single coating, the concentration of ZnO solution must be about 50 wt%. At the same time the NaCl byproduct must be remove. Using PGME as a co-solvent to dissolve hexane in EG, ZnO nanoparticles were precipitaled while redisperse after evaporation of hexane. TGA analysis showed an increased in weight percent (64 wt%). After dilution with methanol to 30 wt%, the as-prepared film with one dip-coating cycle was sintered in air at 400oC. The resulting film showed a transparency of higher than 90% and a thickness of 300 nm as measured by SEM. Subsequent study involved the dopping of aluminum and sintering conditions on the electrical conductivity and transparency of AZO films. Variables sadas sintering atomsphere and temperature were also tested to study their respective impacts.