Effect of processing conditions of co-precipitation on the characteristics of transparent conductive aluminum-doped zinc oxide materials

• Main Authors: Chen Sung Chang, 張振崧
• Other Authors: H. C. Lu
• Format: Others
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/26724311490678302935

碩士 === 長庚大學 === 化工與材料工程研究所 === 97 === The objectives of this research were to synthesize nano-sized powders of transparent conductive aluminum-doped zinc oxide (AZO) with controlled composition (2 wt% Al2O3) by co-precipitation method and to prepare AZO ceramics through ceramic processing using these co-precitated AZO nano-powders. In addition, the effects of processing conditions during co-precitation on the characteristics of these AZO materials were also investigated. From the experimental results, it was shown that crystalline AZO nano-powders with particle size around 30 nm can be synthesized by cacining at 600 oC for 2 hours the precursors that were co-precipitated at pH=8 and ice-bathed conditionusing KOH as precipitant and then dried at 80 oC. AZO green bodies were made from these AZO nano-powders through the processes of ball milling, granulation, dry pressing, iso-static pressing, and dewaxing. By sintering the dewaxed AZO green bodies under Ar atmosphere with positive pressure, the decomposition of AZO could be suppressed and the resistivity of the sintered AZO ceramics was found to decrease when the Ar pressure increased. When sintered at 1400oC for 3 hours under Ar pressure of 50kPa, AZO ceramics with composition of ZnO:Al2O3=98.1 wt% : 1.9 wt%, relative density of 99.55%, and lowest resistivity of 5.4*10-4 Ωcm could be obtained.