2017 年 54 巻 1 号 p. 27-31
Aluminum doped zinc oxide (AZO) was synthesized with various pH adjustments reagent (ammonia, TMAH, TEAH and TPAH) by hydrothermal reaction. Regardless of the pH adjustment, the main product of the synthesized powders with 5 mol% Al was zinc oxide. However, the diffraction peaks of gahnite (ZnAl2O4) were detected in the sample prepared from the precursor solutions with TMAH, TEAH and TPAH as pH adjustment. The excellent absorption property in near-infrared (NIR) region was obtained in the synthesized powder with about 2 mol% Al using ammonia. Based on these results, the initial state of Zn and Al ion in precursor solution is thought to affect the crystal phase of the product in hydrothermal synthesis. The NIR absorption property was highly enhanced by using urea as the pH-shift reagent during hydrothermal reaction process.