Characteristics of Al-doped ZnO nanorods synthesized by the hydrothermal process at Low temperature

Abstract

In this study, the Al-doped ZnO (AZO) nanorods were synthesized on silicon substrate by the hydrothermal process. The SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /silicon substrate was submerged horizontally in 0.06M mixture solution of zinc nitrate hexahydrate (Zn(NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ·6H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O), diethylenetriamine (DETA), and doped the solution of aluminium nitrate, nonahydrate (Al(NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ·9H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O) at about 90°C for 4h. It has been shown that the ZnO nanorods are of single hexagonal phase of wurtzite structure. SEM image revealed that the range of diameter of ZnO nanorods about 83 ~ 425 nm. In addition, the ZnO nanorods/Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O/Si structure was utilized as a pH sensor head to immerse into various pH buffer solutions. Experimental results were found that the Al-doped ZnO nanorods have a pH response. Afterwards, the sensor head will be designed the extended-gate field-effect transistor (EGFET) to study the pH-sensing characteristics in the different pH buffer solutions.