Effect of Al Doping on the Structural, Electrical, Gas Sensing Properties of ZnO Nanorods Synthesized by Hydrothermal Growth

摘要

The effect of Al doping on the morphology and sensing properties of ZnO nanorods have been shown. Undoped and Al-doped well-aligned ZnO nanorods have been grown on sputtered ZnO/SiO2/Si (100) pre-grown seed layer substrate by the hydrothermal method. The molar ratio of dopant (aluminum nitrate) in the solution, [Al/Zn], was varied from 0.1% to 3%. The prepared ZnO nanorods showed preferred orientation <0001> and were well aligned vertically. We observed that for 0.5% Al doping the diameter and resistivity of the nanorods became the least, carrier concentration became large. Sensing behavior of the doped samples tested for H2 gas shows the sensitivity of ～60% at 250°C and ～50% at 220°C, respectively.