Ag-doped ZnO hydrogen sensor grown by the USP method

Abstract

Undoped and Ag doped ZnO thin films were grown on glass substrate at 500 °C by ultrasonic spray method (USP). In order to observe the effect of Ag doping on ZnO thin films, doping rates of 0.5%, 1%, 2%, 3% and 4% were carried out. Some measurements were taken to investigate the effects of Ag dopant for example Uv–Vis spectroscopy and photoluminescence (PL) measurements for optical, scanning electron microscope (SEM) measurements for morphological, X-ray Diffraction (XRD) and Energy Dispersive X-ray spectroscopy (EDAX) measurements for structural, sensor measurements for H2 sensor properties. Uv–Vis spectroscopy and photoluminescence (PL) measurements show that the band gap of ZnO decreased from 3.21 eV to 2.79 eV and PL intensity of ZnO from 3.21 eV to 2.79 eV with increasing amount of Ag dopant. SEM measurements show that surface morphology changed and shrinkage was observed on the surface with Ag dopant. XRD results show that the presence of Ag peaks was found in the crystal structure of Ag doped ZnO thin films and EDAX measurements have supported this AG presence in the ZnO structure. Hydrogen sensor measurements show that the sensor response decreased from 92.7% to 45.6% with the increase of Ag dopant.