Characteristic investigation and photodetection analysis on Zn1−xHgxO nanoflakes for near ultraviolet-visible photodetectors

Abstract

The optical band gap of ZnO was modified with the incorporation of Hg ions by co-precipitation method and is taken up for the fabrication of near ultraviolet-visible (NUV-Vis) photodetectors (PDs). Detailed characteristic investigations were carried out using X-ray diffractometer (XRD), transmission electron microscope (TEM), UV-Vis spectrometer and X-ray photoelectron spectrometer (XPS) preceding the fabrication of NUV-Vis photodetectors. The anticipated incorporation of Hg ions into the hexagonal wurtzite structure of ZnO was confirmed by XRD and XPS analysis. A red shift in the ZnO band gap of about ∼0.8 eV was observed from optical analysis. Well-appreciated detection of NUV-Vis wavelength was achieved with PDs fabricated using different concentrations of Hg doped ZnO, particularly 15% Hg doping, which showed a maximum responsivity of 64 mA/W and quantum efficiency of 19.86%.