Fengjuan Liu

Solar-Blind Photoresistors Based on

Solar-blind photoresistors based on Mg_0.48Zn_0.52O thin films were fabricated on r-plane sapphire substrates by radio-frequency plasma-assisted molecular beam epitaxy. High-quality a-plane-orientation single-phase wurtzite Mg_0.48Zn_0.52O thin films are demonstrated by X-ray diffraction and absorption spectra. The MgZnO photoresistors exhibit a large dark/photoresistance ratio up to 1.7 × 10⁴ with the light intensity of 0.61 mW/cm² at 260 nm. The spectral response shows a sharp response peak only in the solar-blind region with maximum responsivity of 1.5 × 10^-3 Ω^-1· W^-1.

\hbox{Mg}_{0.48} \hbox{Zn}_{0.52}\hbox{O}

Structural and optical properties of ZnO epilayers grown on r -plane sapphire substrates by plasma-assisted molecular-beam epitaxy have been investigated using various techniques. A high-purity wurtzite structure and a smooth surface with an a-plane orientation were obtained. The resonant Raman scattering spectra show a typical multiphonon vibration characteristic from wurtzite ZnO. A good near band gap luminescence property is revealed in photoluminescence spectra.