Bias-dependent photo-detection of dual-ion beam sputtered MgZnO thin films

Abstract

The structural, morphological, elemental and electrical properties of MgZnO thin films, grown on p-Si (001) substrates by dual-ion beam sputtering deposition (DIBSD) system at different substrate temperatures were thoroughly investigated. X-ray diffraction (XRD) pattern of MgZnO film exhibited crystalline hexagonal wurtzite structure with the preferred (002) crystal orientation. The full-width at half-maximum of the (002) plane was the narrowest with a value of 0.226 • from MgZnO film grown at 400 • C. X-ray photoelectron spectroscopy analysis confirmed the substitution of Zn 2+ by Mg 2+ in MgZnO thin films and the absence of MgO phase. Correlation between calculated crystallite size, as evaluated from XRD measurements, and room-temperature carrier mobility, as obtained from Hall measurements, was established. Current-voltage characteristics of MgZnO thin films were carried out under the influence of dark and light illumination conditions and corresponding values of photosensitivity were calculated. MgZnO film grown at 100 • C exhibited the highest photosensitivity of 1.62. Compared with one of the best-reported values of photosensitivity factor from ZnO-material-based films available in the literature, briefly, ∼3.085-fold improved photosensitivity factor at the same bias voltage (2 V) was obtained.

Effect of Gamma Radiation on Structural and Optical Properties of ZnO and Mg-Doped ZnO Films Paired with Monte Carlo Simulation

“…The selection of Mg (Group II element) as a dopant has considerable benefits as Mg ion has a similar radius to Zn ion, which in turn allows facilitation of a wider optical bandgap shifting Fermi level through the creation of impurity states that varies with doping concentration [10] where such addition is beneficial in order to improve or modify the electrical and optical properties [11]. Furthermore, the replacement of Zn by Mg should not cause a significant change in the lattice constant and thus preventing a lattice mismatch, making it a suitable pairing for a heterojunction combination as large crystal structure difference between wurzite hexagonal ZnO can cause unstable phase mixing [12].…”

Structural and Optical Properties of ZnO and MgZnO Semiconductor Materials at Different Annealing Temperature

“…However, a large crystal structure difference between the wurtzite-hexagonal ZnO (a = 3.25 Å and c = 5.21 Å) and the rocksalt-cubic MgO (a = 4.21 Å) can cause unstable phase mixing (Pandey & Mukherjee, 2016;Chen & Kang, 2008). Depending on growth ASM Science Journal, Volume 13, 2020 2 conditions, MgZnO may have a cubic or a hexagonal lattice.…”