Mg-doped Thin Films Research Articles

Stabilization and enhanced energy gap by Mg doping in ε-phase Ga2O3 thin films

Mg-doped Ga2O3 thin films with different doping concentrations were deposited on sapphire substrates using laser molecular beam epitaxy (L-MBE) technique. X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and ultraviolet-visible (UV-vis) absorption spectrum were used to characterize the crystal structure and optical properties of the as-grown films. Compared to pure Ga2O3 thin film, the Mg-doped thin films have transformed from the most stable β-phase into ε-phase. The absorption edge shifted to about 205 nm and the optical bandgap increased to ∼ 6 eV. These properties reveal that Mg-doped Ga2O3 films may have potential applications in the field of deep ultraviolet optoelectronic devices, such as deep ultraviolet photodetectors, short wavelength light emitting devices and so on.

Electronic defects in In2 O3 and In2 O3 :Mg thin films on r -plane sapphire

The electrical and structural properties of undoped and Mg-doped pulsed-laser-deposited In2O3 thin films grown on r-plane sapphire were investigated by means of Hall-effect, X-ray diffraction, and space-charge spectroscopic methods, such as thermal admittance spectroscopy and deep-level transient spectroscopy. Undoped thin films are preferentially -oriented but X-ray diffraction also revealed -orientation. The incorporation of Mg promotes growth along the direction. Further, the free electron concentration is reduced from to values below due to incorporation of MgO. We found that a deep-level defect with a thermal activation energy of and an apparent capture cross-section of is exclusively incorporated in Mg-doped thin films.