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

Abstract

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.

Role of Cu/S ratio and Mg doping on modification of structural and optical characteristics of nano CuS

“…9 The mono dispersed CuS nanocrystals exhibited energy gap ~1.5 eV. 15 Also, the same trend was observed in Mg-doped nano TiO 2 due to diminishing of the crystallite size upon doping. The optical energy gap for Mg-doped CuS increased from 1.27 to 1.79 eV as CuS doped up to 40%Mg, Figure 1C.…”

“…2 The results indicated that the energy gap of CuS matrix changed irregularly with increased Mn-doped amount, whereas it exhibited a regular decreasing as the amount of Fe increased in CuS. 15 In this study, the tailoring of the band gap of nano CuS can be achieved by either changing the ratio of Cu and S in CuS or doping CuS with Mg. 2 Magnesium ion is considered the most acceptable p-type dopant for III-V compound semiconductor materials due to its nontoxicity and noncarcinogenic.…”

“…13 In our previous study, we examined the effect of Mn and Fe on optical properties of CuS prepared by thermolysis procedure in air. [15][16][17][18][19][20] Furthermore, Mg-doped systems can be used in several fields such as ultraviolet optoelectronic devices, ultraviolet photo-detectors and short wavelength light emitting machines. Also, the photoluminescence intensity is enhanced as CuS doped with 10% Mn or Fe then it quenched by further doping.…”

“…14 Moreover, as Mg-doped semiconductor materials, their energy gaps can be altered due to the influence of crystallite size and/or the presence of Moss-Burstein effect. [15][16][17][18][19][20] Furthermore, Mg-doped systems can be used in several fields such as ultraviolet optoelectronic devices, ultraviolet photo-detectors and short wavelength light emitting machines. 15 In this study, the tailoring of the band gap of nano CuS can be achieved by either changing the ratio of Cu and S in CuS or doping CuS with Mg.…”

“…[15][16][17][18][19][20] Furthermore, Mg-doped systems can be used in several fields such as ultraviolet optoelectronic devices, ultraviolet photo-detectors and short wavelength light emitting machines. 15 In this study, the tailoring of the band gap of nano CuS can be achieved by either changing the ratio of Cu and S in CuS or doping CuS with Mg. The effect of Cu to S ratio changing and Mg-doped CuS on the structural, optical, and emission behavior were investigated in details using X-ray diffraction, scanning electron microscope, Fourier transforms infrared, ultraviolet spectroscopy, and photoluminescence techniques.…”