Energy band bowing parameter in MgZnO alloys

Abstract

We report on bandgap bowing parameters for wurtzite and cubic MgZnO alloys from a study of high quality and single phase films in all Mg content range. The Mg contents in the MgZnO films were accurately determined using the energy dispersive spectrometer and X-ray photoelectron spectroscopy (XPS). The measurement of bandgap energies by examining the onset of inelastic energy loss in core-level atomic spectra from XPS is proved to be valid for determining the bandgap of MgZnO films. The dependence of the energy bandgap on Mg content is found to deviate downwards from linearity. Fitting of the bandgap data resulted in two bowing parameters of 2.01 ± 0.04 eV and 1.48 ± 0.11 eV corresponding to wurtzite and cubic MgZnO films, respectively.

Structural and Optical Properties of Zn1‐xMgxO Prepared by Calcination of ZnO + Mg(OH)2 after Hydro Micro Mechanical Activation

“…The linear slope we obtained is not in contradiction with the theoretical calculation of ref. [] where the bandgap of w‐ZnO, was taken at 7.5 eV. In fact, the linear extrapolation of our data targets the experimental value of 6.4 eV, a value also significantly smaller than the proposed “ad‐hoc” theoretical value of 7 eV …”

Experimental Evidence of Large Bandgap Energy in Atomically Thin AlN

“…As is well known, XPS can be used to analyze the inelastic collisions in photoexcitation and photoemission of electrons from the material . For insulators or wide bandgap semiconductors, the onset of the inelastic energy loss spectra corresponds directly to the bandgap energy .…”

“…High‐resolution scan of the N 1s core‐level photoelectric peak (located at binding energy of E N1s = 396.5 eV) is shown in Figure a. A linear fit (the inclined red line) is made to the measured loss spectra near the approximate location of the onset of the inelastic losses . Then, the background “zero” level (the horizontal red line) is determined parallel to the horizontal axis by subtracting the Shirley background fitting.…”

Accessing Metastability in Heterostructural Semiconductor Alloys

“…Figure A shows this qualitatively different behavior using heterostructural Mg x Zn 1‐ x O alloys as an example. In this material system a transition from the hexagonal wurtzite to the cubic NaCl structure is observed leading to a discontinuous change in the optical bandgap at the structural transition point . The dashed lines represent the hypothetical evolution of the band gap in an isostructural case fitting a combination of experimental and theoretical data points.…”