Nondestructive atomic compositional analysis of BeMgZnO quaternary alloys using ion beam analytical techniques

Abstract

HighlightsBeMgZnO thin layers were grown with plasma assisted molecular beam epitaxy (MBE)The Be contents were accurately measured with RBS and proton elastic backscattering The Tauc bandgap was measured from optical transmittance experiments The bandgap has been varied between 3.26 eV and 4.62 eV via the Be and Mg content Experimental and density functional theory calculated bandgaps were in good agreement AbstractThe atomic composition with less than 1-2 atom % uncertainty was measured in ternary BeZnO and quaternary BeMgZnO alloys using a combination of nondestructive Rutherford backscattering spectrometry with 1 MeV He + analyzing ion beam and nonRutherford elastic backscattering experiments with 2.53 MeV energy protons. An enhancement factor of 60 in the cross-section of Be for protons has been achieved to monitor Be atomic concentrations. Usually the quantitative analysis of BeZnO and BeMgZnO systems is challenging due to difficulties with appropriate experimental tools for the detection of the light Be element with satisfactory accuracy. As it is shown, our applied ion beam technique, Page 2 of 22A c c e p t e d M a n u s c r i p t supported with the detailed simulation of ion stopping, backscattering, and detection processes allows of quantitative depth profiling and compositional analysis of wurtzite BeZnO/ZnO/sapphire and BeMgZnO/ZnO/sapphire layer structures with low uncertainty for both Be and Mg. In addition, the excitonic bandgaps of the layers were deduced from optical transmittance measurements. To augment the measured compositions and bandgaps of BeO and MgO co-alloyed ZnO layers, hybrid density functional bandgap calculations were performed with varying the Be and Mg contents. The theoretical vs. experimental bandgaps show linear correlation in the entire bandgap range studied from 3.26 eV to 4.62 eV. The analytical method employed should help facilitate bandgap engineering for potential applications, such as solar blind UV photodetectors and heterostructures for UV emitters and intersubband devices.

Lattice parameters and electronic structure of BeMgZnO quaternary solid solutions: Experiment and theory

“…This discrepancy also partially originates from slight variations in the actual Be and Mg atomic contents (see Table I) from the plotted 9% and 39%, respectively, as well as the error in measurement of the lattice parameters (see Table I) and the compositions. 14 The error bars shown in Figure 4 represent the corresponding overall confidence limits. The measurement error results partially from alloy XRD peak broadening and use of the relatively weak and broad low-temperature ZnO XRD peak as the reference position for asymmetric XRD scans.…”

“…More detailed discussion of the sample preparation can be found in the previous reports. 7,14 We used first principles calculations to analyze structure and electronic properties of quaternary BeMgZnO alloys. The structural properties were calculated using PerdewBurke-Ernzerhof (PBE) 15 parameterization of the GGA 16 to the DFT.…”

On the mechanisms of hydrogen-induced blistering in RF-sputtered amorphous Ge

“…Good agreement was found between ERDA and RBS by simulating their spectra with the RBX code [23]. As it was shown, combined ion beam analytical techniques are powerful in the quantitative characterization of multi-component thin layer structures [24].…”

Doping silica beyond limits with laser plasma for active photonic materials

“…Rutherford Backscattering Spectrometry (RBS) is a powerful technique for non-destructive compositional analysis of thin layers and nanostructured materials [16,17]. In this work, RBS analysis was performed in a scattering chamber with a two-axis goniometer connected to the 5 MV EG-2R Van de Graaff accelerator of the Institute for Particle and Nuclear Physics at the Wigner Research Centre for Physics (Wigner FK RMI) in Budapest, Hungary.…”