Formation of buried 2D Aluminium Gallium Nitride structures with enhanced piezoelectric modulus by xenon ion implantation. (February 2023) - Fiedler, Holger
Highlights: Formation of 2-dimensional wurtzite AlGaN. Strained metastable AlGaN phase with Xe noble gas interstitial. Energetic ion beams provide formation energy for strained Xe:AlGaN. Alternating planar and buckled 2D monolayers with changing polarization. Abstract: Two-Dimensional (2D) III-V nitrides are anticipated to exhibit exceptional material properties with wide-ranging technological significance. We report, ion beam synthesis of buried 2D Aluminium Gallium Nitride structures with enhanced piezoelectric modulus. We propose three criteria for the formation of 2D AlGaN layers by ion implantation. The 2D layers were synthesized by Xe implantation into epitaxially grown, strain-free Al0.5 Ga0.5 N thin films and their presence was confirmed by scanning transmission electron microscopy. Alternating planar and buckled 2D III-Nitride layers in conjunction with a rapid change of polarity of the buckled layer confirms the weak interaction between the individual layers. Rutherford backscattering, in conjunction with piezoelectric force microscopy was used to identify the optimum Xe dose to induce maximum enhancement of piezoelectric modulus. Our results are supported by X-ray diffraction to quantify the macroscopic strain of the implanted film and Monte-Carlo simulations of ion-solid interactions. Fabrication of this material on a large scale may lead to highly efficient energy harvesters, communication devices, power devices and photocatalytic water splitting technologies. Graphical abstract: Image, graphical abstract