LAUSR

Three different elements, silicon, selenium, and tellurium, are ion-implanted in gallium arsenide to form a conducting layer that serves as a back-gate to a molecular beam epitaxy overgrown two-dimensional electron gas. While the heavy ion tellurium creates too many defects in the gallium arsenide to form a conducting layer, both silicon and selenium show promising results combined with MBE-grown high-quality 2DEGs. Similar 2DEG mobilities compared to non-implanted reference samples are achieved for both silicon and selenium implanted structures. Individual contacts to the back-gate are challenging. However, silicon implanted structures, annealed before the MBE growth, result in a functional back-gate, and the electron density of the 2DEG can be tuned via the structured back-gate.