The van der Waals epitaxial growth of GaSe on Si(111)

Abstract

GaSe, a layered semiconductor, may be grown on the Si͑111͒ surface by molecular beam epitaxy. The crystalline quality is relatively good, in the sense that the MeV 4 He ion minimum channeling yield (ϳ30%) is as low as that of state-of-the-art bulk material, and the interface is atomically abrupt. The initial film deposits are epitaxial islands, and subsequent growth is in the Frank-van der Merwe mode. With the islands already relaxed at the nucleation stage and coalescing to essentially uniform coverage with the first monolayer of deposition, GaSe on Si͑111͒ provides an example of van der Waals epitaxy. However, it is difficult to understand how epitaxy ͑crystallographic alignment with the substrate͒ can occur in such a case, where the film is incommensurate starting from the initial nuclei. A mechanism for alignment of the islands is proposed: they are aligned with the silicon substrate through the influence of dangling bonds at their perimeter, being ''quasicommensurate '' by virtue of their small lateral size. Although discommensurate regions are created as the islands grow laterally, there is simply no change in their orientation. © 1997 American Institute of Physics. ͓S0021-8979͑97͒05011-1͔

Tunable quasiparticle band gap in few-layer GaSe/graphene van der Waals heterostructures

“…Among the all possible substrate for large and controllable GaSe growth, epitaxial graphene provides several potential advantages for the creation of vdW heterostructure such as: high quality on a wafer scale, high electron mobility, and crystalline ordering that can template commensurate substrate 24,25 . Single and few TL of GaSe were directly grown on bilayer graphene/SiC(0001) substrate with MBE to avoid contamination introduced by chemical transfer 26 . The GaSe films were grown in a MBE equipped with standard effusion cells.…”

Epitaxial orientations ofpara-sexiphenyl platelets grown on alkali halide (001) surfaces

“…Hence this system constitutes an ideal case of van der Waals epitaxy. 40,41 The problem of analyzing preferential epitaxial orientations has its origins in the classic works of Frank and van der Merwe. 35 We note that the one-dimensional lattice match found for the H0 and H45 arrangements closely resembles the Nishiyama-Wasserman arrangement of an fcc ͑111͒ adlayer on a bcc ͑110͒ substrate 33,34 along high-symmetry azimuths.…”

A Very Stable Cyclic DNA Miniduplex with Just Two Base Pairs

“…A layer of hydrogen (H) atom becomes absorbed on the surface, causing Si(111) to be (1 × 1) structured 52. This surface has been previously adopted for the Van der Waals growth of layered GaSe on Si 53. A study comparing the growth of Bi 2 Se 3 on Si(111) with/without hydrogen termination has been carried out, resulting in a “significant improvement” in the surface terrace size 47.…”