Spontaneous formation of monocrystalline nanostripes in the molecular beam epitaxy of antimony triselenide.

Self-assembled, highly anisotropic nanostructures are spontaneously formed in the molecular beam epitaxy of antimony triselenide on GaAs substrates. These one-dimensional (1D) nanostripes have all the orientations parallel to the substrate surface and preserve the epitaxial relationship with the substrate. The shape of the nanostripes is directly related to the highly anisotropic stibnite structure of antimony triselenide which consists of 1D ribbons held together by weak van der Waals forces.

Formation of GeO under Graphene on Ge(001)/Si(001) Substrates Using Water Vapor.

The problem of graphene protection of Ge surfaces against oxidation is investigated. Raman, X-Ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurements of graphene epitaxially grown on Ge(001)/Si(001) substrates are presented. It is shown that the penetration of water vapor through graphene defects on Gr/Ge(001)/Si(001) samples leads to the oxidation of germanium, forming GeO.

Growth of highly oriented MoSvia an intercalation process in the graphene/SiC(0001) system.

A method of growing highly oriented MoS is presented. First, a Mo film is deposited on a graphene/SiC(0001) substrate and the subsequent annealing of it at 750 °C leads to intercalation of Mo underneath the graphene layer, which is confirmed by secondary ion mass spectrometry (SIMS) measurements. Formation of highly oriented MoS layers is then achieved by sulfurization of the graphene/Mo/SiC system using HS gas.

Destructive role of oxygen in growth of molybdenum disulfide determined by secondary ion mass spectrometry.

The application of secondary ion mass spectrometry (SIMS) in investigation and comparison of molybdenum disulfide (MoS2) films grown on SiO2, Al2O3 and BN substrates is presented. SIMS measurements of the MoS2/substrate interface reveals oxygen out-diffusion from the substrates containing oxygen and the formation of an amorphous MoOS layer in addition to MoS2. The total area of MoS2 domains covering the substrate is directly related to the type of substrate.

Formation of a highly doped ultra-thin amorphous carbon layer by ion bombardment of graphene.

Ion bombardment of graphene leads to the formation of defects which may be used to tune properties of the graphene based devices. In this work, however, we present that the presence of the graphene layer on a surface of a sample has a significant impact on the ion bombardment process: broken sp bonds react with the incoming ions and trap them close to the surface of the sample, preventing a standard ion implantation. For an ion bombardment with a low impact energy and significant dose (in the range of 10 atoms cm) an amorphization of the graphene layer is observed but at the same time, most of the incoming ions do not penetrate the sample but stop at the surface, thus forming a highly doped ultra-thin amorphous carbon layer.