A5033537321- Graphene research and applications
- Nanowire Synthesis and Applications
- 2D Materials and Applications
- Heusler alloys: electronic and magnetic properties
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and interfaces
- Surface and Thin Film Phenomena
- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Ferroelectric and Piezoelectric Materials
- Advanced Memory and Neural Computing
- Magnetic Field Sensors Techniques
- Terahertz technology and applications
- Magnetic properties of thin films
- Advancements in Battery Materials
- MXene and MAX Phase Materials
- Ion-surface interactions and analysis
- Advancements in Semiconductor Devices and Circuit Design
- Intermetallics and Advanced Alloy Properties
- Topological Materials and Phenomena
- Diamond and Carbon-based Materials Research
- Photonic and Optical Devices
University of Wisconsin–Madison
2021-2024
Remote epitaxy is a promising approach for synthesizing exfoliatable crystalline membranes and enabling of materials with large lattice mismatch. However, the atomic scale mechanisms remote remain unclear. Here we experimentally demonstrate that GaSb films grow on graphene-terminated (001) via seeded lateral mechanism, in which pinhole defects graphene serve as selective nucleation sites, followed by coalescence into continuous film. interactions are not necessary order to explain growth....
The epitaxial growth of functional oxides using a substrate with graphene layer is highly desirable method for improving structural quality and obtaining freestanding nanomembranes scientific study, applications, economical reuse substrates. However, the aggressive oxidizing conditions typically used in growing can damage graphene. Here, we demonstrate successful use hybrid molecular beam epitaxy SrTiO 3 that does not require an independent oxygen source, thus avoiding damage. This approach...
Remote epitaxy is promising for the synthesis of lattice-mismatched materials, exfoliation membranes, and reuse expensive substrates. However, clear experimental evidence a remote mechanism remains elusive. Alternative mechanisms such as pinhole-seeded or van der Waals can often explain resulting films. Here, we show that growth Heusler compound GdPtSb on clean graphene/sapphire produces 30° rotated (R30) superstructure cannot be explained by pinhole epitaxy. With decreasing temperature,...
We demonstrate selective area epitaxy of GaAs films using patterned graphene masks on a Ge (001) substrate. selectively grows exposed regions the substrate for stripe widths 10 μm. The selectivity is highly dependent growth temperature and annealing time, which we explain in terms sticking coefficients surface diffusion. high nucleation over several micrometers sets constraints experimental realizations remote epitaxy.
Understanding the sticking coefficient $\ensuremath{\sigma}$, i.e., probability of an adatom to a surface, is essential for controlling stoichiometry during epitaxial film growth. However, $\ensuremath{\sigma}$ on monolayer graphene-covered surfaces and its impact remote epitaxy are not understood. Here, using molecular-beam growth magnetic shape memory alloy ${\mathrm{Ni}}_{2}\mathrm{MnGa}$, we show that coefficients metals MgO (001) less than one temperature element dependent, as revealed...
The synthesis of functional graphene nanostructures on Ge(001) provides an attractive route toward integrating graphene-based electronic devices onto complementary metal oxide semiconductor-compatible platforms. In this study, we leverage the phenomenon anisotropic growth nanoribbons from rationally placed nanoseeds and their rotational self-alignment during chemical vapor deposition to synthesize mesoscale nanomeshes over areas spanning several hundred square micrometers. Lithographically...
We use epitaxial lateral overgrowth (ELO) to produce semimetallic graphene nanostructures embedded in a semiconducting GaAs matrix for potential applications plasmonics, THz generation and detection, tunnel junctions multijunction solar cells. show that (1) the combination of low sticking coefficient fast surface diffusion on enhances nucleation selectivity at exposed regions substrate (2) high growth temperatures favor efficient overgrowth, coalescence, planarization films over...
Abstract Single-crystalline membranes of functional materials enable the tuning properties via extreme strain states; however, conventional routes for producing require use sacrificial layers and chemical etchants, which can both damage membrane limit ability to make them ultrathin. Here we demonstrate epitaxial growth cubic Heusler compound GdPtSb on graphene-terminated Al 2 O 3 substrates. Despite presence graphene interlayer, films have registry underlying sapphire, as revealed by x-ray...
We quantify the mechanisms for manganese (Mn) diffusion through graphene in Mn/graphene/Ge (001) and Mn/graphene/GaAs heterostructures samples prepared by layer transfer versus growth directly on semiconductor substrate. These are important applications spintronics; however, challenges synthesizing technologically substrates such as GaAs necessitate anneal steps, which introduce defects into graphene. \textit{In-situ} photoemission spectroscopy measurements reveal that Mn grown a Ge...
Understanding the sticking coefficient $\sigma$, i.e., probability of an adatom to a surface, is essential for controlling stoichiometry during epitaxial film growth. However, $\sigma$ on monolayer graphene-covered surfaces and its impact remote epitaxy are not understood. Here, using molecular-beam (MBE) growth magnetic shape memory alloy Ni$_2$MnGa, we show that coefficients metals MgO (001) less than one temperature element dependent, as revealed by ion backscattering spectrometry (IBS)...
The epitaxial growth of functional materials using a substrate with graphene layer is highly desirable method for improving structural quality and obtaining free-standing nano-membranes scientific study, applications, economical reuse substrates. However, the aggressive oxidizing conditions typically employed to grow perovskite oxides can damage graphene. Here, we demonstrate technique based on hybrid molecular beam epitaxy that does not require an independent oxygen source achieve complex...