Van Der Waals Epitaxy of GaSe on WSe2

1992 ◽  
Vol 263 ◽  
Author(s):  
O. Lang ◽  
R. Schlaf ◽  
Y. Tomm ◽  
C. Pettenkofer ◽  
W. Jaegermann
Keyword(s):  
Electron Diffraction ◽  
Photoelectron Spectroscopy ◽  
Van Der Waals ◽  
Low Energy ◽  
Scanning Tunneling ◽  
X Ray Diffraction ◽  
Tunneling Microscopy ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron

ABSTRACTGaSe layers were grown on the van der Waals (0001) planes of WSe2 (van der Waals epitaxy). The substrate (0001) plane was cleaned in UHV by heating to 400°C. GaSe was deposited from resistively heated Knudsen cells at T=300° C. After annealing at 450°C an epitaxial GaSe overlayer is formed as evidenced by X-ray diffraction, scanning tunneling microscopy, low energy electron diffraction and photoelectron spectroscopy.

COMBINED HRLEED AND STM INVESTIGATIONS ON THE INITIAL STAGES OF Cu HETEROEPITAXY Ru(0001)

1997 ◽  
Vol 04 (06) ◽  
pp. 1167-1171 ◽  
Author(s):  
CH. AMMER ◽  
K. MEINEL ◽  
H. WOLTER ◽  
A. BECKMANN ◽  
H. NEDDERMEYER
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Strain Relaxation ◽  
Local Scale ◽  
Low Energy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
Layer Structures ◽  
Low Energy Electron

Recent scanning tunneling microscopy (STM) observations revealed different layer structures in the heteroepitaxial Cu/Ru(0001) system with increasing film thickness attributed to various stages of strain relaxation. High-resolution low-energy electron diffraction (HRLEED) analysis permits one to derive more exactly both lattice periodicities and lattice rotations. Furthermore, the representative character of local STM results can be proved. However, STM measurements are needed to identify and to assign the satellite spots to coexistent different superstructures which are superposed incoherently in the diffraction pattern. Generally, the integral LEED results confirm the crystallographic data obtained by STM in a local scale.

scholarly journals Lateral ordering of PTCDA on the clean and the oxygen pre-covered Cu(100) surface investigated by scanning tunneling microscopy and low energy electron diffraction

2014 ◽  
Vol 10 ◽  
pp. 2055-2064 ◽  
Author(s):  
Stefan Gärtner ◽  
Benjamin Fiedler ◽  
Oliver Bauer ◽  
Antonela Marele ◽  
Moritz M Sokolowski
Keyword(s):  
Electron Diffraction ◽  
Scanning Tunneling Microscopy ◽  
Low Energy ◽  
Energy Electron ◽  
Scanning Tunneling ◽  
Structure Model ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Lattice Planes

We have investigated the adsorption of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) on the clean and on the oxygen pre-covered Cu(100) surface [referred to as (√2 × 2√2)R45° – 2O/Cu(100)] by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). Our results confirm the (4√2 × 5√2)R45° superstructure of PTCDA/Cu(100) reported by A. Schmidt et al. [J. Phys. Chem. 1995, 99,11770–11779]. However, contrary to Schmidt et al., we have no indication for a dissociation of the PTCDA upon adsorption, and we propose a detailed structure model with two intact PTCDA molecules within the unit cell. Domains of high lateral order are obtained, if the deposition is performed at 400 K. For deposition at room temperature, a significant density of nucleation defects is found pointing to a strong interaction of PTCDA with Cu(100). Quite differently, after preadsorption of oxygen and formation of the (√2 × 2√2)R45° – 2O/Cu(100) superstructure on Cu(100), PTCDA forms an incommensurate monolayer with a structure that corresponds well to that of PTCDA bulk lattice planes.

Sign in / Sign up

Export Citation Format

Share Document