Related Experiment Video
Updated: Aug 9, 2026

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers
Published on: September 27, 2018
Indication of charge-density-wave formation in Bi(111)
Christian R Ast1, Hartmut Höchst
1Synchrotron Radiation Center, University of Wisconsin-Madison, Stoughton, Wisconsin 53589, USA.
Abstract:
Photoemission spectroscopy of Bi(111) reveals a small hexagonal two-dimensional Fermi surface (FS) associated with an electron band centered in the surface Brillouin zone. Along the hexagon the Fermi momentum k(F) ranges from 0.053 to 0.061 A(-1). Temperature dependent valence band spectra show an anisotropic energy gap Delta near the Fermi level. We find a transition temperature of about 75 K. At 11 K, the gap is Delta=4 meV at the corner and Delta=7.5 meV at the side of the hexagon. Arguments based on susceptibility chi(--> q) calculations of a hexagonal FS are used to discuss an incommensurate charge-density-wave (CDW) formation associated with a q(CDW)=0.106 A(-1).
More Related Videos
06:57Theoretical Calculation and Experimental Verification for Dislocation Reduction in Germanium Epitaxial Layers with Semicylindrical Voids on Silicon
Published on: July 17, 2020
13:56Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Related Concept Videos
The de Broglie Wavelength
Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
Valence Bond Theory
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
The Electrical Double Layer