Chapter 9
Hybridized Bonding
Abstract Atoms of electronegative elements such as F, O, N and S bond to atoms of
lower electronegativity form new chemical bonds with an association of positivelycharged holes, nonbonding lone pairs, and antibonding dipoles, which modifies the
valence band by introducing additionally four DOS features. The derived DOS features are detectable using STS (around E F ), IPES (inverse PES, E > E F ), and PES
(E < E F ). New bond formation also modifies the crystal potential and hence results
in further core-level entrapment. The polarization will in turn screen and split the
potential to add excessive features to the core band. Atomic undercoordination and
orbital hybridization enhance each other on the nonbonding electron polarization that
fosters the monolayer high-T C and topological insulator edge superconductivity.
Highlights
• The sp-orbital hybridization results in four excessive valence states.
• Adsorbate-host bond formation further deepens the core levels and adds bonding
states.
• Electron-hole pair production opens the band gap; dipole formation lowers the
work function.
• Spin-resolved polarization by atomic undercoordination and orbital hybridization
foster the high-T C and topological superconductivity.
9.1 STS and IPES: Antibonding and Nonbonding States
The antibonding and nonbonding states are located at energies near E F , which can be
detectable using STS and IPES (inverse photoemission). An STS probes the on-site
DOS of a few atoms across at a surface [1, 2]. Features below E F (sample negative
bias) correspond to the occupied DOS of nonbonding states while features above E F
(sample positive) represent the allowed, yet to be occupied by the antibonding DOS
[3]. Current flows across the barriers or the gap between the STS tip and sample
from the negative to the positive direction. The IPES also probes the occupation of
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_9
181
Hybridized Bonding
Abstract Atoms of electronegative elements such as F, O, N and S bond to atoms of
lower electronegativity form new chemical bonds with an association of positivelycharged holes, nonbonding lone pairs, and antibonding dipoles, which modifies the
valence band by introducing additionally four DOS features. The derived DOS features are detectable using STS (around E F ), IPES (inverse PES, E > E F ), and PES
(E < E F ). New bond formation also modifies the crystal potential and hence results
in further core-level entrapment. The polarization will in turn screen and split the
potential to add excessive features to the core band. Atomic undercoordination and
orbital hybridization enhance each other on the nonbonding electron polarization that
fosters the monolayer high-T C and topological insulator edge superconductivity.
Highlights
• The sp-orbital hybridization results in four excessive valence states.
• Adsorbate-host bond formation further deepens the core levels and adds bonding
states.
• Electron-hole pair production opens the band gap; dipole formation lowers the
work function.
• Spin-resolved polarization by atomic undercoordination and orbital hybridization
foster the high-T C and topological superconductivity.
9.1 STS and IPES: Antibonding and Nonbonding States
The antibonding and nonbonding states are located at energies near E F , which can be
detectable using STS and IPES (inverse photoemission). An STS probes the on-site
DOS of a few atoms across at a surface [1, 2]. Features below E F (sample negative
bias) correspond to the occupied DOS of nonbonding states while features above E F
(sample positive) represent the allowed, yet to be occupied by the antibonding DOS
[3]. Current flows across the barriers or the gap between the STS tip and sample
from the negative to the positive direction. The IPES also probes the occupation of
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_9
181