Vibrational energy flow at stepped H/Si(111)

Phonons, dipoles and screening

Alex Harris, Klaus Kuhnke, Mario Morin, Peter Jakob, Nicholas J. Levinos, Yves J. Chabal

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Direct measurements of interadsorbate vibrational energy flow between Si-H stretching modes on hydrogen-terminated, stepped vicinal H/Si(111) surface have been made. A two-colour picosecond infrared method has been used in which one vibrational mode is pumped by a resonant infrared pulse and other vibrational modes are probed by vibrationally resonant sum frequency generation to observe energy transfer. The surfaces are prepared by chemical etching in HF solutions and have monohydride-terminated (111)-(1 × 1) terraces with average terrace widths of ca. 5 atoms, and dihydride-terminated steps. The results confirm that interadsorbate energy transfer competes efficiently with slow multiphonon energy relaxation to the substrate. The energy flow is analysed to give a kinetic model of the energy equilibration pathways. The model confirms that the fast relaxing dihydride-terminated steps (60-120 ps lifetime) drain a large fraction (ca. 2/3) of the terrace Si-H mode energy (the terrace mode intrinsic lifetime is fit to be ca. 1.4 ns). The model is consistent with terrace-step energy transfer by dipole-dipole coupling between Si-H oscillators. The dipole coupling also causes normal-mode delocalization, and unusual spectroscopic changes in pump-probe experiments.

Original languageEnglish
Pages (from-to)217-226
Number of pages10
JournalFaraday Discussions
Volume96
DOIs
Publication statusPublished - 1993

Fingerprint

Phonons
Energy transfer
Screening
phonons
screening
dipoles
dihydrides
Infrared radiation
energy transfer
vibration mode
Stretching
energy
Hydrogen
Etching
Natural frequencies
life (durability)
Pumps
Color
Atoms
Kinetics

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Vibrational energy flow at stepped H/Si(111) : Phonons, dipoles and screening. / Harris, Alex; Kuhnke, Klaus; Morin, Mario; Jakob, Peter; Levinos, Nicholas J.; Chabal, Yves J.

In: Faraday Discussions, Vol. 96, 1993, p. 217-226.

Research output: Contribution to journalArticle

Harris, Alex ; Kuhnke, Klaus ; Morin, Mario ; Jakob, Peter ; Levinos, Nicholas J. ; Chabal, Yves J. / Vibrational energy flow at stepped H/Si(111) : Phonons, dipoles and screening. In: Faraday Discussions. 1993 ; Vol. 96. pp. 217-226.
@article{655861d7ce9b4b14b245cf232ea314cd,
title = "Vibrational energy flow at stepped H/Si(111): Phonons, dipoles and screening",
abstract = "Direct measurements of interadsorbate vibrational energy flow between Si-H stretching modes on hydrogen-terminated, stepped vicinal H/Si(111) surface have been made. A two-colour picosecond infrared method has been used in which one vibrational mode is pumped by a resonant infrared pulse and other vibrational modes are probed by vibrationally resonant sum frequency generation to observe energy transfer. The surfaces are prepared by chemical etching in HF solutions and have monohydride-terminated (111)-(1 × 1) terraces with average terrace widths of ca. 5 atoms, and dihydride-terminated steps. The results confirm that interadsorbate energy transfer competes efficiently with slow multiphonon energy relaxation to the substrate. The energy flow is analysed to give a kinetic model of the energy equilibration pathways. The model confirms that the fast relaxing dihydride-terminated steps (60-120 ps lifetime) drain a large fraction (ca. 2/3) of the terrace Si-H mode energy (the terrace mode intrinsic lifetime is fit to be ca. 1.4 ns). The model is consistent with terrace-step energy transfer by dipole-dipole coupling between Si-H oscillators. The dipole coupling also causes normal-mode delocalization, and unusual spectroscopic changes in pump-probe experiments.",
author = "Alex Harris and Klaus Kuhnke and Mario Morin and Peter Jakob and Levinos, {Nicholas J.} and Chabal, {Yves J.}",
year = "1993",
doi = "10.1039/FD9939600217",
language = "English",
volume = "96",
pages = "217--226",
journal = "Faraday Discussions",
issn = "1364-5498",
publisher = "Royal Society of Chemistry",

}

TY - JOUR

T1 - Vibrational energy flow at stepped H/Si(111)

T2 - Phonons, dipoles and screening

AU - Harris, Alex

AU - Kuhnke, Klaus

AU - Morin, Mario

AU - Jakob, Peter

AU - Levinos, Nicholas J.

AU - Chabal, Yves J.

PY - 1993

Y1 - 1993

N2 - Direct measurements of interadsorbate vibrational energy flow between Si-H stretching modes on hydrogen-terminated, stepped vicinal H/Si(111) surface have been made. A two-colour picosecond infrared method has been used in which one vibrational mode is pumped by a resonant infrared pulse and other vibrational modes are probed by vibrationally resonant sum frequency generation to observe energy transfer. The surfaces are prepared by chemical etching in HF solutions and have monohydride-terminated (111)-(1 × 1) terraces with average terrace widths of ca. 5 atoms, and dihydride-terminated steps. The results confirm that interadsorbate energy transfer competes efficiently with slow multiphonon energy relaxation to the substrate. The energy flow is analysed to give a kinetic model of the energy equilibration pathways. The model confirms that the fast relaxing dihydride-terminated steps (60-120 ps lifetime) drain a large fraction (ca. 2/3) of the terrace Si-H mode energy (the terrace mode intrinsic lifetime is fit to be ca. 1.4 ns). The model is consistent with terrace-step energy transfer by dipole-dipole coupling between Si-H oscillators. The dipole coupling also causes normal-mode delocalization, and unusual spectroscopic changes in pump-probe experiments.

AB - Direct measurements of interadsorbate vibrational energy flow between Si-H stretching modes on hydrogen-terminated, stepped vicinal H/Si(111) surface have been made. A two-colour picosecond infrared method has been used in which one vibrational mode is pumped by a resonant infrared pulse and other vibrational modes are probed by vibrationally resonant sum frequency generation to observe energy transfer. The surfaces are prepared by chemical etching in HF solutions and have monohydride-terminated (111)-(1 × 1) terraces with average terrace widths of ca. 5 atoms, and dihydride-terminated steps. The results confirm that interadsorbate energy transfer competes efficiently with slow multiphonon energy relaxation to the substrate. The energy flow is analysed to give a kinetic model of the energy equilibration pathways. The model confirms that the fast relaxing dihydride-terminated steps (60-120 ps lifetime) drain a large fraction (ca. 2/3) of the terrace Si-H mode energy (the terrace mode intrinsic lifetime is fit to be ca. 1.4 ns). The model is consistent with terrace-step energy transfer by dipole-dipole coupling between Si-H oscillators. The dipole coupling also causes normal-mode delocalization, and unusual spectroscopic changes in pump-probe experiments.

UR - http://www.scopus.com/inward/record.url?scp=33645876353&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645876353&partnerID=8YFLogxK

U2 - 10.1039/FD9939600217

DO - 10.1039/FD9939600217

M3 - Article

VL - 96

SP - 217

EP - 226

JO - Faraday Discussions

JF - Faraday Discussions

SN - 1364-5498

ER -