Chemisorbed-molecule potential-energy surfaces and electronically stimulated processes

Dwight R. Jennison, Ellen Stechel, Alan R. Burns, Y. S. Li

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Three topics illustrate some central physics of processes produced by UV-laser and low-energy electron stimulation. First, a multi-dimensional ground-state potential energy surface (PES) for NH3:Pd(111), computed using ab initio local-density functional theory, allows dramatically different dynamics depending on poorly-known excited-state forces. We use quantum-resolved experimental data to argue that stimulated desorption is dominated by a direct path off the surface, following placement of the wavepacket on a molecule-surface hard wall accessed by internal molecular motion. This illustrates the questionable relevance of 1D models for understanding molecule-surface dynamics. Second, we study the image-charge model of excited state forces experienced by ions produced, for example, by hot carrier attachment. Ab initio results show that this model totally fails at molecule-surface distances typical of chemisorption. Finally, we present a purely-electronic adiabatic model of excited state PESs and use it to argue that, if significant covalent interactions occur between an adsorbate and a surface, hot carrier attachment does not simply produce singly- charged ions. Instead, attachment creates excitation of the molecule-surface bond occur and, in some cases, may result in multiply-charged ions.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsHai-Lung Dai, Steven J. Sibener
PublisherSociety of Photo-Optical Instrumentation Engineers
Pages192-206
Number of pages15
Volume2125
ISBN (Print)0819414182
Publication statusPublished - 1994
EventLaser Techniques for Surface Science - Los Angeles, CA, USA
Duration: Jan 27 1994Jan 29 1994

Other

OtherLaser Techniques for Surface Science
CityLos Angeles, CA, USA
Period1/27/941/29/94

Fingerprint

Potential energy surfaces
potential energy
Molecules
Excited states
attachment
molecules
Hot carriers
excitation
Ions
hot surfaces
ions
Adsorbates
Chemisorption
ultraviolet lasers
stimulation
chemisorption
Ground state
Density functional theory
Desorption
Physics

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Jennison, D. R., Stechel, E., Burns, A. R., & Li, Y. S. (1994). Chemisorbed-molecule potential-energy surfaces and electronically stimulated processes. In H-L. Dai, & S. J. Sibener (Eds.), Proceedings of SPIE - The International Society for Optical Engineering (Vol. 2125, pp. 192-206). Society of Photo-Optical Instrumentation Engineers.

Chemisorbed-molecule potential-energy surfaces and electronically stimulated processes. / Jennison, Dwight R.; Stechel, Ellen; Burns, Alan R.; Li, Y. S.

Proceedings of SPIE - The International Society for Optical Engineering. ed. / Hai-Lung Dai; Steven J. Sibener. Vol. 2125 Society of Photo-Optical Instrumentation Engineers, 1994. p. 192-206.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Jennison, DR, Stechel, E, Burns, AR & Li, YS 1994, Chemisorbed-molecule potential-energy surfaces and electronically stimulated processes. in H-L Dai & SJ Sibener (eds), Proceedings of SPIE - The International Society for Optical Engineering. vol. 2125, Society of Photo-Optical Instrumentation Engineers, pp. 192-206, Laser Techniques for Surface Science, Los Angeles, CA, USA, 1/27/94.
Jennison DR, Stechel E, Burns AR, Li YS. Chemisorbed-molecule potential-energy surfaces and electronically stimulated processes. In Dai H-L, Sibener SJ, editors, Proceedings of SPIE - The International Society for Optical Engineering. Vol. 2125. Society of Photo-Optical Instrumentation Engineers. 1994. p. 192-206
Jennison, Dwight R. ; Stechel, Ellen ; Burns, Alan R. ; Li, Y. S. / Chemisorbed-molecule potential-energy surfaces and electronically stimulated processes. Proceedings of SPIE - The International Society for Optical Engineering. editor / Hai-Lung Dai ; Steven J. Sibener. Vol. 2125 Society of Photo-Optical Instrumentation Engineers, 1994. pp. 192-206
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