Perpendicular Emission, Dichroism, and Energy Dependence in Angle-Resolved Photoemission: The Importance of The Final State

Dauth, Matthias; Graus, M.; Schelter, Ingo; Wießner, M.; Schöll, A.; Reinert, F.; Kümmel, Stephan

doi:10.1103/physrevlett.117.183001

Cited by 42 publications

(25 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The choice of the final state ψ f of the photoemission process is crucial when evaluating Eq. (2) [52]. The simplest approximation for the final state is a plane wave [20,53].…”

Section: Photoemission Intensitiesmentioning

confidence: 99%

Understanding the photoemission distribution of strongly interacting two-dimensional overlayers

et al. 2017

View full text Add to dashboard Cite

Photoemission tomography (PT), the analysis of the photoemission intensity distribution within the plane wave final-state approximation, is being established as a useful tool for extracting the electronic and geometric structure of weakly interacting organic overlayers. Here we present a simple method for extending PT, which until now has been based on the calculations of isolated molecules. By including the substrate and a damped plane-wave final state, we are able to simulate the photoemission intensity distribution of two-dimensional molecular overlayers with both strong intermolecular and molecule-substrate interactions, here demonstrated for the model system 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) on Cu(100). It is shown that the interaction and hybridization of the lowest unoccupied molecular orbital of PTCDA with substrate states leads to its occupation and the formation of a strongly dispersing intermolecular band, whose experimental magnitude of 1.1 eV and k-space periodicity is well reproduced theoretically.

show abstract

“…The choice of the final state ψ f of the photoemission process is crucial when evaluating Eq. (2) [52]. The simplest approximation for the final state is a plane wave [20,53].…”

Section: Photoemission Intensitiesmentioning

confidence: 99%

Understanding the photoemission distribution of strongly interacting two-dimensional overlayers

et al. 2017

View full text Add to dashboard Cite

show abstract

“…a plane wave). Both validity of the plane-wave approximation 9–11 and the quantum mechanical interpretation 12 have been discussed in the past. The method was successfully used for the reconstruction of molecular orbitals of polycyclic aromatic molecules solely from ARPES data 8,13–15 .…”

Section: Introductionmentioning

confidence: 99%

Combined orbital tomography study of multi-configurational molecular adsorbate systems

et al. 2019

View full text Add to dashboard Cite

Molecular reactivity is determined by the energy levels and spatial extent of the frontier orbitals. Orbital tomography based on angle-resolved photoelectron spectroscopy is an elegant method to study the electronic structure of organic adsorbates, however, it is conventionally restricted to systems with one single rotational domain. In this work, we extend orbital tomography to systems with multiple rotational domains. We characterise the hydrogen evolution catalyst Co-pyrphyrin on an Ag(110) substrate and compare it with the empty pyrphyrin ligand. In combination with low-energy electron diffraction and DFT simulations, we fully determine adsorption geometry and both energetics and spatial distributions of the valence electronic states. We find two states close to the Fermi level in Co-pyrphyrin with Co character that are not present in the empty ligand. In addition, we identify several energetically nearly equivalent adsorption geometries that are important for the understanding of the electronic structure. The ability to disentangle and fully elucidate multi-configurational systems renders orbital tomography much more useful to study realistic catalytic systems.

show abstract

“…In the last decade, orbital tomography has emerged as an exciting extension of the photoemission technique for imaging localized electronic wave functions in thin film molecules [5][6][7][8][9] . In this framework, the photoemission process can be described either in a one-step model where the final state is represented by a plane wave or using more sophisticated final state approximations [10][11][12][13] . Although the phase of the electronic wave function is not an observable, it can be retrieved under suitable experimental conditions 14 , or by use of iterative algorithms traditionally employed in coherent diffraction imaging 15,16 .…”

Section: Introductionmentioning

confidence: 99%

Ultrafast molecular orbital tomography of a pentacene thin film using time-resolved momentum microscopy at a free-electron laser

Scholz¹,

Baumgärtner²,

Metzger³

et al. 2020

Preprint

View full text Add to dashboard Cite

Understanding and control of photon-induced dynamics of molecules on solid surfaces, including atomic rearrangements as well as charge transfer and non-equilibrium electron dynamics, are of essential importance for surface chemistry but also for the development of new devices. We use time-resolved momentum microscopy at a free-electron laser (FEL) and extend orbital tomography to time-resolved imaging of electronic wave functions of excited molecular orbitals. This technique will provide unprecedented insight into the ultrafast interplay between structural and electronic dynamics. In this work we prove general applicability and establish the experimental conditions at FEL sources to minimize space charge effects and radiation damage. We investigate a bilayer pentacene film on Ag(110) by optical laser pump and FEL probe experiments. From the momentum microscopy signal, we obtain time-dependent momentum maps of the molecular valence states that can be related to the molecular initial states by simulations of the involved photoemission matrix elements. A state above the Fermi level is identified which is temporarily occupied after optical excitation.

show abstract

Perpendicular Emission, Dichroism, and Energy Dependence in Angle-Resolved Photoemission: The Importance of The Final State

Cited by 42 publications

References 62 publications

Understanding the photoemission distribution of strongly interacting two-dimensional overlayers

Understanding the photoemission distribution of strongly interacting two-dimensional overlayers

Combined orbital tomography study of multi-configurational molecular adsorbate systems

Ultrafast molecular orbital tomography of a pentacene thin film using time-resolved momentum microscopy at a free-electron laser

Contact Info

Product

Resources

About