Universität zu Köln

Ulstrup, Soren ORCID: 0000-0001-5922-4488, Johannsen, Jens Christian, Cilento, Federico ORCID: 0000-0002-4121-1694, Crepaldi, Alberto ORCID: 0000-0001-9971-1731, Miwa, Jill A., Zacchigna, Michele ORCID: 0000-0002-3785-8823, Cacho, Cephise ORCID: 0000-0002-0058-5817, Chapman, Richard T., Springate, Emma ORCID: 0000-0002-9121-3698, Fromm, Felix, Raidel, Christian, Seyller, Thomas, King, Phil D. C., Parmigiani, Fulvio, Grioni, Marco and Hofmann, Philip ORCID: 0000-0002-7367-5821 (2015). Ramifications of optical pumping on the interpretation of time-resolved photoemission experiments on graphene. J. Electron Spectrosc. Relat. Phenom., 200. S. 340 - 347. AMSTERDAM: ELSEVIER SCIENCE BV. ISSN 1873-2526

Full text not available from this repository.

Abstract

In pump-probe time and angle-resolved photoemission spectroscopy (TR-ARPES) experiments the presence of the pump pulse adds a new level of complexity to the photoemission process in comparison to conventional ARPES. This is evidenced by pump-induced vacuum space-charge effects and surface photovoltages, as well as multiple pump excitations due to internal reflections in the sample-substrate system. These processes can severely affect a correct interpretation of the data by masking the out-of-equilibrium electron dynamics intrinsic to the sample. In this study, we show that such effects indeed influence TR-ARPES data of graphene on a silicon carbide (SiC) substrate. In particular, we find a time- and laser fluence-dependent spectral shift and broadening of the acquired spectra, and unambiguously show the presence of a double pump excitation. The dynamics of these effects is slower than the electron dynamics in the graphene sample, thereby permitting us to deconvolve the signals in the time domain. Our results demonstrate that complex pump-related processes should always be considered in the experimental setup and data analysis. (C) 2015 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Ulstrup, Soren UNSPECIFIED orcid.org/0000-0001-5922-4488 UNSPECIFIED Johannsen, Jens Christian UNSPECIFIED UNSPECIFIED UNSPECIFIED Cilento, Federico UNSPECIFIED orcid.org/0000-0002-4121-1694 UNSPECIFIED Crepaldi, Alberto UNSPECIFIED orcid.org/0000-0001-9971-1731 UNSPECIFIED Miwa, Jill A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Zacchigna, Michele UNSPECIFIED orcid.org/0000-0002-3785-8823 UNSPECIFIED Cacho, Cephise UNSPECIFIED orcid.org/0000-0002-0058-5817 UNSPECIFIED Chapman, Richard T. UNSPECIFIED UNSPECIFIED UNSPECIFIED Springate, Emma UNSPECIFIED orcid.org/0000-0002-9121-3698 UNSPECIFIED Fromm, Felix UNSPECIFIED UNSPECIFIED UNSPECIFIED Raidel, Christian UNSPECIFIED UNSPECIFIED UNSPECIFIED Seyller, Thomas UNSPECIFIED UNSPECIFIED UNSPECIFIED King, Phil D. C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Parmigiani, Fulvio UNSPECIFIED UNSPECIFIED UNSPECIFIED Grioni, Marco UNSPECIFIED UNSPECIFIED UNSPECIFIED Hofmann, Philip UNSPECIFIED orcid.org/0000-0002-7367-5821 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-409096
DOI:	10.1016/j.elspec.2015.04.010
Journal or Publication Title:	J. Electron Spectrosc. Relat. Phenom.
Volume:	200
Page Range:	S. 340 - 347
Date:	2015
Publisher:	ELSEVIER SCIENCE BV
Place of Publication:	AMSTERDAM
ISSN:	1873-2526
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language CARRIER MULTIPLICATION; SPECTROSCOPY; SURFACE Multiple languages Spectroscopy Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/40909