SPECTROSCOPIC RESPONSE OF PHOTOINDUCED CURRENTS IN A LASER-ASSISTED SCANNING TUNNELING MICROSCOPE

Citation
Av. Bragas et al., SPECTROSCOPIC RESPONSE OF PHOTOINDUCED CURRENTS IN A LASER-ASSISTED SCANNING TUNNELING MICROSCOPE, Journal of applied physics, 82(9), 1997, pp. 4153-4158
Citations number
16
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
00218979
Volume
82
Issue
9
Year of publication
1997
Pages
4153 - 4158
Database
ISI
SICI code
0021-8979(1997)82:9<4153:SROPCI>2.0.ZU;2-2
Abstract
Thermal expansion of the sample or tip in a laser-assisted scanning tu nneling microscope (STM) junction can obstruct the study of other phen omena related with STM-light interactions, when photoinduced currents are analyzed. In this article, we show that the thermal contribution i s proportional to the average tunneling current and that this can be u sed to distinguish it from other contributions. Simultaneous tunneling current-voltage and photoinduced current-voltage curves are recorded for highly oriented pyrolitic graphite and gold samples with a Pt tip. We have done the measurements for two different polarizations of the incident beam. We show that the I-V curves can be used to discriminate between different mechanisms that appear, producing photoinduced curr ents. (C) 1997 American Institute of Physics. [S0021-8979(97)05021-4].