Dresden 2014 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 69: Emerging oxide semiconductors II (Focus session with DS)
HL 69.3: Vortrag
Mittwoch, 2. April 2014, 15:45–16:00, POT 081
Barrier height of Ag on In2O3 (111) single crystals — •maryam nazarzadehmoafi1, stephan machulik1, florian Neske1, christoph janowitz1, zbigniew galazka2, and recardo manzke1 — 1Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany — 2Leibniz-Institut für Kristallzüchtung, Max-Born-Str. 2, Berlin, Germany
The barrier height of a metal-semiconductor contact was studied by means of angle-resolved photoemission spectroscopy, which was implemented through stepwise Ag deposition on the (111) surface of In2O3 single crystals. Work function of Ag and electron affinity of In2O3 were measured in situ, being 4.21±0.05 eV and 4.24±0.05 eV, respectively. A slight barrier height of 0.15±0.07 eV was determined by following the band bending of valence band and core level spectra with Ag coverage. Good agreement was observed when comparing the results to a calculation of the height by applying the Schottky-Mott rule, yielding the negligible value of 0.03±0.05 eV. Therefore, the character of the contact is ohmic like. Additionally, the results revealed the existence of diffuse band-gap states for In2O3(111) and a Fermi level shift by 0.09 ±0.02 eV due to the photovoltage effect with Ag deposition.