Polaron character of the near-EF band of cleaved In2O3(111) single crystals
1 Institut für Physik, Humboldt-Universität zu Berlin - Newtonstraße 15, 12489 Berlin, Germany
2 Leibniz-Institut für Kristallzüchtung - Max-Born-Str. 2, Berlin, Germany
Received: 6 January 2016
Accepted: 22 January 2016
The near-EF band of the in situ cleaved (111) surface of high-quality n-type In2O3 single crystals was investigated by high-resolution angle-resolved photoemission (ARPES) along the major symmetry lines of the three-dimensional Brillouin zone. Several criteria to pin down Fermi level crossings and Fermi momenta were applied. The near-EF band is of three-dimensional character connected to the bottom of the conduction band. Since the model of a degenerate semiconductor due to high n-type doping is not sufficient the interaction of electron and phonon degrees of freedom is discussed. It is found that the model of Landau-Pekar polarons is capable of describing the observed lineshape qualitatively and the bandwidth of the occupied part of the conduction band quantitatively.
PACS: 68.47.Fg – Semiconductor surfaces / 71.38.-k – Polarons and electron-phonon interactions / 79.60.-i – Photoemission and photoelectron spectra
© EPLA, 2016