Premium
Characterizations of bismuth telluride films from Mott‐Schottky plot and spectroscopic ellipsometry
Author(s) -
Zimmer Alexandre,
Stein Nicolas,
Johann Luc,
Terryn Herman,
Boulanger Clotilde
Publication year - 2008
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2715
Subject(s) - bismuth telluride , ellipsometry , materials science , band gap , semiconductor , analytical chemistry (journal) , schottky diode , capacitance , thin film , bismuth , dielectric , dielectric spectroscopy , electrical resistivity and conductivity , chemistry , optoelectronics , electrochemistry , electrode , nanotechnology , diode , seebeck coefficient , electrical engineering , metallurgy , thermal conductivity , engineering , chromatography , composite material
Abstract Capacitance measurement results (via the so‐called Mott‐Schottky plot) and Infrared spectroscopic ellipsometry (IRSE) analysis have been carried out in order to study semiconducting properties of electroplated thin films of bismuth telluride (Bi 2 Te 3 ) without any electrical contact. Electrochemical impedance measurements at 10 kHz exhibited that films characterized n‐type semiconductors, depending upon potentials applied above and below the flat‐band potential. By IRSE study, the energy band gap E g was found to be about 0.11 eV independent of the film composition and the electrical resistivity of about 30 µΩ.m. By combining IRSE and capacitance measurement results, dielectric constant ε and carrier concentration of the samples were calculated without any assumptions. Copyright © 2008 John Wiley & Sons, Ltd.