A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Unusual oxidation-induced core-level shifts at the HfO2/InP interface
Tekijät: Mäkelä J, Lahti A, Tuominen M, Yasir M, Kuzmin M, Laukkanen P, Kokko K, Punkkinen MPJ, Dong H, Brennan B, Wallace RM
Kustantaja: NATURE PUBLISHING GROUP
Julkaisuvuosi: 2019
Journal: Scientific Reports
Tietokannassa oleva lehden nimi: SCIENTIFIC REPORTS
Lehden akronyymi: SCI REP-UK
Artikkelin numero: ARTN 1462
Vuosikerta: 9
Sivujen määrä: 14
ISSN: 2045-2322
eISSN: 2045-2322
DOI: https://doi.org/10.1038/s41598-018-37518-2
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/39671755
X-ray photoelectron spectroscopy (XPS) is one of the most used methods in a diverse field of materials science and engineering. The elemental core-level binding energies (BE) and core-level shifts (CLS) are determined and interpreted in the XPS. Oxidation is commonly considered to increase the BE of the core electrons of metal and semiconductor elements (i.e., positive BE shift due to O bonds), because valence electron charge density moves toward electronegative O atoms in the intuitive charge-transfer model. Here we demonstrate that this BE hypothesis is not generally valid by presenting XPS spectra and a consistent model of atomic processes occurring at HfO2/InP interface including negative In CLSs. It is shown theoretically for abrupt HfO2/InP model structures that there is no correlation between the In CLSs and the number of oxygen neighbors. However, the P CLSs can be estimated using the number of close O neighbors. First native oxide model interfaces for III-V semiconductors are introduced. The results obtained from ab initio calculations and synchrotron XPS measurements emphasize the importance of complementary analyses in various academic and industrial investigations where CLSs are at the heart of advancing knowledge.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
