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Determination of the valence band offsets at HfO 2 /InN(0001) and InN/In 0.3 Ga 0.7 N(0001) heterojunctions using X‐ray photoelectron spectroscopy
Author(s) -
Eisenhardt Anja,
Knübel Andreas,
Schmidt Ralf,
Himmerlich Marcel,
Wagner Joachim,
Schaefer Juergen A.,
Krischok Stefan
Publication year - 2010
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200983544
Subject(s) - heterojunction , valence band , x ray photoelectron spectroscopy , materials science , molecular beam epitaxy , analytical chemistry (journal) , optoelectronics , epitaxy , chemistry , band gap , nanotechnology , nuclear magnetic resonance , layer (electronics) , physics , chromatography
The valence band offset (VBO) at a InN/In 0.3 Ga 0.7 N(0001) as well as HfO 2 /InN(0001) heterojunction is investigated by X‐ray photoelectron spectroscopy using monochromated AlKα radiation. The InN and In 0.3 Ga 0.7 N films were grown using plasma‐assisted molecular beam epitaxy, whereas HfO 2 layers were deposited by plasma‐assisted electron beam evaporation. The VBOs were determined by analysing the core level binding energy and valence band maxima of bulk‐like films as well as of In 0.3 Ga 0.7 N and InN layers covered with 5 nm thick overlayers of InN and HfO 2 , respectively. The resulting VBO values are ∼0.5 eV for the InN/In 0.3 Ga 0.7 N heterojunction and ∼0.9 eV in the case of the HfO 2 /InN heterointerface.