Strain Dependent Electronic Structure and Band Offset Tuning at Heterointerfaces of ASnO3 (A=Ca, Sr, and Ba) and SrTiO3
| Autor: | Yoshihiko Imanaka, Toshihisa Anazawa, Yusuke Miyata, Ronald Maran, John David Baniecki, Hiroyuki Aso, Takashi Yamazaki, Nagarajan Valanoor, Quentin Van Overmeere, Hiroaki Yamada, Dan Ricinschi, Norifumi Fujimura |
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| Rok vydání: | 2017 |
| Předmět: |
Multidisciplinary
Materials science Stannate business.industry Band gap 02 engineering and technology Electronic structure 021001 nanoscience & nanotechnology Epitaxy 01 natural sciences Article Band offset Bond length 0103 physical sciences Scanning transmission electron microscopy Optoelectronics Thin film 010306 general physics 0210 nano-technology business |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/srep41725 |
| Popis: | The valence band (VB) electronic structure and VB alignments at heterointerfaces of strained epitaxial stannate ASnO3 (A=Ca, Sr, and Ba) thin films are characterized using in situ X-ray and ultraviolet photoelectron spectroscopies, with band gaps evaluated using spectroscopic ellipsometry. Scanning transmission electron microscopy with geometric phase analysis is used to resolve strain at atomic resolution. The VB electronic structure is strain state dependent in a manner that correlated with a directional change in Sn-O bond lengths with strain. However, VB offsets are found not to vary significantly with strain, which resulted in ascribing most of the difference in band alignment, due to a change in the band gaps with strain, to the conduction band edge. Our results reveal significant strain tuning of conduction band offsets using epitaxial buffer layers, with strain-induced offset differences as large as 0.6 eV possible for SrSnO3. Such large conduction band offset tunability through elastic strain control may provide a pathway to minimize the loss of charge confinement in 2-dimensional electron gases and enhance the performance of photoelectrochemical stannate-based devices. |
| Databáze: | OpenAIRE |
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