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In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx
Published on: May 13, 2020
Microscopic origin of electron accumulation in In2O3
K H L Zhang1, R G Egdell, F Offi
1Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, United Kingdom.
Physical Review Letters
|February 19, 2013
Summary
Angle-resolved photoemission spectroscopy identified a 2D electron gas at the In(2)O(3)(111) surface. Surface oxygen vacancies are the source of electrons, crucial for transparent conducting oxide devices.
Area of Science:
- Materials Science
- Surface Science
- Condensed Matter Physics
Background:
- Transparent conducting oxides (TCOs) are essential for electronic devices.
- Understanding electron accumulation mechanisms in TCOs is critical for device performance.
- Indium oxide (In(2)O(3)) is a promising TCO material.
Purpose of the Study:
- To investigate the origin of the two-dimensional electron gas (2DEG) at the In(2)O(3)(111) surface.
- To elucidate the role of surface states and defects in electron accumulation.
- To provide insights for the development of advanced TCO devices.
Main Methods:
- Angle-resolved photoemission spectroscopy (ARPES) was used to probe surface electronic states.
- Coupled Poisson-Schrödinger calculations were performed to model the electronic band structure.
- Surface defect analysis was conducted to identify the source of charge carriers.
Main Results:
- ARPES confirmed the existence of a 2DEG at the In(2)O(3)(111) surface with quantized subband states.
- Calculations indicated significant downward band bending in the conduction band compared to the valence band.
- Surface oxygen vacancies were identified as the primary source of free electrons, acting as shallow donors.
Conclusions:
- Surface oxygen vacancies are the origin of electron accumulation and the 2DEG in In(2)O(3)(111).
- This finding is significant for optimizing TCO materials and realizing high-performance electronic devices.
- Understanding these surface phenomena is key to advancing transparent electronics.
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