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DC Field | Value | Language |
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dc.contributor.author | Kim, Seong Hwan | - |
dc.contributor.author | Kim, Hye Ju | - |
dc.contributor.author | Lee, Sang Woon | - |
dc.date.issued | 2019-01-01 | - |
dc.identifier.issn | 2369-8128 | - |
dc.identifier.uri | https://aurora.ajou.ac.kr/handle/2018.oak/36483 | - |
dc.identifier.uri | https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85075120606&origin=inward | - |
dc.description.abstract | Recently, oxide heterostructure-based two-dimensional electron gas (2DEG) has received intensive attentions owing to their interesting properties. The model system is epitaxial LaAlO3 (LAO) grown on single crystalline SrTiO3 (STO) substrate.[1] Electrons with a density of 1013~1014/cm2 were observed which moves freely along in-plane direction while they are confined within ~2 nm (out-of-plane direction). Unfortunately, the adjustment of electron density was not available for the epitaxial LAO/STO heterostructure. In addition, the growth of epitaxial LAO film requires a high-temperature process (700 ~ 800°C) using pulsed laser deposition technique. Here, we demonstrated a creation and control of 2DEG at the interface of non-epitaxial Al2O3/TiO2 thin film heterostructure using atomic layer deposition (ALD). The electron density can be tailored from ~ 1011/cm2 to ~ 1014/cm2 by the control of ALD process temperature because the electrons are coming from oxygen vacancies at the interface of Al2O3/TiO2 heterostructure of which oxygen vacancy density is governed by kinetics during the ALD process. Electron density up to ~1014/cm2 was achieved at the interface of the Al2O3/TiO2 heterostructure which is 100 times higher than that of the conventional semiconductor heterojunction such as AlGaAs/GaAs. The 2DEG at Al2O3/TiO2 heterostructure can be applied for the development hydrogen (H2) gas sensor. A highperformance, transparent, and extremely thin (<15 nm) hydrogen gas sensor was fabricated using 2DEG at the interface of Al2O3/TiO2 heterostructure grown by ALD. [2] Palladium nanoparticles (≈2 nm in thickness) are used on the surface of the Al2O3/TiO2 thin film heterostructure to detect H2. Both oxides with a wide bandgap (>3.2 eV) have transmittance of 83% in the visible spectrum, which allows for a transparent sensor. The Pd/Al2O3/TiO2 gas senor detects H2 gas quickly with a short response time of <30 s even at room temperature which outperforms conventional H2 gas sensors. This sensor responds to a wide range of H2 concentration, especially from ~5 ppm to 1%, implying a promising candidate for a general H2 sensor. Interestingly, the Pd/Al2O3/TiO2 gas senor showed an optimal electron density for H2 detection owing to the tailoring ability of 2DEG at the Al2O3/TiO2 heterostructure. Particularly, a sensitivity was as low as 3% for a 2DEG density of 5.6 × 1013 cm-2 while the sensitivity was improved from 6% to 43% as the electron density decreased from 5.6 × 1013 cm-2 to 4.1 × 1011 cm-2. Besides the sensor application, other application of 2DEG will be introduced in the presentation. | - |
dc.language.iso | eng | - |
dc.publisher | Avestia Publishing | - |
dc.title | Tailoring of two-dimensional electron gas density in thin film oxide heterostructure via atomic layer deposition | - |
dc.type | Conference | - |
dc.citation.conferenceDate | 2019.8.18. ~ 2019.8.20. | - |
dc.citation.conferenceName | 5th World Congress on New Technologies, NEWTECH 2019 | - |
dc.citation.edition | 5th World Congress on New Technologies, NEWTECH 2019 | - |
dc.citation.title | Proceedings of the World Congress on New Technologies | - |
dc.citation.volume | 0 | - |
dc.identifier.bibliographicCitation | Proceedings of the World Congress on New Technologies | - |
dc.identifier.doi | 10.11159/icnfa19.135 | - |
dc.identifier.scopusid | 2-s2.0-85075120606 | - |
dc.identifier.url | avestia.com/NewTech2017_Proceedings/index.html | - |
dc.type.other | Conference Paper | - |
dc.description.isoa | true | - |
dc.subject.subarea | Biotechnology | - |
dc.subject.subarea | Energy Engineering and Power Technology | - |
dc.subject.subarea | Biomedical Engineering | - |
dc.subject.subarea | Electrical and Electronic Engineering | - |
dc.subject.subarea | Mechanical Engineering | - |
dc.subject.subarea | Management, Monitoring, Policy and Law | - |
dc.subject.subarea | Pollution | - |
dc.subject.subarea | Electronic, Optical and Magnetic Materials | - |
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