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1,114 results on '"Lee, Se Hee"'

212. Gasocrhomic mechanism in a-Wo3 thin films based on Raman spectroscopic studies

Author

Lee, Se-Hee, Cheong, Hyeonsik M., Liu, Ping, Smith, Dave, Edwin Tracy, C., Mascanrenhas, Angelo, Roland Pitts, J., and Deb, Satyen K.

Subjects
Oxides -- Research, Raman spectroscopy -- Usage, Thin films -- Research, Physics
Abstract

Raman scattering measurements were used to investigated the gasochromic mechanism in amorphous tungsten oxide films.

Published
2000

221. Clinical Utility of Quantitative CT Analysis for Fissure Completeness in Bronchoscopic Lung Volume Reduction: Comparison between CT and Chartis™

Author

Lee, Sei Won, primary, Shin, So Youn, additional, Park, Tai Sun, additional, Choi, Yoon Young, additional, Park, Jong Chun, additional, Park, Jina, additional, Oh, Sang Young, additional, Kim, Namkug, additional, Lee, Se Hee, additional, Lee, Jae Seung, additional, Seo, Joon Beom, additional, Oh, Yeon-Mok, additional, Lee, Sang-Do, additional, and Lee, Sang Min, additional

Published
2019
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237. Novel haloarchaeon Natrinema thermophila having the highest growth temperature among haloarchaea with a large genome size

Author

Kim, Yeon Bee, primary, Kim, Joon Yong, additional, Song, Hye Seon, additional, Lee, Changsu, additional, Ahn, Seung Woo, additional, Lee, Se Hee, additional, Jung, Min Young, additional, Rhee, Jin-Kyu, additional, Kim, Juseok, additional, Hyun, Dong-Wook, additional, Bae, Jin-Woo, additional, and Roh, Seong Woon, additional

Published
2018
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241. The effect of thermal annealing on photoelectrochemical responses of WO3 thin films.

Author

Ahn, Kwang-Soon, Lee, Se-Hee, Dillon, Anne C., Tracy, C. Edwin, and Pitts, Roland

Subjects
*SOLAR energy, *PHOTOELECTRIC cells, *PHOTOELECTROCHEMISTRY, *FUSED silica, *POLYCRYSTALS, *SEMICONDUCTORS
Abstract

The photoelectrochemical responses of WO3 thin films have been investigated as a function of annealing temperature up to 600 °C. WO3 films were deposited on unheated substrates by thermal evaporation followed by annealing at temperatures of 300, 500, and 600 °C for 5 h in air. The WO3 film annealed at 500 °C shows the best photoelectrochemical response due to improved crystallinity and enhanced light absorption in the long-wavelength region. Although the WO3 film annealed at 600 °C exhibits better crystallinity and increased light absorption properties, it shows a decreased photoelectrochemical response in comparison to the one annealed at 500 °C. These results strongly suggests that the reduced amount of electrochemical reaction sites for the film annealed at 600 °C film plays a significant role in influencing the decreased photoresponse. [ABSTRACT FROM AUTHOR]

Published
2007
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242. Identification of nitrogen chemical states in N-doped ZnO via x-ray photoelectron spectroscopy.

Author

Perkins, Craig L., Lee, Se-Hee, Li, Xiaonan, Asher, Sally E., and Coutts, Timothy J.

Subjects
*ZINC oxide thin films, *NITROGEN, *VAPOR-plating, *THIN films, *ZINC compounds, *ORGANOMETALLIC compounds
Abstract

Nitrogen-doped films of ZnO grown by two methods, metalorganic chemical vapor deposition (MOCVD) and reactive sputtering, were studied with x-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). Systematic differences in the N chemical states were observed between films grown by sputtering and MOCVD: only two N chemical states were observed in films grown by reactive sputtering, whereas four N chemical states were observed in MOCVD films. To aid in the assignment of the N chemical states, photoemission data from the polycrystalline films were compared with data taken on N2+-implanted Zn metal and N2+-implanted ZnO. High-resolution core level spectra of the N 1s region indicated that nitrogen can occupy at least four different chemical environments in ZnO; these include the NO acceptor, the double donor (N2)O, and two carbon–nitrogen species. Valence band spectra indicate that the Fermi energy of all films studied was near the conduction band minimum, implying that the films remained n-type after nitrogen doping. Analysis of the relative amounts of acceptors and donors identified by XPS in the sputter-grown films provides clues as to why only a small percentage of incorporated nitrogen is found to contribute to carriers, and points toward possible paths to higher quality ZnO:N films. [ABSTRACT FROM AUTHOR]

Published
2005
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243. Microstructure study of amorphous vanadium oxide thin films using raman spectroscopy.

Author

Lee, Se-Hee, Cheong, Hyeonsik M., Je Seong, Maeng, Liu, Ping, Tracy, C. Edwin, Mascarenhas, Angelo, Pitts, J. Roland, and Deb, Satyen K.

Subjects
*VANADIUM pentoxide, *MICROSTRUCTURE, *RAMAN effect, *AMORPHOUS substances, *THIN films
Abstract

Microstructural changes of amorphous V[sub 2]O[sub 5] films with lithium intercalation are studied using Raman-scattering measurements. The Raman spectra of as-deposited films show two broad peaks around at 520 and 650 cm[sup -1], due to the stretching modes of the [sub V]3-O and V[sub 2]-O bonds, respectively, and a relatively sharp peak at 1027 cm[sup -1] due to the V[sup 5+]=O stretching mode of terminal oxygen atoms. In addition, there is a peak at 932 cm[sup -1] that we attribute to the V[sup 4+]=O bonds. Comparison of the Raman spectra of V[sub 2]O[sub 5] films with different oxygen deficiencies confirms this assignment. This Raman peak due to the stretching mode of the V[sup 4+]=O bonds develops and shifts toward lower frequencies with increasing lithium concentration. Comparison to results from gasochromic hydrogen insertion indicates that the 932 cm[sup -1] Raman peak is not a result of vibrations which involve Li or H atoms. We propose that the V[sup 4+]=O bonds are created by two different mechanisms: a direct conversion from V[sup 5+] = O bonds and the breaking of the single oxygen bonds involving V[sup 4+] ions. [ABSTRACT FROM AUTHOR]

Published
2002
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