Publications (2)3.84 Total impact
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Article: Spectroscopic Investigation on the Origin of Photoinduced Carrier Generation in Semiconducting InGaO and InGaZnO Films
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ABSTRACT: We investigated the electronic structures of defective semiconducting InGaO and InGaZnO films using X-ray photoelectron spectroscopy. The defects were created intentionally using an intensive Ar-ion bombardment on the films. After Ar bombardment, a subgap state emerged above the valence band edge, which decreased the band gap to <2 eV, suggesting the possibility of electron−hole pair creation even under visible light illumination. Also, the defect states were found to have metal sp characters, being related to oxygen deficiencies in the n-type semiconducting oxides. Therefore, eliminating the oxygen deficiency in the semiconducting oxide films is essential for preventing the photoinduced degradation in thin-film field effect transistors.06/2010; -
Article: Spectroscopic evidence for limited carrier hopping interaction in amorphous ZnO thin film
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ABSTRACT: The electronic structure of amorphous ZnO film ( a -ZnO) was examined by O K - and Zn L<sub>3</sub> -edge x-ray absorption spectroscopy and valence band photoemission spectroscopy. Comparative studies of a -ZnO and a wurtzite ZnO ( w -ZnO) revealed a decrease in Zn 4s -O 2p hybridization strength and the localization of Zn 4s band as a consequence of local structural disorder, indicating limited electron hopping interactions in a -ZnO. The 0.1 eV higher Fermi-level of a -ZnO compared to w -ZnO suggests that the electrical properties of a -ZnO are different from those in w -ZnO due to structural disorder, even in the absence of impurities or grain boundaries.Applied Physics Letters 01/2010; · 3.84 Impact Factor
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Institutions
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2010
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Sungkyunkwan University
- Department of Physics
Seoul, Seoul, South Korea
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