Abstract
The development of flexible substrates that are based on organic polymers is of critical importance to display and photovoltaic applications. Flexible substrates offer the advantages of mechanical flexibility, design freedom, optical transparency, lightweight, and cost-effectiveness. A number of inorganic functional coatings on polymers have critical properties such as water impermeability and electronic conductance, which are required for display and photovoltaic applications.
In this study Transparent Conductive Oxide (TCO) films were deposited on a flexible substrate (200mm x 200mm x 188μm) as a function of deposition temperatures using an sintered indium tin oxide target (In2O3 : SnO2 = 90 : 10 wt%) by RF superimposed DC magnetron reactive sputtering method. The influences of the substrate temperature and oxygen partial pressure on the microstructure, surface roughness and electrical properties were studied. The high quality ITO films were deposited at RT with a resistivity of 3.5x10-4Ωcm and the transmittance higher than 90%. Change of structural properties according to the deposition rate and plasma conditions was also observed with XRD, TEM, and XPS. ITO films deposited at RT showed nanocrystalline phases evolved on the amorphous ITO layer. Very flat surface roughness could be obtained at RT, while surface roughness of the films was increased due to the formation of grains over than 100℃. Consequently, high quality ITO films could be prepared by RF sputtering with low deposition rate and at low deposition temperature; a specific resistivity of 3.5.0x10-4Ωcm, and Rrms values of surface roughness about less than 4 nm and 0.5 nm, respectively.
The mechanical failure of brittle oxide and TCO coatings on flexible polymers is a serious issue. The formation of defects, such as cracks and debonding in TCO films may be inevitable in situations in which bend geometries are required, because of the large difference between the elastic properties of TCO and polymers. The initiation and subsequent developments of defects mainly depend on the coating material, thickness, and interfacial adhesion. Thus, it is important to have a clear understanding of the failure behavior of coatings in the case of bend geometries, in order to prevent the destruction of devices in which they are used. Flexibility of ITO films was measured as functions of the bending radius and bending cycle in bend geometries. It will be considered that these experimental results can be applied to the TCO substrate of flexible LCD devices
CV
Personal Data
Name : Sik-Chol, Kwon
Office : Korea Institute of Materials Science (KIMS),
66 Sangnam-dong,
Changwon, Kyungnam, 641-010, Korea
Tel : (055) 280-3551
Fax : (055) 280-3599, 280-3570
Education
Sep. 1973-Aug. 1975 M.S. in Materials Science Engineering, Korea Advanced Institute of Science(KAIS; now KAIST), Seoul, Korea
Sep. 1975-Feb. 1980 Ph.D. in Materials Science Engineering, Korea Advanced
Institute of Science(KAIS), Seoul, Korea
Oversea Research Experience
May 1982-April 1983 Research Associate, Department of Materials
Science and Engineering, UCLA, LA, U.S.A.
July 1996- June1997 Techische University Braunschweig/ Ecole des Mines Nancy
Research Experience
March -Aug.. 1973 : Semiconductor Lab in KIST
Since March 1980 -Now:
1980. 3 - 1985. 2 : Korea Institute of Machinery &Metals Senior Scientist
1985. 3 - 1990. 1 : Korea Institute of Machinery &Metals Lab Head
1990. 2 - 1991. 7 : Korea Institute of Machinery &Metals, Devision Head
1991. 8 - 1992. 8 : Principal Researcher[Lab Head]
1992. 8 - now : Korea Institute of Materials Science(KIMS),
Principal Researcher[Project Leader]
Professional Societies Affiliations
President[2001 -2003] in The Korean Institute of surface Engineering (KISE)
Vice-president[2006-2010] of IUSF(International Union for Surface Finishing
President[2004-2007] of Korea Thermal Spray Association (KoTSA)
Secretary[2006-now] of ISO/TC107/ SC3
Marquis Who‘s Who in Science and Engineering in the Edition of 2010 and 2011.
Executive Directorate[2000 -] in The Korean Institute of Metals & Materials (KIMM)
He has been author or co-author of 131 papers in scientific and technological conferences and 76 papers on journals in English, and filed 35 patents.
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