2013 Fiscal Year Final Research Report

Synthesis of p-type transparent conductive Ti-oxides based films utilizing interface reaction

Research Project

Project/Area Number	25600040
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Single-year Grants
Research Field	Nanomaterials engineering
Research Institution	Osaka University
Principal Investigator	ITO Kazuhiro 大阪大学, 接合科学研究所, 教授 (60303856)
Co-Investigator(Renkei-kenkyūsha)	大西隆神鋼リサーチ株式会社
Project Period (FY)	2013-04-01 – 2014-03-31
Keywords	透明導電膜 / Ti基酸化物 / p型伝導 / 界面反応
Research Abstract	We recently found that an amorphous Ti oxide layer consisting of mainly TiO2 forming at the interface between Cu(Ti) and ITO would be a p-type transparent conductive film in the previous study on contact resistance at the Cu(Ti)/ITO junction. Thus, purpose of the present study is to develop a synthesis of the reaction film on glass substrates and to characterize its optical and electrical properties. Cu(10 at.%Ti) alloy films were deposited on 40 nm-thick ITO/Glass substrates. The Cu(Ti)/ITO/Glass samples were annealed in ultrahigh vacuum at 400C for 6 h. The amorphous Ti-oxide layer with about 20 nm in thickness formed on the glass substrate, and the ITO layer was eliminated due to the reaction. The amorphous Ti-oxide films exhibited transmittance of about 70% in visible light region, sheet resistance of about 1.0 x 10^3 ohm/sq., positive Hall coefficient, and carrier density of about 1.0 x 10^22 cm^-3 at RT. The univalent cation Cu+ would be essential for the p-type conductivity.