Research on polarization-induced resistance switching in ferroelectric polymer ultra-thin films with different electrodes

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K04653
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied materials
• Research Institution: Tokyo University of Science
• Principal Investigator: Okamura Soichiro 東京理科大学, 理学部第一部応用物理学科, 教授 (60224060)
• Co-Investigator(Kenkyū-buntansha): 中嶋 宇史 東京理科大学, 理学部, 助教 (60516483) ; 橋爪 洋一郎 東京理科大学, 理学部第一部応用物理学科, 助教 (50711610)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 分極誘起抵抗変化 / 高分子強誘電体 / 極薄膜 / トーマスフェルミ遮蔽長 / トンネル伝導 / FTJ

Outline of Final Research Achievements

We studied polarization-induced resistance switching in ferroelectric tunneling junction (FTJ) structure. The original point of this study is the use of ferroelectric VDF/TrFE copolymer. As a result, we revealed that the direction of spontaneous polarization induced high/low resistances and resistance ratios depended on the work functions of two electrode materials. When Au and Pt were used as electrode materials, the resistance ratio of 10,000% was achieved. This value was larger than those previously reported in the FTJ structures with ceramic ferroelectrics. We also investigated the properties of FTJ structures with Nb, Ru and high-doped silicon electrodes instead of Pt. Finally, we concluded that asymmetry potential barrier induced at electrode/ferroelectrics interface due to the differences in Thomas-Fermi screening length in electrode materials was the origin of the polarization-induced resistance switching.

Free Research Field

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