Presenter: Dr. Takayoshi Katase (Hokkaido University)
Topic: Optoelectronicand electromagnetic switching device with transition metal oxides usingwater-leakage-free electrolyte
Time: 10:00 AM, Oct.10th (Monday)
Location: Conference Room B, BLDG 909-1F
Abstract
Opto-electronic and electro-magneticproperties of transition metal oxides (TMOs) can be modulated by modifyingoxygen concentration and/or protonation due to the valence-state change of TMions. For the application to multifunctional memory device, the functionalityshould be switched at room temperature (RT) by a solid-state device, but theswitching classically needs high-temperature heating or electrochemicalreaction with liquid electrolyte, which is not suitable for practicalapplications. We have proposed a new thin-film-transistor(TFT) structure with water-infiltrated nanoporous glass, amorphous 12CaO-7Al2O3,(CAN), as a gate insulator [1] and have demonstrated electric-field-induced 2dimensional electron gas (2DEG) in SrTiO3 single crystal; the 2DEGlayer with electron carrier density up to ~1015 cm−2 exhibits an unusuallylarge thermopower [2]. For VO2-based TFTs, we haverealized the RT-protonation-driven metal-insulatorphase modulation, leading to the on-demand control of infrared transmittancefor advanced smart windows [3]. For WO3-based TFTs, we have demonstratedan electrochromic metal-insulator switching device, which exhibitsmulti-functionality of electrochromism and electrical-switching byRT-protonation [4]. For SrCoOx-basedTFTs, an antiferromagnetic insulator (AFM-SrCoO2.5) was reversibly controlled to a ferromagnetic metal (FM-SrCoO3) by electrochemical redox reaction at RT [5]. The present device canswitch the functional properties of TMOs at RT by using ‘water-leakage-freeelectrolyte’, which will provide a novel design concept for TMO-based practicalmemory devices.
[1] H. Ohta et al., Nature Commun. 1, 118 (2010), [2] H. Ohta etal., Adv. Mater. 24, 740 (2012), [3] T.Katase et al., Adv. Electron. Mater. 1, 1500063 (2015), [4] T. Katase etal., Adv. Electron. Mater.2, 1600044 (2016), [5] T. Katase et al., Sci. Rep. 6,25819 (2016).
Biography
Dr. Katase is currently AssistantProfessor in the group of Prof. Hiromichi Ohta at Research Institute forElectronic Science at Hokkaido University, Japan. He obtained a B.S. from TokyoInstitute of Technology, Japan in 2007 and a M.S. from Tokyo Institute ofTechnology, Japan in 2009, and a Ph.D. from Tokyo Institute of Technology, Japanin 2012.
Contact:Prof. Steffen Duhm
（责任编辑：张伶 邮箱：zhangling10@suda.edu.cn）
