Prof. Kunihito KOUMOTO 

Toyota Physical and Chemical Research Institute, JAPAN

Title: Intercalation Complexes for Flexible Thermoelectrics

We have developed an exfoliation-reassembly process to fabricate an n-type TiS₂/organic hybrid film that is either free-standing or formed on a substrate.  The film is mechanically flexible, so that a flexible device/module made of n-type hybrid element and p-type organic element can be fabricated, which would be beneficial for a variety of energy-harvesting applications. The process recently developed for device/module fabrication will be presented and a prototype thin film module will be demonstrated.

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Dr. Naoki OHASHI

Environment and Energy Materials Division
National Institute for Materials Science, JAPAN

Title: Controlling and Characterization of Defects and Interfaces in Ceramics

Point defects in crystals are difficult to see even with atomic resolution microscopes. However, due to development of computer science and simulation software are now enabling us to visualize atomic arrangements and electron density distribution around assumed point defects. Indeed, a lot of theoretical investigations on defect structures in oxides have been performed, but results obtained by theoretical simulations sometimes seems to be inconsistent to the experimental scientists. To bridge the theoretical predictions and experimental observations, it is very important to consider unintentional impurities, as those are not considered in both experiments and calculations. To this context, we have been devoted to correlate concentration of unintentionally doped impurities and properties of oxides and nitrides. For instance, we have paid a lot of attentions to incorporation of hydrogen into oxides to understand the electronic and optical properties of ceramics in more detail.

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Prof. Susan TROLIER-McKINSTRY

Department of Materials Science and Engineering
Pennsylvania State University, USA

Piezoelectric thin films are of increasing interest in low voltage microelectromechanical systems (MEMS) for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. The seminar will discuss how materials are optimized for these applications, as well as examples of the use of piezoelectric films over a wide range of length scales. The key figures of merit for actuators and energy harvesting will be discussed, with emphasis on how to achieve these on practical substrates. For example, control of the domain structure of the ferroelectric material allows the energy harvesting figure of merit for the piezoelectric layer to be increased by factors of 4 – 10. Likewise, control of crystallographic orientation and substrate clamping enables large increases in the figure of merit for actuators. To illustrate the functionality of these films, examples of integration into MEMS structures will also be discussed, including adaptive optics for Xray telescopes, low frequency and non-resonant piezoelectric energy harvesting devices, and piezoelectronic transistors as a potential replacement for CMOS electronics.

Prof. Tseung-Yuen TSENG 

Department of Electronics Engineering
Institute of Electronics
National Chiao-Tung University, TAIWAN

Title: Metal Oxide Resistive Switching Memory: Materials, Properties, and Switching Mechanisms

With the continuously changing landscape of the computer technologies, a new memory type is needed that will be fast, energy efficient and long-lasting. It shall combine the speed of RAM and be non-volatile in the same time. Resistive RAM (RRAM) is one of the most promising candidates in this respect. RRAM has attracted a great deal of attention owing to its potential as a possible replacement for flash memory in next-generation nonvolatile memory applications. A brief summary of binary metal oxide RRAM is given in this review. We discuss the key challenges of the RRAM technology development, including the mechanisms of resistive switching in transition metal oxides, resistive switching materials, device structures, and the origin of the relatively poor reliability such as endurance and retention of the devices. The resistive switching behaviors of the oxide devices heavily depend on the processing parameter, film composition and dopant, crystalline structure, microstructure, surface morphology, film thickness, electrode material and embedded layer. The review of these factors that influence resistive thin film properties based on our work and reported literature is included in the talk.