Category: Plenary

Professor George Malliaras
Ecole Nationale Superieure des Mines, France

George Malliaras of Ecole Nationale Superieure des Mines is one of the pioneers in the field of organic electronics and bioelectronics. Due to his excellence of the research, he has been recognized well in this research field.In the Plenary Lecture, Prof. Malliaras gave us an attractive lecture about interfacing with the brain using organic electronics. In the beginning of the lecture, he mentioned that interfacing the most advanced human engineering endeavor with the brain will help elucidate aspects of the brain’s working mechanism and deliver new tools for diagnosis and treatment of a host of pathologies including epilepsy and Parkinson’s disease. He then offered the view that organic semiconductors can be good candidate materials that are brought in contact with the tissue and transduce signal across the biotic/abiotic interface, because several organic semiconductors show a unique combination of attractive properties such as mechanical flexibility, mixed ionic/electronic conduction, enhanced biocompatibility, and capability for drug delivery. He showed excellent examples of novel devices for recording and stimulation of brain activity. Furthermore, he presented that developments in organic electronics offer tremendous opportunities to design devices that improve our understanding of brain physiology and pathology, and can be used to deliver new therapies.

Many audience listened with a lot of attention to his interesting talk. The participants of this lecture were excited at his novel concepts and surprising data.

Professor Andrew Holmes

(President of Australian Academy of Science)

The organic solar cells have attracted much attention from perspective of high efficiency, scale up and low cost production. Professor Holmes showed summary of recent progress in assembling small laboratory-based efficient bulk heterojunction solar cell. Also, he touched some challenges for scale up from laboratory type to industrial application. In addition, the challenge for improvement of reliability and durability was introduced. In his talk, he showed some innovative examples which were already published in first class journal including his own data. His work was good bridge between fundamental and industrial works. His beautiful talk inspired us to see radical innovation in our challenge.

C.N.R. RAO, National Research Professor
Wednesday, August 30, 2017　12:00-12:40

Prof. Rao, National Professor and Linus Pauling Research Professor at the Jawaharlal Nehru Center for Advanced Scientific Research, passionately explained the wonders of the low dimensional nanostructures and the layered 2D materials including MoS2, WS2, GaS, BN, and carbon nitrides and their fascinating properties including high surface area, band gaps and porosity. He beautifully explained how these materials can conquer the world of advanced materials research by offering amazing performance in many applications including energy storage, hydrogen generation, optoelectronic devices, magnetism, superconductivity, and catalysis.

As we all expected, Rao presented several strategies to make a library of new advanced nanostructures. One of the main highlights of his talk is the novel strategies for generating covalently linked heterostructures of different two-dimensional layered materials whose properties are completely different from those of van der Waals heterostructures. By simply using Sonogashira coupling and carbodimide based coupling, his groups generated ladder-like multilayered structures which cannot be prepared by a simple van der Waals interactions. Unique strategies have been presented to fabricate graphene coupled with 1D, 2D and zero dimensional metal organic frameworks. At one point, the audience wondered what materials and the research topic Prof. Rao missed in his talk as he covered the topics including materials chemistry, organic chemistry, physics, theoretical chemistry, nanochemistry, etc. It was absolutely a mesmerizing talk and offered the researchers a pool of novel ideas and venues to work on advancing the nanomaterials research. The performance of these nanostructures have been amazingly demonstrated in hydrogen generation via photocatalytic water splitting, electrocatalysis and heterogeneous catalysis.

On the fundamental side, Prof. Rao presented the interaction of electron donar and acceptor molecules and their relation with the electronic structure and properties of these new class of materials including phospherenes. At the end of the talk, he told the audience that the covalently bonded heterostructures are just the beginning and a lot of new structures to be explored including chalcogenides-chalcogenides, Chalcogenides-nitrides, and/or with arsenene or germanane. These unique materials are going to make a revolution in the field of advanced materials science and energy generation which eventually help to protect the people and economy.

Posted by Prof. Ajayan Vinu, FRSC
Future Industries Institute, University of South Australia

The plenary lecture 4 on carbohoration by Suzuki coupling was delivered by a novel lauriate of professor Suzuki at the Hokaito University, Japan.  And then the plenary lecture 5 on Inorganic Graphene Analogues Recent Results was delivered in the same auditorium by Professor C.N.R. Rao at the Jawaharlal Nehru Centre for Advanced Scientific Research,Bangalore, India.

These two speakers are still healthy even though over 80 years old and still have very strong energy and enthusiasm without aging effect. Professor Rao have carried out research on  materials chemistry on various functional inorganic materials. He described new 2D materials for H₂ evolution as followings:  Several years ago graphene has been a sensational discovery and there are so many publications on graphene and graphene oxide. These nanosheet materials are called 2D materials. Particularly graphene is conductive materials, but not semiconductor. In the last two to three years, there has been effort to prepare graphene-like layered inorganic materials such as MoS2, WS₂, GaS and BN. Several methods of synthesis of such nanosheets have been developed. Some of the recent results on few-layer transit metal chalcogenides(TMC) such as as SnSe, MoSe, WSe, and BN was presented. Specially interesting are the physical properties of these nano materials such as magnetism and superconductivity. Transistors and devices have been fabricated with many of the layered inorganic materials. A new graphene-like material is BxCyNz with high surface area and novel gas adsorptive properties. These materials have other extraordinary properties, their use as electrocatalysts being specially noteworthy. Specially noteworthy are the novel materials obtained by cross linking MoS2 with other 2D materials or by functionalizing MoS2 sheets. Thus, interaction of electron donor and acceptor molecules has unraveled the electronic structure and properties of phospherene. Covalent cross-linking C3N4 and MoS2 favors photochemical splitting of water. TIO2 was very good photocatalytic materials, however, the H2 evolution efficiency was not enough.  2D materials can be made by sonochemistry method  and chemical decomposing, and adding another functional groups by Suzuki coupling method.  This Suzuki coupling method was well introduced by the former plenary speaker.  These 2D nano materials of MoS2, SnSe, graphene and BN can be functionalzed by adding another group such as MOF (metal organic frame materials) between the mono layers of  2D materials by Suzuki coupling method.  These functionalized 2D materials showed the 10 times higher than the current developed semiconductor materials for water splitting.

After the plenary lecture, there was only one question.  It was “What is the chemical bonding between 2D materials and functional groups?  It is a covalent bonding”

Axel Hoffmann, Materials Science Division, Argonne National Laboratory

In his plenary lecture Axel Hoffmann discussed new magnetically ordered structures, which recently have gained much attention due to their potential for low-energy applications.  These magnetic structures are called magnetic skyrmions and this name is derived from the theoretical physicist Tony Skyrme, who originally developed in the 1960’s a theoretical model describing nuclear particles as topological solitons within a vector field.  But similar structures can also form in magnetically ordered materials.  Interestingly, due to their distinct topology these magnetic skyrmions can behave like individual stable particles.

They were first discovered about a decade ago in special magnetic materials at low temperatures, but the work from Axel Hoffmann and his colleagues showed that they can be also stabilized at room temperature in magnetic multilayers of materials that are commonly used for magnetoelectronic applications.  At the same time these magnetic skyrmions can be easily manipulated with even very low electric currents, which makes them of interest for data storage and processing applications.

During his presentation Axel Hoffmann also showed two interesting basic physics concepts.  First he showed that magnetic skyrmions can be formed by using inhomogeneous electric currents.  This process is strikingly similar to common phenomena in surface tension driven fluid flows, such as the formation of soap bubbles by blowing through a suspended soap film.  Second he showed that the twirling magnetic structure of magnetic skyrmions results in “curved” trajectories.  The physics behind this skyrmion Hall effect is very similar to the motion of curveball in baseball or soccer, where the rotation of the ball results in a change of trajectory to confuse the batter or goalkeeper.  This shows that the investigation of magnetic skyrmions is not only fascinating because of their prospect for novel applications, but that their distinct topology also provides new interesting fundamental physical phenomena.

Axel Hoffmann always gives very interesting and valuable presentations, and his lighthearted approach, makes his talks very engaging.  Thus his Plenary Talk offered both an academic and peaceful atmosphere to audience.  As part of his Talk he presented a brief video showing how the Brazilian soccer player Roberto Carlos used a curved ball to leave the French goalkeeper confused.  This gave the audience an easy understanding for difficult physics delivered with humor.  But of course the question arises, whether “the twirling magnetic structure of magnetic skyrmions moving on curved trajectories” confused anybody?  Fortunately Axel Hoffmann addressed any remaining confusion well during the questions and answers.

The helix is ubiquitous in nature, and one of the prevalent structural motifs for biological polymers, playing key roles in their sophisticated functions. Professor Yashima showed unique polymers consisting of preferred-handed helical conformation induced by chiral dopants.  Generally, the polymer lost preferred-handed helical structure when the chiral dopant was removed from the system.  He showed novel helical polymer which remain the preferred-handed helical structure even after removal chiral dopant using specific poly acetylene with well-established side chains.  This memory effect can be utilized for production of separation materials for chiral chemicals and drugs.

Prof. Yashima summarized helicity induction and memory strategy which has a remarkable advantage from a practical viewpoint.  Various examples on the direct observations of helical structures of synthetic helical polymers by atomic force microscopy (AFM) was presented. A series of double and/or multi helices composed of different components and sequences that exhibit specific functions, such as chiral recognition and anisotropic spring-like motion was also introduced　with very impressive images.

The first plenary lecture was given by Nobel Prize Winner, Hiroshi Amano, Director, Center for Integrated Research of Future Electronics, and a Professor, Institute of Materials and Systems for Sustainability, Nagoya University. The Clock Tower Hall was so jam-packed there were so many standing audiences.

The title of his plenary lecture was “Development of Sustainable Smart Society via Transformative Electronics”. At the beginning of the lecture, he demonstrated the mechanism of the generation of white light using the arrays of blue LEDs with a practiced hand. He is proud that the white LEDs in conjunction with solar cells and batteries enable nomadic children of Mongolia to study nights, He emphasized the contribution of the white LED to the reduction of power consumption, His lecture was composed of three parts: AlGaN-based deep ultraviolet LEDs (DUV LED), GaN-based heterojunction field-effect transistors (HFETs) and photocathodes (or electron emitters).
According to UNICEF report in 2015, 663 million people still lack access to safe drinking water and 2.4 billion people do not use safe sanitation facilities. The high-power DUV LEDs have been utilized in commercial water sterilization and purification systems.

He compared the energy losses in photovoltaic power generation to bank transfer fees just for fun. By replacing Si-based power devices with GaN-based power devices, the average efficiency of inverters or converters can be improved from 95% to more than 99%. He said that one of his dreams is to replace the transformers used in Shinkansen train cars by the semiconductor devices completely.
In comparison with the commercial GaAs photocathodes, GaN and InGaN photocathodes have much longer lifetimes and higher quantum yields. He demonstrated that the short high-power pulsed operation is very promising for observing the blurring of moving objects.

All the audiences had a sense of the possibilities for further development of the research on the GaN based devices in the future.