Many of the Commonwealth’s best scientists are involved at the cutting edge of research on the fundamental understanding of the properties of matter, and their application in a wide range of uses. This session will include talks from a range of prestigious speakers including an industry leader and two national academy presidents, on topics as diverse as solar cells, graphene, nanotechnology and condensed matter.
Graphene has captured the attention of the materials community in the past decade since the first detailed study of its physical properties by Novoselov and Geim at Manchester in 2004. Since then, intensive scientific research in graphene has uncovered its superlative properties, which serve as fundamental building blocks for innovation. Graphene’s unique electrical, optical, mechanical and chemical properties have opened up opportunities for applications in fields as diverse as energy generation, flexible electronics, sensing, and composite materials.
Researchers have recently identified other 2D materials with properties similar to graphene but are semiconducting, thus overcoming graphene’s zero band gap that limits it applications in electronics. Transition metal dichalcogenides (TMDs), such as MoS2 and WSe2, are semiconductors with tunable direct bandgaps that depend on the number of atomic layers. Phosphorene, a monolayer of phosphorus atoms with an electronic gap of a few eVs, is another potential candidate for digital applications.
In this talk, I will give an overview of progress in the field, as well as specific examples from our NUS Surface Science Laboratory. We have demonstrated both bottom-up and top-down methods for fabricating 1D graphene nanoribbons with tunable electronic bandgaps, thereby enabling electronic and photonic applications. We use high resolution scanning tunneling microscopy/spectroscopy (STM/STS) to study the atomic structure and intrinsic electronic properties of 2D TMDs monolayers, and fabricate 2D TMD phototransistors with promising photoresponse characteristics. I will also share my perspective on the future of 2D materials in the context of science in the Commonwealth.
Not long ago polymers were regarded as the ideal material for insulating electric cables. This understanding was completely changed with the discovery of conducting polymers and the closely related family of semiconducting organic electronic materials.
The presentation will illustrate the use of semiconducting conjugated materials in LEDs and solar cells.
Conjugated molecular materials and polymers can be blended with electron accepting compounds such as fullerenes to form bulk heterojunction solar cells. The Victorian Organic Solar Cell Consortium (VICOSC) was established to develop printed bulk heterojunction and dye-sensitised solar cells on plastic. The VICOSC group includes researchers from the University of Melbourne (coordinator), Monash University and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing Flagship, working together with industrial partners. Melbourne and CSIRO have concentrated on bulk heterojunction solar cells, while Monash has focused on dye-sensitised and perovskite devices. The presentation will summarise progress in reaching highly efficient small area cells and large area (A4 size) fully printed solar cell modules.
The development of novel materials has been essential to technological revolutions occurred in the past, and is rather essential to solving current societal problems of importance, for example using renewable source of energy and water purification. Scientific research for the development of a novel material from a large set of possibilities can be quite long, challenging and expensive. With advances in computing resources and algorithms of simulating materials at various scales, computational modelling and simulations have become an indispensable and cost-effective tool in understanding materials, prediction of novel materials and complementing experiments in materials development. I will first give an essential idea of first-principles theory and simulations of materials, a methodology that captures the dependence of properties of a material on its structure and chemistry. This is achieved through a quantum mechanical description of motion of electrons in a solid. With an example of ferroelectrics, a class of smart materials, I will demonstrate (a) a multi-scale modelling strategy to connect microscopic information of a material at electronic scale to that necessary to model a device based on it , and (b) prediction of the world’s thinnest known ferroelectric leading to proposal of nano-scale dipolectronic devices. I will finally discuss an integrated computational approach for knowledge-based discovery of materials, in which the existing strengths in materials modelling in the Commonwealth countries and their network can be effectively used to generate and share information, train scientists and collaborate with industry in rapid development of new advanced materials.
Lead image: "Graphene" by AlexanderAlUSDownload calendar
Professor DD Sarma Solid State and Structural Chemistry Unit, Indian Institute of Science
Professor Paul Attfield FRS School of Chemistry, University of Edinburgh
Professor Andrew Wee President, Singapore National Academy of Sciences
Professor Ric Parker FREng Director of Research and Technology, Rolls Royce (UK)
Professor Umesh Waghmare Jawaharlal Nehru Centre for Advanced Scientific Research (India)
Professor Andrew Holmes FRS President, Australian Academy of Science: "Challenges in Printing Organic Solar Cells".
Professor Mark MacLachlan Department of Chemistry, University of British Columbia (Canada)
Professor Gianluigi Botton Materials Science and Engineering, McMaster University (Canada)