Materials by Design for Sustainable Energy ApplicationsWhen: Monday, February 06, 2012 at 3:30 pm
Where: DA 114
Speaker: Yiyang Sun
Organization: Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute
Sponsor: Special Physics Colloquium
A sustainable solution to the ever-increasing global energy demands requires developing new materials or optimizing existing materials. The development and optimization are subject to several constraints. For example, the material has to be stable over a long lifetime, easy to synthesize, cost-efficient, and environment-friendly. To facilitate the development, “Materials by Design” has become a very attractive approach, in which state-of-the-art computational tools are used to faithfully predict the properties of novel materials. In this talk, I will exemplify this concept by our recent works, which cover three classes of materials used for solar energy conversion, energy storage and energy-efficient lighting, respectively. As an example of solar cell materials, I will discuss zinc phosphide (Zn3P2), a semiconductor having a band gap of about 1.6 eV. In particular, I will explain the origin of sustained p-type conductivity in this material. Two examples will be given for energy storage applications. One is molecular hydrogen storage by chemisorption and another is high rate-capability anode material for lithium-ion batteries. Lastly, I will discuss a promising material, zinc oxide (ZnO), for blue-light light-emitting diodes (LEDs). Contrary to the case of Zn3P2, p-type doping has long been a bottleneck issue for the practical application of ZnO for LED applications. I will explain the failure of p-type doping using common acceptor dopants.