Semiconductor Nanowires for Solar Energy Conversion
Peidong Yang, PhD
Department of Chemistry, Materials Science and Engineering
University of California Materials Science Division
Lawrence Berkeley National Laboratory
ABSTRACT
Semiconductor nanowires represent an important class of nanostructure building block for photovoltaics as well as direct solar-to-fuel application because of their high surface area, tunable bandgap, light trapping capabilities and efficient charge transport and collection. The generation of fuels by the direct conversion of solar energy in a fully integrated system is an attractive goal, but no such system has been demonstrated that shows the required efficiency, is sufficiently durable, or can be manufactured at reasonable cost. It requires major research advancement in the area of semiconductor light absorber and catalyst discovery. One of the most critical issues in solar water splitting is the development of a suitable photoanode with high efficiency and long-term durability in an aqueous and photo-oxidative environment. Nanowires can be readily designed and synthesized to deterministically incorporate heterojunctions with improved light absorption, charge separation and vectorial charge transport. High surface-area nanowire arrays can serve as photocathodes and photoanodes within an artificial photosynthetic system. Meanwhile, it is also possible to selectively decorate different oxidation or reduction catalysts onto specific segments of the nanowires to mimic the compartmentalized reactions in natural photosynthesis. The bottom-up synthetic approach for the semiconductor nanowires also enables several important principles of sustainability in materials and technology development, namely, using earth-abundant elements and using less energy intensive processes. In this talk, I will highlight several recent examples in this lab using semiconductor nanowires and their heterostructures for the purpose of solar-to-electricity and solar-to-chemical energy conversion.
BIOSKETCH
Peidong Yang received a B.S. in chemistry from University of Science and Technology of China in 1993 and a Ph.D. in chemistry from Harvard University in 1997. He did postdoctoral research at University of California, Santa Barbara before joining the faculty in the department of Chemistry at the University of California, Berkeley in 1999. He is currently professor in the Department of Chemistry, Materials Science and Engineering; and a senior faculty scientist at the Lawrence Berkeley National Laboratory. He is the Department Head, North Site Director of the Joint Center for Artificial Photosynthesis (JCAP) at LBNL. He is the deputy director for the Center of Integrated Nanomechanical Systems. Yang is an associate editor for Journal of the American Chemical Society and also serves on editorial advisory board for number of journals including Acct. Chem. Res. and Nano. Lett. He was the founder of the Nanoscience subdivision within American Chemical Society. He has co-founded two startups Nanosys Inc. and Alphabet Energy Inc. He is the recipient of MRS Medal, Baekeland Medal, Alfred P. Sloan research fellowship, the Arnold and Mabel Beckman Young Investigator Award, National Science Foundation Young Investigator Award, MRS Young Investigator Award, Julius Springer Prize for Applied Physics, ACS Pure Chemistry Award, and Alan T. Waterman Award. According to ISI (Thomas Reuters), Yang is ranked as No. 1 in materials science and No. 10 in chemistry for the past 10 years based on average citation per paper. He was recently elected as MRS Fellow. His main research interest is in the area of one dimensional semiconductor nanostructures and their applications in nanophotonics and energy conversion.