主讲人： 曾浩

时  间： 05.19 上午8:30

地  点： 教三楼321

主  办： 物理系

Abstract

Dye-sensitized solar cells (DSSCs) are photoelectrochemical cells using photosensitized wide band gap nanoporous oxide semiconductors sensitized by dye molecules. DSSCs convert light energy to electrical energy through photo-excitation, charge separation in photosensitive dye molecules anchored to the surface of TiO2 nanoparticles, electron injection and charge transport in the TiO2 nanoparticle network. DSSCs attracted great attention due to their respectable efficiency with very low fabrication cost, good performance under diffuse light conditions, semi-transparency and multi color range possibilities, and the ability to be fabricated on flexible substrates. Its main efficiency limiting factor is the random hopping of electrons within the TiO2 nanoparticle network, which causes carrier trapping and recombination. The charge transport and collection can be enhanced by employing ordered nanostructures such as nanowire or nanotube arrays. However, DSSCs based on nanowire or nanotube arrays with high power conversion efficiency have yet to be demonstrated. In this talk, I will focus on DSSCs using highly crystalline free-standing TiO2 nanotube (FSTNT) arrays to enhance charge transport and collection, and hence, power conversion efficiency. DSSCs based on FSTNT arrays revealed high power conversion efficiency of >10% and short-circuit photocurrent density comparable to that of monocrystalline silicon solar cell.

Bio

Hao Zeng received his B.S. degree from Nanjing University and Ph.D. from University of Nebraska, both in physics. He was a postdoc fellow at IBM Thomas J Watson Research Center between 2001 and 2004. He joined the Physics Department at the University at Buffalo, the State University of New York as an Assistant Professor in 2004. In September 2009 he was promoted to tenured Associate Professor. He is the recipient of an IBM Research Division Award, National Science Foundation CAREER award and UB Exceptional Scholar Award. Dr. Zeng has published more than 60 papers in Journals including Nature, Nature Nanotechnology, Nano Letters, Journal of the American Chemical Society and Advanced Materials. These papers have been cited for more than 4,000 times, with 10 papers cited more than 100 times. Dr. Zeng’s main research area is condensed matter and materials physics. His present research interests focus on nanoscale magnetism and spintronics, materials for energy applications and biomagnetics.