题　目：Doping Semiconductor Quantum Dots

报告人：曾浩

时　间：6月8日（周五）15:30-17:00

地　点：李薰楼468会议室

欢迎参加！

Doping Semiconductor Quantum Dots 

Hao Zeng

Department of Physics, University at Buffalo, the State University of New York

e-mail: haozeng@buffalo.edu

Semiconductor quantum dots are zero-dimensional semiconductor materials where quantum confinement plays an important role in their electronic structure and thus their physical properties. We use solution phase techniques to synthesize colloidal semiconductor quantum dots and their doped nanostructures. In this talk, I will discuss two of our recent work in such systems. First I will discuss diluted magnetic semiconductor quantum dots, where nanoparticles are doped with transition metals. We study carrier-dopant exchange interactions in such systems using circularly polarized magneto-photoluminescence. We found that quantum confinement can profoundly modify such interactions. In the second part of the talk, I will discuss doping strategies for reducing the band gap of TiO₂. TiO₂ is a useful wide gap material for photocatalysis and photovoltaics. However its band gap is too large for effective utilization of solar energy. Doping of TiO₂ has been extensively studied with moderate effects. Here we use co-doping to reduce the band gap by as much as 50%, thus pave the way for their potential commercial applications.

Brief Bio

Hao Zeng received his B.S. degree from Nanjing University and Ph.D. from University of Nebraska. He was a postdoc fellow at IBM T. 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, and was promoted to Associate Professor with tenure in 2009. He is the recipient of an IBM Research Division Award, National Science Foundation CAREER award, UB Exceptional Scholar Award and Li Xun Young Scientist Lecture Series. Dr. Zeng has published more than 70 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 6,000 times, with 14 papers cited for > 100 times. Dr. Zeng’s main research area is condensed matter and materials physics. His present research interests focus on nanoscale magnetism and spintronics, photovoltaic materials and biomagnetics.