新加坡南洋理工大学物理与数学学院熊启华教授讲座 :Laser Cooling of Semiconductors （半导体激光制冷）
时间：12月23日 10点
地点：集贤宾馆第四会议室
个人简介：Qihua Xiong received his B. S. degree in physics from Wuhan University in 1997, and then finished three years graduates studies at Shanghai Institute of Applied Physics, Chinese Academy of Sciences. He went to the United States in 2000 and received a Ph. D. degree under the supervision of Prof. Peter C. Eklund from the Pennsylvania State University in 2006. After three years postdoctoral experience in Prof. Charles M. Lieber’s group at Harvard University, he joined Nanyang Technological University as an assistant professor in 2009. He is a Fellow of Singapore National Research Foundation awarded in 2009. Prof. Xiong’s research focuses electrical and optical properties of semiconductor nanomaterials. He recently ventured into the field of 2D layered materials and laser cooling of semiconductors.
摘要：Optical irradiation accompanied by spontaneous anti-Stokes emission can lead to cooling of matter, in a phenomenon known as laser cooling, or optical refrigeration proposed by Pringsheim in 1929. In solid-state materials, laser cooling is achieved by the annihilation of phonons. It would be interesting to realize laser cooling in semiconductors. Here we report a net cooling by about 40 kelvin in a semiconductor using group-II-VI cadmium sulphide nanoribbons, or nanobelts, starting from 290 kelvin. Our findings suggest that, alternatively, group-II-VI semiconductors with strong exciton-LOP coupling could be harnessed to achieve laser cooling and open the way to optical refrigeration based on semiconductors.
