SEMINAR
　　The State Key Lab of
　　High Performance Ceramics and Superfine Microstructure
　　Shanghai Institute of Ceramics, Chinese Academy of Sciences

　　中 国 科 学 院 上 海 硅 酸 盐 研 究 所 高 性 能 陶 瓷 和 超 微 结 构 国 家 重 点 实 验 室 

　　Nanostructured Cu2Se-based Materials for Energy Conversion

　　Pierre F. P. Poudeu

　　University of Michigan, USA

　　Thermoelectric Materials Design Through High-Throughput Computations

　　朱 虹

　　上海交通大学

　　时间：2016年5月26日（星期四）下午2: 00

　　地点： 2号楼600会议室（国家重点实验室）

　　欢迎广大科研人员和研究生参与讨论！

　　联系人：陈立东（4804）、史 迅（2803）

　　报告摘要：

　　Nanostructured Cu2Se-based Materials for Energy Conversion

　　Widespread application of photovoltaic and thermoelectric technologies requires the development of low-cost high efficiency materials such as transition metal chalcogenides (TMC). For example, Cu2Se (CS) and its off stoichiometric counterparts display thermoelectric figure of merit, ZT, of up to 1.8 at 1000K. Also, CuInSe2 (CIS) is among the leading high efficiency solar absorber materials for photovoltaic devices. The technological importance of these two materials, along with their close structural relationship motivated the synthesis of a series of (1-x)CS - (x)CIS nanocomposites in order to explore the effect of coherently embedded CIS nanoinclusions on the electronic and thermal transport properties of Cu2Se. Electronic transport data show that the incorporation of a small fraction of In (x = 3% to 5%) increases the electrical conductivity of the composites compared to that of pristine Cu2Se. However, samples with large indium content showed diffraction peaks corresponding to the CIS phases on XRD patterns. This indicates a limited solubility of indium in Cu2Se and precipitation of CuInSe2 as secondary phase. At low CIS, the CS matrix dominates electronic transport, whereas CIS matrix dominates electronic transport in composites with high CIS content (≥50%). While the introduction of nanophases reduces the overall thermal conductivity (k) for 3%, 5%, and 10% CIS concentrations by disrupting phonon transport, an increase in k is observed for composites with higher CIS concentrations. Remarkably, the CS/CIS composite with 3 mol% CIS shows a maximum ZT of 1.55 at 800K, which correspond to 29% improvement in ZT compared to the value of 1.2 reported for Cu2Se at 800K.

　　Thermoelectric Materials Design Through High-Throughput Computations

　　Materials genome initiative to accelerate materials innovations through the integration of experiment, computation and data is becoming a global action. Within recent years, high-throughput computations have been applied to screen tens of thousands of materials to find better materials for batteries, solar cells, catalysts, and hydrogen storage. In this talk, I will focus on its application to thermoelectrics and discuss how a combined effort of computations and experiments leads to the discovery of a new family of thermoelectric materials with a measured zT of 0.8. At the end, I will briefly comment on the challenges and limitations with such an effort.

　　报告人简介：

　　Ferdinand Poudeu is currently an Associate Professor of Materials Science and Engineering at the University of Michigan and a Guest Professor at Wuhan University of Technology (China). He earned a Ph.D in Inorganic Solid State Chemistry (2004) from the Technical University of Dresden in Germany. He was a research associate at Northwestern University (2006 – 2007) and Michigan State University (2004 – 2006), and served as Assistant Professor of Chemistry and Materials Science at the University of New Orleans (2007 – 2011) where he was named Early Research Professor (2010-2011) in recognition of his “outstanding and innovative work”. He joined the Materials Science and Engineering at the University of Michigan as Assistant Professor in 2011, where he established the Laboratory for Emerging Energy and Electronic Materials (LE3M). His research portfolio currently includes (1) bulk nanostructured thermoelectric materials; (2) novel low-dimensional spintronic materials; (3) multifunctional quantum metamaterials; and (4) intercalation compounds for lithium rechargeable batteries. Dr. Poudeu has graduated 3 PhDs, mentored over 30 undergraduate students; 6 high school students; 2 high school teachers, 5 postdoctoral research associates, and published over 70 journal articles and conference proceedings. He is an Associate Editor for “Reviews in Advanced Sciences and Engineering” and “Journal of Nanoscience Letters” and contributes on the editorial boards of three other Journals.