Research Seminar of Prof. Yan Qingyu from Nanyang Technological University (NTU)

Lecture Time: 10:30 on 13th April, 2018

Lecture Room: C501 of Science and Innovation Building

Lecture Title: Achieving Enhanced Thermoelectric Performance in SnSe2 nanostructures

Qingyu Yan

, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore

Abstract

Thermoelectric (TE) materials, which can convert heat into electricity and generate temperature gradient for cooling purpose, have been extensively studied for clean and reliable energy harvesting systems.I will discuss some of the progress in my group regarding the devleopment of TE materials including PbTe, carbon based ones. In particular, I will discuss on a defect chemistry approach in SnSe2 nanoplate-based pellets, in which the nanoplates show preferable orientation of the (001) planes along the primary surface of the pellet (in-plane). After simultaneous introduction of Se deficiency and Cl doping, the Fermi level of SnSe2 shifts towards the conduction band, resulting in two orders of magnitude increase in carrier concentration and a transition degenerate transport behaviour. In addition, all-scale hierarchical phonon scattering centres, such as point defects, nanograin boundaries, stacking faults and the layered nanostructures cooperate to produce very low lattice thermal conductivity. As a result, an enhanced in-plane ZTmax of 0.63 was achieved for 1.5 at% Cl doped SnSe1.95 pellet at 673 K, which is much higher than the corresponding in-plane ZT of pure SnSe2 (0.08).

Biography

Academic Qualification:

08/2000 - 12/2004 Ph.D., Materials Sci. & Eng., State University of New York at Stony Brook, USA

08/2000 - 12/2004 B.Eng., Materials Sci. & Eng., Nanjing University, China

Professional Qualifications/Memberships:

Member, IEEE Magnetic Society (Nov. 2003 – Nov. 2006)

Member, Materials Research Society (April 2005 – 2008, 2010-now)

Joint Treasurer, Singapore MRS (April 2014- 2016)

Member, Electrochemical Society (January 2017-now)

Chair, Electrochemical Society, Singapore Section, (March 2017 – now)

Summary of Working Experience:

03/2013 - present Associate Professor, Nanyang Technological University, Singapore

02/2008 - 02/2013 Assistant Professor, Nanyang Technological University, Singapore

01/2005 - 10/2007 Postdoc Research Fellow, Rensselaer Polytechnic Institute, USA

08/2000 - 12/2004 Research Assistant, State University of New York at Stony Brook, USA

Awards

1. Tan Chin Tuan Exchange Fellowship in Engineering, 2012
2. Best Poster Award, Next Generation of Batteries Conference, Wollongong, Australia, Aug 2016
3. Best Poster Award, TMS/NY capital district, Albany, NY, USA (2005)
4. Annual Award of International Magnetic Association, 2003