(Lecture) Extreme work functions to minimize charge injection/extraction resistance to organic semiconductor devices
date:2019-11-19 pageviews:24

Speaker:Professor Peter HO 

Time: 16:00, Nov. 19th, 2019

Venue: Room 502, Building of State Key Laboratory of Luminescent Materials and Devices, Wushan Campus

Abstract: In this talk, following the recent availability of doped polymer charge-injection layers with systematically tunable work functions at constant carrier density, I’ll review our recent understanding of work function, which is determined not only by electronic structure, but also Coulomb effects, both e‒ion interaction (Madelung potential) and e‒e interaction (Hubbard splitting),[1] different from conventional semiconductors; and the consequences for ohmic injection, which is characterized by an ohmic transition,[2] beyond Fermi-level pinning, that is key to maximizing fill factor and minimize contact resistance for organic solar cells. I’ll also discuss some recent results beyond the ohmic transition.

[1] Png, Ang, Teo, Choo, Tang, Belaineh, Chua, Ho, Nature Commun. (2016) 7:11948 doi:10.1038/ncomms11948

[2] Tan, Png, Zhao, Ho, Nature Commun. (2018) 9:3269 doi:10.1038/s41467-018-05200-w

Biography:Peter Ho was born in Singapore. He received B.Sc. in Materials Science from National University of Singapore, 1996, and Ph.D. in Physics from University of Cambridge in 2001 under the supervision of Professor Richard Friend. He was appointed Junior Research Fellow of St John’s College, Cambridge, during which he also worked at Bells Labs, Murray Hill, as visiting scientist for two years. He was appointed Assistant Professor of the Department of Materials Science, NUS in 2005, and promoted to full professor at the Department of Physics in 2016. He was appointed Vice Dean of the Faculty of Science in 2014, and Deputy Dean since 2018. He sits on the management board of several university-level research institutes. His research interests span a variety of topics in polymer organic semiconductors with strong industry orientation, focusing chiefly on establishing new capabilities and understanding. Peter has published over 80 articles in international journals, and been named inventor on over 20 patent families. He is cited 10,000+ times (h-index, 45), and has co-authored 20+ papers that have been cited more than 100 times each. He was named Top Outstanding Young Person (Academic Leadership) by the Junior Chamber of Commerce, Singapore in 2009.