In this seminar, we will focus on our recent work on two different thin film systems – metal halide perovskites and organic semiconductors.For organic semiconductors, through proper control of processing, we are able to realize pinhole free films with single crystal grains with mm dimensions. we have found that organic solar cells incorporating these long-range-ordered films exhibit highly delocalized, and band-like charge transfer (CT) states, contributing to noticeably lower energy losses. We will discuss these aspects and our understanding to-date of which molecules are amenable to the formation of such films.
Hybrid inorganic-organic perovskite materials, most commonly methylammonium lead triiodide (MAPbI3), have captured significant interest in the thin film optoelectronics community due to their impressive optical and electrical properties. For light emitting diodes (LEDs), we are exploring their operation under very high current densities, for high-brightness applications and, hopefully eventually, lasers. Our findings suggest that Joule heating and voltage-induced electrochemical interface reactions present substantial challenges to these operating conditions.
Barry Rand earned a BE in electrical engineering from The Cooper Union in 2001. Then he received MA and PhD degrees in electrical engineering from Princeton University, in 2003 and 2007, respectively. From 2007 to 2013, he was at imec in Leuven, Belgium, ultimately as a principal scientist, researching the understanding, optimization, and manufacturability of thin-film solar cells. Since 2013, he is in the Department of Electrical Engineering and Andlinger Center for Energy and the Environment at Princeton University, currently as an Associate Professor. Prof. Rand’s research interests highlight the border between electrical engineering, materials science, chemistry, and applied physics, covering electronic and optoelectronic thin-films and devices. He has authored over 150 refereed journal publications, has 23 issued US patents, and has received the 3M Nontenured Faculty Award (2014), DuPont Young Professor Award (2015), DARPA Young Faculty Award (2015), and ONR Young Investigator Program Award (2016).
Host: Professor Qiangfei Xia