6月22日，纳扎尔巴耶夫大学Charles Surya教授访问我中心,并做了题为“Investigation of High Efficiency Perovskite-based Solar Cells”的学术报告，我中心老师和学生积极参与。

Charles Surya教授列举了钙钛矿太阳能电池改善结构、工艺的诸多方法，提出了新的方式，并做出了相对应的改进和优化，在这基础上取得了一系列成果。老师同学为之感叹欣赏，也提出自己的困惑，Charles Surya教授为大家一一解答，反响甚好。

Abstract:

In this talk, I will present an overview of different approaches to accomplish high PCE in PSCs including: i.) improvement of the absorber layer; ii.) enhancement in the device structure; and iii.) incorporation of the light trapping structures. I will first present different growth techniques reported for the growth of high quality MAPI films including: i.) solvent engineering; ii.) vapor assisted process (VASP); and iii.) hybrid chemical vapor depositions (HCVD) technique. Experimental studies conducted in our group demonstrate that significant improvement in the PCE can be achieved by dry O2 treatment of the MAPI layer. Experimental results on photothermal deflection spectroscopy (PDS) show that O2 annealing leads to significant reduction in the localized states in the MAPI layer, which is shown to be the key factor underlying the observed enhancement in the PCE. We will present a detailed discussion on the HCVD growth process that utilizes a N2/O2 carrier gas resulting in significant enhancement in the PCE.

We also report novel work by our group on cryo-controlled growth technique for the deposition of high crystallinity mixed perovskite materials. The technique is shown to result in highly uniform nucleation centers arising from the introduction of a rapid super-saturation condition due to the rapid reduction of the temperature of the precursor layer. This is crucial for the formation of high quality perovskite films. Efficiency has high as 21.4% had been fabricated using this technique.

Biography:

Charles Surya received his PhD in Electrical Engineering from the University of Rochester in USA. His research interest focuses on optoelectronic materials and devices. Professor Surya had published over 200 papers in the field of solid state materials and devices. He joined The Hong Kong Polytechnic University in 1994.  From 2007 to 2010, he served as the Associate Dean of the Faculty of Engineering, and from 2010 to 2012, he served as the Acting Dean of the Faculty of Engineering.  Between 2013 to 2017 he was appointed the Clarea Au Endowed Professor in Energy. Professor Surya joined AOE "Nazarbayev University" in August 2017 as the Dean of the School of Engineering. Dr. Surya served as the Chairman of the IEEE Electron Devices Society, Hong Kong Chapter in 1997 and 2013. From 2014 to 2017 Professor Surya served as the Chair of the Optoelectronic Devices Technical Committee of EDS. He had served as an Editor of IEEE Transactions on Electron Devices and IEEE Journal of Electron Devices Society since 2014.