Keynote Speech:

Metal Halide Perovskite Solar Cells

Prof. Henry Snaith Professor, Department of Physics, University of Oxford, UK

Date: 13 Dec 2016 (Tue)
Time: 9:30 - 10:15am
Venue: TY Wong Hall, 5/F, Ho Sin Hang Engineering Building, CUHK

Abstract:

Over the last few years metal halide perovskites have risen to become a very promising PV material, captivating the research community. In the most efficient devices, which now exceed 22% solar to electrical power conversion efficiency, the perovskite is present as a solid absorber layer sandwiched between n and p-type charge collection contacts. Increasing importance of improving solar cell operation is reliant upon understanding and controlling thin-film crystallisation and controlling the nature of the p and n-type contacts. In addition, understanding and enhancing long term stability of the materials and devices if a key driver. Despite the competitive efficiency, and assuming that stability challenges will be surmountable, for perovskites to feasibly enter the PV market, the commercial modules need to deliver something which other technologies cannot: Their unique selling point is ease of tuning the band gap, which can deliver both hybrid and all-perovskite multifunction solar cells, with a feasibility of much higher efficiency than current commercial flat plate PV technologies. Here I will present our work on developing thin film perovskite solar cells, and specifically highlight recent advances in understanding the thin film crystallisation and enhancing the long term operational stability through compositional design of the perovskite, in addition to appropriate choice and adaptation of charge selective contacts. I will demonstrate efficient perovskite solar cells with band gaps ranging from 1.2 to 1.8 eV and show these materials integrated into hybrid tandem solar cells with silicon, in addition to all perovskite monolithic 2-terminal tandem cells. Finally I will discuss the further challenges to overcome before this technology is ready for production.

About speaker:

Henry Snaith undertook his PhD at the University of Cambridge, working on organic photovolatics under Prof Sir. Richard Friend, then spent two years at the EPFL, in Switzerland, as a post doc working on dye-sensitized solar cells under Prof Michael Grätzel. He returned to the Cambridge to take up a Fellowship for Clare College in 2006, and moved to the Clarendon Laboratory of Oxford Physics in 2007, where he now holds a professorship and directs a group researching in optoelectronics, specifically organic, hybrid and perovskite devices. His research is focused on developing new materials and structures for hybrid solar cells and understanding and controlling the physical processes occurring at interfaces. He has made a number of significant advances for emerging PV, including the first demonstration of “gyroid” structured titania for dye solar cells, the first demonstration of a mesoporous single crystal of TiO2, and the recent discovery that metal halide perovskites can operate extremely efficiently in thin film based solar cells. His recent work with perovskite solar cells has transformed the PV research community, and arguably created a new field of research. In December 2010 he founded Oxford Photovoltaics Ltd. which is rapidly commercializing the perovskite solar technology. Oxford PV Ltd. is in the process of establishing a manufacturing facility for the perovskite solar cell technology transferred from Prof Snaith’s university laboratory. Prof Snaith has received a number of research awards including the Institute of Physics Patterson Medal and Prize (2012), the Materials Research Society Outstanding Young Investigator Award (2014) and the European Materials Research Society EU-40 Materials Prize (2015). He was elected as a Fellow of the Royal Society in 2015, which reflects the global recognition he has garnered for his outstanding work. In addition he was named one of “Natures Ten” people who mattered in 2013, and assessed as being the world’s 2nd most influential scientific mind in 2016, based on citations of his seminal scientific papers on perovskite solar cells.