Over the past 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 heterojunctions between the perovskite with the p and n-type charge extraction layers. 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 multi-junction solar cells, with a feasibility of much higher efficiency than current commercial flat plate PV technologies.
In this seminar, Professor Henry Snaith will present the brief recent history of the emergence of perovskite photovoltaics, and highlight the key factors which are important for reaching the maximum efficiencies. he will 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. He 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 and all perovskite monolithic 2-terminal tandem cells. Professor Snaith will also look at some new prospects for novel perovskite-like semiconductors beyond lead-halides, and present expanding activity in perovskites for light emitting applications.
ABOUT THE SPEAKER
Professor Snaith undertook his PhD at the University of Cambridge, working on organic photovolatics under Professor Sir Richard Friend, then spent two years at the EPFL, in Switzerland, as a post doc working on dye-sensitised solar cells under Professor 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. He has raised over £12 million in research funding from the UK research councils, European Commission and Industry over the past eight years, which supports his research team. In December 2010 he founded Oxford Photovoltaics Ltd, which is rapidly commercialising the perovskite solar technology transferred from his university laboratory. Oxford PV Ltd has thus far raised £28 million in equity funding and is in the process of establishing a manufacturing facility for the perovskite solar cell technology transferred from Professor Snaith’s university laboratory.
Professor Snaith has received several 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). At the age of 37 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 second most influential scientific mind in 2016, based on citations of his seminal scientific papers on perovskite solar cells.