Speaker: Professor Eugene A. Katz, Ben-Gurion University of the Negev, Sede Boker Campus 84990, Israel

Time: 15:30 pm, October 25, 2018
Venue：Room 512 (West Campus)

Abstract:  Solar cells based on organic?inorganic hybrid perovskites have recently achieved a breakthrough in the field of thin film photovoltaics, with high power conversion efficiencies (PCE) of over 20% for wet-processed devices. Nevertheless, these cells are still far from their full potential and their photovoltaic operation is far from detailed understanding [1].

　　I will discuss the following open questions and challenges:

　　(1) Origin of the high open circuit voltage (Voc) of perovskite solar cells at room temperature;

　　(2) Temperature dependence of principal photovoltaic parameters of the cells;

　　(3) Contradiction between efficient photoluminescence of perovskite materials and low radiative efficiency of the cells;

　　(4) How to improve the radiative efficiency and to achieve the Shockley–Queisser PCE limit?

　　(5) Are the physical instabilities of photovoltaic operation of the cells (hysteresis, ultra-long photoresponse, etc) and their photochemical degradation [2,3] interconnected?

　　(6) How to access operational stability of perovskite cells with reversible degradation [4,5]?

　　References

　　1. W. L. Leong., Z. E. Ooi, D. Sabba, C. Yi, S. M. Zakeeruddin, M. Graetzel, J. M. Gordon, E. A. Katz and N. Mathews. Adv. Mater., 28, 2439 (2016).

　　2. R.K. Misra, S. Aharon, B. Li, D. Mogilyanski, I. Visoly-Fisher, L. Etgar and E.A. Katz. J. Phys. Chem. Lett. 6, 326 (2015).

　　3. R. K. Misra, L. Ciammaruchi, S. Aharon, D. Mogilyanski, I. Visoly-Fisher, L. Etgar and E. A. Katz. Effect of halide composition on the stability of perovskite materials for photovoltaics. ChemSusChem, 9, 2572-2577 (2016).

　　4. M. V. Khenkin, K.M. Anoop, I. Visoly-Fisher, S. Kolusheva, Y. Galagan, F. Di Giacomo, O. Vukovic, B. R. Patild, G. Sherafatipourd, V. Turkovic, H.-G. Rubahnd, M. Madsen, A. Mazanik and E. A. Katz. ACS Appl. Energy Mater., 1, 799 (2018).

　　5. M. V. Khenkin, K. M. Anoop, I. Visoly-Fisher, Y. Galagan, F. Di Giacomo, B. R. Patil, G. Sherafatipour, V. Turkovic, M. Madsen, T. Merckx, G. Uytterhoeven, J. P. A. Bastos, T. Aernouts, F. Brunetti, M. Lira-Cantu and E. A. Katz. Energy Environ. Sci., 11, 739 (2018).

Biography: Prof. Eugene A. Katz received his MSc degree (1982) in Semiconductor Materials Science and Ph. D. (1990) in solid state physics from the Moscow Institute of Steel and Alloys. In 1995, he joined the Ben-Gurion University of the Negev and has been working in the Department for Solar Energy and Environmental Physics ever since (now as a full professor). His research interests include a wide range of photovoltaic materials and devices, such as organic and perovskite-based photovoltaics, concentrator solar cells operated at ultra-high solar concentration (up to 10,000 suns), etc. He has published ~ 120 peer-reviewed papers on these topics.