Ecole Polytechnique Federale de Lausanne, Switzerland
By Prof. Mohammad Khaja Nazeeruddin, Ecole Polytechnique Federale de Lausanne, Switzerland.
Organic halide salt passivation is considered to be an essential strategy to reduce defects in state-of-the-art perovskite solar cells (PSCs). This strategy, however, suffers from the inevitable formation of in-plane favored two-dimensional (2D) perovskite layers with impaired charge transport, especially under thermal conditions, impeding photovoltaic performance and device scale-up. To overcome this limitation, we studied the energy barrier of 2D perovskite formation from ortho-, meta- and para-isomers of (phenylene)di(ethylammonium) iodide (PDEAI2) that were designed for tailored defect passivation. Treatment with the most sterically hindered ortho-isomer not only prevents the formation of surficial 2D perovskite film, even at elevated temperatures, but also maximizes the passivation effect on both shallow- and deep-level defects. The ensuing PSCs achieve an efficiency of 23.9% with long-term operational stability (over 1000 hours). Importantly, a record efficiency of 21.4% for the perovskite module with an active area of 26 cm2 was achieved.
Co-authors:
Cheng Liu1, Yi Yang1, Kasparas Rakstys2 , Bin Ding1, Vytautas Getautis2, Yong Ding1, Mohammad Khaja Nazeeruddin*1
(1) Institute of Chemical Sciences and Engineering, EPFL VALAIS, Sion, 1951, Switzerland.
(2) Department of Organic Chemistry, Kaunas University of Technology, Radvilenu pl. 19, Kaunas, 50254, Lithuania.
Biography
Prof. Nazeeruddin current research at EPFL focuses on Perovskite Solar Cells and Light-emitting diodes. He has published more than 618 peer-reviewed papers, ten book chapters, and inventor/co-inventor of over 75 patents, which are well cited 87’047 with an h-index of 135 having an average citation of over 141. Google Scholar h-index is 152, and total citations are 112’012. His group has developed layer-by-layer growth of 3-dimensional and 2-dimensional perovskites yielding solar to the power conversion efficiency of 22.5% certified at Newport calibration PV lab earlier this year. His group has earned worldwide recognition and leadership in perovskite solar cells as evidenced by Times of higher Education selection as “the top 10 researchers in the world working on the high impact perovskite materials and devices”. This recognition is based on the accumulated results and impacts generated between 2014 and 2018.
He is elected to the European Academy of Sciences (EURASC), and Fellow of The Royal Society of Chemistry. According to ISI listing, he is one of the most cited chemists in 2014, 2015, 2016, 2017 and 2018, and one of the 20 scientists identified by Thomson Reuters as The World Most Influential Scientific Minds 2015, 2017, and 2018 from all scientific domains.