报告题目：Perovskite Solar Cells
报告人：Prof. Qiquan Qiao (乔启全), Harold C Hohback Professor and Graduate Coordinator, Department of Electrical Engineering and Computer Science, South Dakota State University, USA
Dr. Qiquan Qiao is Harold C Hohback professor and graduate coordinator in Electrical Engineering at South Dakota State University (SDSU). Current research focuses on polymer photovoltaics, dye-sensitized solar cells, Perovskite solar cells and lithium ion batteries. He has published more than 120 peer reviewed papers in leading journals including Energy and Environmental Science, Journal of the American Chemical Society, Advanced Materials, Advanced Functional Materials, Advanced Energy Materials, Nanoscale, and Nano Energy, etc. He has received 2014 F O Butler Award for Excellence in Research at SDSU, 2010 US NSF CAREER, and 2009 Bergmann Memorial Award from the US-Israel Bi-national Science Foundation.
Perovskite solar cells have become a highly efficient solution processable device because of its broad band light absorbing property and long charge diffusion length. For the first time, room temperature heating free growth and crystallization of perovskite films in ambient air without use of thermal annealing was reported. Highly efficient perovskite nanorod-based solar cells were made using ITO/PEDOT:PSS/CH3NH3PbI3 nanorods/PC60BM/Rhodamine/Ag. All the layers except PEDOT:PSS were processed at room temperature thereby eliminating the need for thermal treatment. Perovskite films were spin coated inside a N2 filled glove box and immediately were taken outside in air having 40% relative humidity (RH). Exposure to humid air was observed to promote the crystallization process in perovskite films even at room temperature. Perovskite films kept for 5 hours in ambient air showed nanorod-like morphology having high crystallinity, with devices exhibiting highest PCE of 16.83%, which is much higher than the PCE of 11.94% for traditional thermal-annealed perovskite film based devices. It was concluded that moisture plays an important role in room temperature crystallization of pure perovskite nanorods, showing improved optical and charge transport properties, which resulted in high performance solar cells