| 报告题目 | Engineering of active layer nanomorphology for improved charge transport in polymer solar cells |
| 报告人 | Prof. QIAO Qiquan |
| 报告人单位 | Center for Advanced Photovoltaics, South Dakota State University, USA |
| 报告时间 | 2014-07-15 |
| 报告地点 | 中国科学技术大学环境资源楼报告厅 |
| 主办单位 | 合肥微尺度物质科学国家实验室、中国科学院能量转换材料重点实验室、中国科学技术大学化学与材料科学学院 |
| 报告介绍 | 报告摘要：
Organic solar cells have the potential to spawn a new generation of light-weight, low-cost, and solar-powered products on thin and flexible substrates. Current energy conversion efficiency of 10.6% has been in reach. In this talk, I will discuss the engineering of active layer nanomorphology for improved charge transport in polymer solar cells via various acceptor loadings and solvent additives. Effects of PCBM weight ratios on the optical and electrical characteristics of bulk heterojunction 2,1,3-Benzothiadiazole based polymer namely PBT-T1:PCBM film were investigated and correlated with changes to nanomorphology. Increasing PCBM loading in active layer blends led to more amorphous polymer chains with smaller domain sizes. Addition of small amounts of additive DIO in parent solvent for the 1:2 mixing ratio led to enhanced photovoltaic performance due to reduction in series resistance, larger shunt resistant and higher charge carrier mobility caused by improved crystallinity of the polymer. Photo-CELIV measurements with varying delay time showed that 1:2 cells exhibited higher density of extracted charge carriers and was further enhanced when processed from DCB+DIO solvent mixture. Power conversion efficiency for single junction devices at 1:2 blending weight ratio with additive and PC70BM reached up to 5.65% with a high open circuit voltage of 0.9V. In addition, charge transport and bimolecular recombination dynamics were correlated with nanomorphology by studying the role of domain purity and domain size on charge transport and recombination kinetics in inverted bulk heterojunction solar cells. Domain purity was found to play an important role in short circuit current density while the fill factor is mainly dependent upon domain sizes.
报告人简介：
Dr. Qiquan Qiao is an associate professor in Electrical Engineering at South Dakota State University (SDSU). Current research focuses on polymer photovoltaic, dye-sensitized solar cell and lithium ion battery materials and devices. Dr Qiao has published more than 50 peer reviewed papers in leading journals including Journal of the American Chemical Society, Advanced Functional Materials, Energy and Environmental Science, Nanoscale, etc. In addition to his recent receipt of the 2014 F O Butler Award for Excellence in Research at SDSU, he also received 2012 3M Faculty Award and College of Engineering Young Investigator Award. In 2010, Dr. Qiao was granted an Early Career Award from the US National Science Foundation, and in 2009 he received the Bergmann Memorial Award from the US-Israel Bi-national Science Foundation. During his graduate study, Dr. Qiao received the 2006 American Society of Mechanical Engineers Solar Energy Division Graduate Student Research Award and the 2006 Chinese Government Award for Outstanding Students Abroad. |
