报告人：Shu Kong So教授
香港浸会大学物理系，先进材料研究所
邀请人：郝晓涛 教授
报告时间：2017年5月9日下午15:30
报告地点：知新楼C座702量子报告厅
摘要：Most optimized, high performance, bulk-heterojunction polymer solar cells have an active layer thickness of about 100nm. The thin active layer is unfavorable for optical absorption and film coating. This talk looks into a ternary approach to address this problem. We discuss how to make thick BHJ cells that retain 90% PCEs of the optimized thin-film cells. The BHJs under investigations are PTB7:PC71BM, PTB7-Th:PC71BM and P3HT:PCBM. Into these BHJs, a ternary component, p-DTS(fbtth2)2 is introduced. Without p-DTS(fbtth2)2, the binary thick-film devices (~200nm, ~200nm and ~400nm) have PCEs of 6.3%, 7.4% and 3.2%. With p-DTS(fbtth2)2, the corresponding BHJs have markedly improved PCEs of 7.6%, 8.3% and 3.9%, respectively. The results are more than 90% the PCEs of the optimized binary BHJs. The origins of the improvement are investigated. Addition of the ternary component p-DTS(fbtth2)2 enhances hole mobility and reduces trap states. Both observations are well correlated with improved FFs of the ternary BHJ cells. Photothermal deflection spectroscopy and 1H nuclear magnetic resonance are used to trace the electronic and the nano-scale interactions of the p-DTS(fbtth2)2 with the polymer and fullerene. The results suggest the p-DTS(fbtth2)2 behaves as conducting bridges in between two neighboring polymer segments.
报告人简介：Shu K So obtained his bachelor degree from Hamilton College and PhD in Physics from Cornell University. In Cornell, he did research on surface physics and chemistry of small molecules on metal and semiconductor surfaces. He was a postdoctoral fellow in the Chemistry Department of the University of Toronto where he used scanning tunneling microscope to study surface photochemistry. In 1992, he joined the Department of Physics, Hong Kong Baptist University. Now he is a Professor of Physics. In addition, he is the Associate Head of the Department, and the Program Director for the BSc (Hons) Program in Physics and Green Energy. His major research interest is in the physics and the chemistry of thin film materials including transport and defect study of organic/perovskite films, fabrication of organic solar cells and thin film transistors, surface and optical spectroscopies of materials.
