报告题目：Understanding the importance of bulk-heterojunction microstructure stability in solution-processed organic solar cells
报告人：李宁
报告时间：2018年01月05日（星期五） 下午14:00
报告地点：907号楼1445室
报告人简介
李宁，男，1986年5月出生，同济大学材料科学与工程专业本科,德国埃尔朗根纽伦堡大学（FAU）材料科学与工程专业硕士/博士，现在德国FAU Brabec教授团队从事研究工作，任课题组长及科研项目负责人。长期从事新型可印刷有机光电功能材料及器件的表征与研究，重点研究新一代光电功能器件的新型结构以及产业化进展。近五年在国际权威期刊共发表学术论文50余篇，他引2200余次，其中Science 1 篇，Nat. Energy 1篇，Nat. Commun. 2篇，Energy & Environ. Sci. 10篇，Adv. Energy Mater. 14篇，有4篇入选ESI高被引论文。主持德国研究基金会-中国国家自然科学基金委中德国际合作项目1项，FAU-亥姆霍兹联合会埃尔朗根纽伦堡研究所联合研究项目2项，获2013年国家优秀自费留学生奖学金，2015年FAU优秀博士毕业生奖，2017年IUMRS-ICAM国际会议青年科学家奖铜奖，2017年FAU新兴人才计划资助
报告摘要
The performance of organic solar cells (OSCs) is governed by the delicate, optimized bulk-heterojunction (BHJ) microstructure, where organic donor and acceptor are fine-mixed in the nanometer regime to facilitate exciton dissociation. For the same material composition, the quantum efficiencies may vary from close to 100 % to even less than 10 % as a function of processing. To push organic photovoltaics towards commercial applications, a module efficiency of >10% in combination with an operational lifetime of >10 years is required. Therefore, the morphology evolution as well as the stability of BHJ microstructure has to be well investigated and analyzed.
In this presentation, I will examine the reliability and stability of BHJ microstructures for various solution-processed OSCs and explore their potential for large-scale mass production. We recently found that selected high performance systems gain their high excellent performance from a meta-stable microstructure, which quickly relaxed to the thermodynamic equilibrium state under external stress, such as light or thermal stress. The so called burn-in degradation is identified as a spinodal de-mixing due to the low miscibility of donor and acceptor, which is turned out to be a major challenge for the development of stable and efficient OSCs. Even though the BHJ microstructure can be kinetically tuned for achieving high-performance, the inherently low miscibility of donor and acceptor leads to spontaneous phase separation even in the solid state.
（报告联系人：周祎老师）