关于举行埃尔朗根-纽伦堡大学李宁博士学术报告的通知

2019-03-20 115

报告题目：Development of Organic Solar Cells with Excellent Performance and Stability

报告人：李宁博士 Institute of Materials for Electronics and Energy Technology (i-MEET), Friedrich-Alexander University Erlangen-Nürnberg, Martensstr. 7, 91058 Erlangen, Germany.

邀请人：叶轩立教授

报告时间：2019年3月25日（周一）下午4:00

报告地点：北区科技园1号楼发光材料与器件国重502会议室

报告摘要

Owing to the rapid development over the last few years, the power conversion efficiency (PCE) of solution-processed organic solar cells (OSCs) has surpassed the 15% milestone, exhibiting great potential for future energy supply.¹ The performance of OSCs is governed by the delicate, optimized bulk-heterojunction (BHJ) microstructure, where organic donor and acceptor are fine-mixed in the nm 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. Therefore, the morphology evolution as well as the stability of BHJ microstructure has to be well investigated and analysed.

In this contribution, the stability of BHJ microstructures for various model OSCs will be examined.^2-5 We recently found that selected high performance OSCs 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 OSCs.² To overcome this microstructural instability, we introduce a top-down approach to rationally screen molecular phase stabilizers from a database with more than 10000 small molecules.⁴ According to the simple but elegant selection criteria, 21 small molecules are finally identified as promising candidates based on their interaction parameters with organic donor and acceptor. By adding a small amount of molecular stabilizer, the intrinsic instability of metastable OSCs, for instance PCE11:PCBM, can be successfully overcome without compromising device performance. We further investigate the industrial viability of state-of-the-art OSCs based on several representative NFAs.^3,5 The most stable OSCs exhibit a PCE of ∼8% with an extrapolated T₈₀ lifetime >11,000 hours, which would lead to a very impressive operational lifetime approaching 10 years.⁵

¹N. Li et al., Nature Energy 2017, 2, 772.
²N. Li et al., Nature Commun. 2017, 8, 14541.
³N. Li et al., Energy Environ. Sci. 2018, 11, 1355.
⁴C. Zhang et al., Energy Environ. Sci. 2019, 12, 1078.
⁵X. Du et al., Joule 2019, 3, 215.

个人简介

李宁博士，2014年毕业于德国埃尔朗根-纽伦堡大学（FAU）材料科学与工程专业，师从有机光电领域专家Christoph Brabec教授。现继续在Brabec教授团队从事科学研究工作，任光伏器件课题组组长，HI-ERN访问科学家，郑州大学兼职PI。长期从事新型可印刷光电功能材料及器件的表征与机理研究，重点探索新一代光电功能器件的新型结构以及产业化进展。近年来在国际专业学术期刊发表论文70余篇，包括Science，Nature Energy，Nature Commun.，Energy Environ. Sci.等（其中IF > 20的35篇）。主持DFG-NSFC中德国际合作项目1项，FAU-HIERN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，2018年德国青年科学家奖提名。