Plenary Speakers

Abstract

Green energy technologies have been highly demanded for a sustainable development. In this talk, our recent studies for the electricity conversion/storage using nano carbon and polymeric materials will be presented. These will include the material design, synthesis, and device fabrication, targeting for high energy efficiency and understanding the mechanism using simpler or cheap materials.

References:

[1] “Super-elasticity of three-dimensionally cross-linked graphene materials all the way to deep cryogenic temperaturas”,
Kai Zhao1,2,*, Tengfei Zhang1,2,*, Huicong Chang1,2, Yang Yang1,2, Peishuang Xiao1,2, Hongtao Zhang1,2, Chenxi
Li1,2, Chandra Sekhar Tiwary3, Pulickel M. Ajayan3,† and Yongsheng Chen1,2,† Science Advances, 2019, 5(4),
eaav2589.

[2] "A Tandem Organic Solar Cell with PCE of 14.52% Employing Subcells with the Same Polymer Donor and Two
Absorption Complementary Acceptors", Lingxian Meng, Yuan-Qiu-Qiang Yi, Xiangjian Wan,* Yamin Zhang, Xin Ke, Bin
Kan, Yanbo Wang, Ruoxi Xia, Hin-Lap Yip, Chenxi Li, and Yongsheng Chen* , Adv. Mater, 2019, 1804723.

[3] "Organic and solution-processed tandem solar cells with 17.3% efficiency", Lingxian Meng, Yamin Zhang, Xiangjian
Wan*, Chenxi Li, Xin Zhang, Yanbo Wang, Xin Ke, Zuo Xiao, Liming Ding*, Ruoxi Xia, Hin-Lap Yip, Yong Cao, Yongsheng
Chen*, Science, 2018, 361, 1094-1098.

[4] "Monolithic 3D Cross-linked Polymeric Graphene Materials and the Likes: Preparation and Their Redox Catalytic
Applications", Yanhong Lu, Yanfeng Ma, Tengfei Zhang, Yang Yang, Lei Wei, and Yongsheng Chen , J. Am. Chem. Soc.,
2018, 140 (37), pp 11538–11550.

[5] “Macroscale light propulsion of 3D cross-linked graphene”, Tengfei Zhang†, Huicong Chang†, Yingpeng Wu†,
Peishuang Xiao, Ningbo Yi, Yanhong Lu, Yanfeng Ma, Yi Huang, Kai Zhao, Xiaoqing Yan, Zhibo Liu, Jianguo Tian and
Yongsheng Chen*, Nature Photon., 2015, 9, 471-476.

Biography

Education

Working Experience

Honors, Awards and Memberships

• Highly cited scientist by Thomson Reuters for last ten years (2018, 2017, 2016, 2015, 2014)
• China Nature Science Award, 2rd class, 2018
• “Thousand Talent Program” of China, 2011
• “Thousand Talent Program” of Tianjin, 2010
• First Class Award of Nature Science of Tianjin City, 2010
• Adjunction Professor, University of Texas at Dallas, 2010-present, UT Dallas
• Von Rudloff Award, University of Victoria, 1996, 1995
• University of Victoria Fellowship, University of Victoria, 1993-1997

Publication more than 300 papers in journals including over 50 papers in Science, Nature, Nature Photo, Nature Comm, JACS, Adv. Mat., Acc. Res. Chem., Nano Lett

Total Citing more than 45,000 times, H-index: 94 (2019.05, Google scholar)

2018, 2017, 2016, 2015, 2014 listed as one of the world highly cited scientists of last ten years by Thomas Reuter

Abstract

Polymer solar cells (PSCs) are a promising alternative for clean and renewable energy due to their potential to be fabricated onto large area, light-weight flexible substrates by solution processing at low cost. Our recent progress in the molecular design of p-type conjugated polymers containing multi-fused ladder-type structure and the n-type fullerene derivatives containing cross-linkable styryl or epoxy groups will be presented. Both ladder-type conjugated polymers and n-type fullerene derivatives are used to fabricate high efficient bulk heterojunction PSCs and organic thin film transistors (OTFTs). The cross-linkable fullerene derivatives are also used to fix the morphology of bulk heterojunction (BHJ) layer so as to improve the stability of PSCs. Furthermore, several series of non-fullerene acceptors (NFAs) containing heptacyclic dithienocyclopentacarbazole (DTC)-based cores were synthesized and blended with J71, PBDB-T and PBDBTF of which featuring complementary absorption and well-matched energy levels. Side-chain engineering strategy was used to design the first two NFAs, DTC(4Ph)-IC and DTC(4R)-IC which contain four alkylphenyl side chains and four alkyl side chains on the DTC unit, respectively. Fluorination approach was used to design the other two NFAs, DTC(4Ph)-4FIC and DTC(4R)-4FIC which contain four fluorine atoms on the IC units. The non-fullerne acceptors were blended PBDB-TF to fabricate PSCs with a PCE value higher than 15 %.

References:

[1] Y. J. Cheng, S. H. Yang, C. S. Hsu, Chem Rev. 109, 5868 (2009).

[2] C. H. Hsieh, Y. J. Cheng, P. J. Li, C. H. Chen, M. Dubosc, R. M. Liang and C. S. Hsu, J. Am. Chem. Soc. 132, 4887 (2010).

[3] Y. J. Cheng, C. H. Hsieh, Y. He, C. S. Hsu and Y. F. Li. J. Am. Chem. Soc. 132, 17381 (2010).

[4] J. S. Wu, S. W. Cheng, Y. J. Cheng and C. S. Hsu, Chem. Soc. Rev., 44, 1113 (2015).

[5] J.-S. Wu, Y.-J. Cheng, T.-Y. Lin, C.-Y. Chang, P.-I. Shih, C.-S. Hsu, Advanced Functional Materials. 22, 1711 (2012).

[6] Y.-Y. Lai, Y.-J. Cheng, C.-S. Hsu, Energy & Environmental Science. 7, 1866 (2014).

[7] C. H. Li, C. C. Chang, Y. H. Hsiao, S. H. Peng, Y. J. Su, S. Heo, K. Tajima, M. C. Tsai, C. Y. Lin, C. S. Hsu, ACS Appl Mater
Interfaces. 11, 1,1156 (2019).

[8] T.-W. Chen, Y.-T. Hsiao, Y.-W. Lin, C.-C. Chang, W.-T. Chuang, Y. Li, C.-S. Hsu, Mater. Chem. Front. 3, 829 (2019).

Biography

Prof. Chain-Shu Hsu has received his Ph.D. degree from Department of Macromolecular Science Case Western Reserve University in 1987.  He joined Department of Applied Chemistry, National Chiao Tung University (NCTU) in 1988 as an associated professor.  He was promoted to full professor in 1991.  He has served as Department-Chair and Dean of R&D at NCTU.  He also served as Vice President of NCTU.  Currently, he is the Chair Professor of NCTU. 

Prof. Chain-Shu Hsu is a well-respected scientist in the field of liquid crystalline and conjugated polymers. He did a lot of pioneering research in molecular design and synthesis of liquid crystalline and conjugated polymers.  He also works on both materials for opto-electronic applications, in particular, in the area of flat panel display, light emitting diodes, and organic photovoltaics. For example, he developed the blade coating technique for large area polymer light-emitting diode devices. He also pioneered the concept of introducing liquid crystalline group to conjugated polymers, which are important for generating polymer light-emitting diodes with polarized emission. In addition, he designed many multifused-type conjugated polymers that can be used for fabricating polymer solar cells with high efficiencies. By incorporating a cross-linked fullerene interlayer, his group was able to fabricate an inverted solar cell device with high power conversion efficiency.  He has published more than 300 SCI papers and 35 patents.  He has also given more than 100 invited, keynote or plenary lectures in various scientific conferences.  Prof. Hsu has received a number of prestigious awards and prizes for his academic achievements which include Excellent Research Awards from the Ministry of Science and Technology, France-Taiwan Scientific Prize, TECO Award, Ho-Chin Tui Award, Academic Award from Ministry of Education, Nanotechnology Award, SPSJ International Award, Y. Z. Hsu Scientific Chair Professorship, and the SID SlottowOwaki Award. 

Professor Hsu is very active in Taiwan and international academic society.  He has served as President of Taiwan OLED and PLED Society, Taiwan Liquid Crystal Society, Polymer Society of Taipei, Chemical Society Located in Taipei, and Pacific Polymer Federation.  He has also served as advisory board of Polymer, Macromolecules, ACS Macro Letters, and Journal of Polymer Science Polymer Chemistry.

Abstract

In the design of organic electronics materials, bis-lactam units have long been exploited as an efficient electron acceptor moiety with appropriate frontier molecular orbital energies. While the typical bis-lactam structures like diketopyrrolopyrrole (DPP) and isoindigo(IID) units had successfully been utilized for the high performance organic semiconductors, we came to notice that they render somewhat limited molecular planarity and oscillator strength when connected to the lateral conjugated units like thiophene. In this context, we have designed and synthesized a series of high performance organic molecules and polymers containg a novel fused bis-lactam structure of 1,5-naphthyridine2,6-dione laterally flanked by two thiphene units (NTDT).[1,2] Based on the single crystal structure and photophysical properties, NTDT was shown to have outstanding molecular planarity, tight stacking, and high oscillator strength. Indeed, the D-A polymers containing NTDT as the acceptor unit were synthesized to show 9.63% PCE. [2,3] It was also shown that NTDT is an excellent  organic semiconductor with a transistor hole mobility of 1.29 cm²V-¹s-¹. [4]

References:

[1] T. M. Swager et al., Synfacts 2017, 13, 0153; https://doi.org/10.1055/s-0036-1589928
[2] W. Yoon et al., Macromolecules 2016, 49, 8489-8497; https://doi.org/10.1021/acs.macromol.6b01680
[3] W. Yoon et al., Adv. Energy. Mat. 2017, 8, 1701467, https://doi.org/10.1002/aenm.201701467
[4] J. H. Kim et al., ACS Applied Materials & Interfaces, 2019, 11, 8301−8309; https://doi.org/10.1021/acsami.8b20168

Biography

Soo Young Park earned his PhD degree from Seoul National University in 1988. He has been a senior researcher in the Korea Institute of Science and Technology (KIST, Korea) in 1985-1995. He joined Seoul National University as a faculty member in 1995 and was promoted and tenured to the full professor of Materials Science and Engineering in 2004. He has been a director of the Organic Nanophotonics National Research Laboratory (NRL) of Korea in 2004-2009 and a director of the Creative Research Initiative Center for Supramolcular Optoelectronics Materials (CSOM) in 2009-2018. He has been awarded with Shinyang Engineering Award (2005), Samsung Polymer Award (2007), Academic Research Award of Seoul National University (2009), and Sudang Prize (2016). In 2010, he was appointed as the fellow of Korean Academy of Science and Technology (KAST). His research areas include design and synthesis of molecular electronics and photonics materials related to the fluorescence, phosphorescence, electroluminescence, solar cell, transistor, battery, artificial photosynthesis, photochromism, sensing, optical recording, and nonlinear optics. Web of Science Researcher ID of Soo Young Park is G-1080-2012 and relevant Publons page is as follows. https:// publons.com/researcher/2719016/soo-young-park/publications/

Abstract

The surface photoalignment of liquid crystal (LC) materials has extensively been achieved on solid surfaces, which now constitutes an important area in LC display fabrication industry. We have recently developed a new strategy to control the alignment of LCs from the free (air) surface side.1 A photoresponsive skin layer at the free surface is prepared on LC polymer films by surface segregation or inkjet printing of an azobenzene (Az)-containing photoresponsive LC polymer. The non-photoresponsive mesogens up to 10 mm thickness can be achieved by a photoresponsive skin layer of 20 nm thickness existing at the free surface. Inkjet drawing followed by irradiation with linearly polarized visible light provided a clear patterned birefringent image ascribed to a homeotropic-homogeneous alignment patterning.¹

Reversible control of the mesogen orientation between the homeotropic and planar modes were also possible by alternative irradiation with UV and visible light in suitable temperature conditions.² The mesogen alignment changes could be repeated at least several times. This reversible photoalignment process can be compared with the original command layer system on the solid surface initiated by Ichimura et al. in 1988.³

In this presentation, some other recent attempts will also be provided on the polymer processing procedures based on the free surface stragegy such as formation of high density polymer brush via surface segregation and self-assembly4 and photoinitiated Marangoni flow that takes place at inkjet printed areas on LC polymer surfaces. The latter can be proposed as a new microfabrication procedure (Figure 1).⁵

Figure 1. Photoinduced Marangoni flow

Acknowledgment: These projects have been performed with great efforts on azobenzene side chain LC polymer film of research associates and students shown in the references. processed at inkjet-printed regions.5

References:
[1] K. Fukuhara, S. Nagano, M. Hara, and T. Seki, Nat. Commun. 2014, 5, 3320 (2014); T. Seki, Polym. J. (review) 2014, 16,
751: S. Nagano, Lagnmuir (Future Article), 2019, ASAP.
[2] T. Nakai, D. Tanaka, M. Hara, S. Nagano, T. Seki, Langmur 2016, 32, 909.
[3] K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, K. Aoki, Langmuir 1988, 4, 1214.
[4] K. Mukai, M. Hara, S. Nagano, Angew. Chem. Int. Ed. 2016, 55, 14028.
[5] I. Kitamura,K. Oishi, M. Hara, S. Nagano, T. Seki, Sci. Rep. 2019, 9, 2556

Biography

Education

1979  Graduated from Tokyo Institute of Technology (Polymer Chemistry)

1986  Dr. of Engineering (Polymer Chemistry) from Tokyo Institute of Technology

Carrier

Activities of Academic Society

Expertise

Photofunctional Polymers, Ultrathin Polymer Films, Molecular Assemblies, Liquid Crystals

Cuerrent Topics

Photoalignment of liquid crystallie polymer materials, Mass migrations in photoresponsive polymer films

Awards