Lecture: Fullerene and Nonfullerene-based OPVs 

Lecturer: Prof. Han Young Woo, Korea University 

Time: 4:00pm, Dec 12, 2016

Location: Meeting Room 216 of Energy Building   

Abstract:  

Over the past few decades, polymer solar cells (PSCs) have made a significant progress, showing their potential in low-cost, flexible, lightweight, portable and large-area energy-harvesting devices. Although PC₆₁BM and/or PC₇₁BM structures have been exploited successfully inPSC devices, efforts to modify the fullerene structures for further improving the device performance have been unsuccessful due to theinflexibility in molecular design, difficult purification, poor morphological stability, and limited light absorption in the visible region, etc. In recent years, nonfullerene acceptors have emerged as an alternative candidate of n-type materials to overcome the difficulties of fullerene derivatives in tuning optical and electronic properties. The strong and easily adjustable absorption characteristics of nonfullerene acceptors have been considered a strong point compared to fullerene-type structures. This talk presents a high performance nonfullerene organic solar cell with well-organized donor–acceptor crystalline structures using PPDT2FBT as the donor and small molecular nonfullerene acceptor, NIDCS-HO, as the optimal acceptor. As a result, the optimal device exhibited a maximum efficiency of 7.64% with a V_oc of 1.03 V, a J_sc of 11.88 mA/cm², and a FF of 0.63. This shows that optimal combination of photovoltaic donor and acceptor pairs with complementary absorption, well-aligned frontier energy levels, and well-intermixed crystalline morphology can provide great potential to further increase the power conversion efficiency of nonfullerene solar cells to exceed fullerene-based devices. 

Introduction of Lecturer:   

Dr.  Han Young Woo is the professor of Dept. of Chemistry, College of Science, Korea University. He received his B.S. in Chemistry, Sogang University in 1994, M.S. in Chemistry, Sogang University in 1996, and Ph.D. in Chemistry, Korea Advanced Institute of Science and Technology (KAIST) in 1999. He was Principal Researcher in R&D Center for Chemical Technology, Hyosung Corp from 1999 to 2003, and then moved to University of California at Santa Barbara (UCSB) as Post-doctoral Researcher from 2003 to 2006. He is a Professor in Korea University from 2006. His research interests include synthesis of conjugated polymers for organic electronics and bio-related applications, and water-soluble conjugated molecules (or polymers) and applications in electronic devices, biosensors, TPA fluorophores for biological imaging, etc.

Selected publications (total ~150 SCI papers) 

1.      M. A. Uddin, Y. Kim, R. Younts, W. Lee, B. Gautam, J. Choi, C. Wang, K. Gundogdu*, B. J. Kim*, H. Y. Woo*, “Controlling energy levels and blend morphology for all-polymer solar cells via fluorination of a naphthalene diimide-based copolymer acceptor”, Macromolecules 2016,49 (17), 6374–6383 

2.      O. K. Kwon, M. A. Uddin, J.-H. Park, S. K. Park, T. L. Nguyen, H. Y. Woo*, S. Y. Park*, “A High Efficiency Nonfullerene Organic Solar Cell with Optimized Crystalline Organizations”, Adv. Mater. 2016, 28 (5), 910-916 

3.      J.-E. Jeong, B. Kim, S. Woo, S. Hwang, G. C. Bazan,* H. Y. Woo*, “Principal Factors that Determine the Extension of Detection Range in Molecular Beacon Aptamer/ Conjugated Polyelectrolyte Bioassays”, Chem. Sci. 2015, 6, 1887-1894. 

4.      H. Kang, M. A. Uddin, C. Lee, K.-H. Kim, T. L. Nguyen, W. Lee, Y. Li, C. Wang, H. Y. Woo*, B. J. Kim*, “Determining the Role of Polymer Molecular Weight for High-Performance All-Polymer Solar Cells: Its Effect on Polymer Aggregation and Phase Separation”, J. Am. Chem. Soc. 2015, 137, 2359-2365 

5.      T. L. Nguyen, H. Choi, S.-J. Ko, M. A. Uddin, B. Walker, S. Yum, J.-E. Jeong, M. H. Yun, T. J. Shin, S. Hwang, J. Y. Kim,* and H. Y. Woo*, “Semi-Crystalline Photovoltaic Polymers with Efficiency Exceeding 9% in a ~300 nm Thick Conventional Single-Cell Device”,Energy Environ. Sci. 2014, 7 (9), 3040 – 3051. 

6.    S. Yum, T. An, X. Wang, W. Lee, M. A. Uddin, Y. J. Kim, T. L. Nguyen, S. Xu, S. Hwang, C. Park*, H. Y. Woo* “Benzotriazole-Containing Planar Conjugated Polymers with Non-Covalent Conformational Locks for Thermally Stable and Efficient Polymer Field-Effect Transistors”,Chem. Mater. 2014, 26(6), 2147-2154. 

7.    W. Lee, G.-H. Kim, S.-J. Ko, S. Yum, S. Hwang, S. Cho, Y.-H. Shin, J. Y. Kim*, H. Y. Woo* “Semi-crystalline D-A Copolymers with Different Chain Curvature for Applications in Polymer Opto-electronic Devices”, Macromolecules 2014, 47 (5), 1604–1612. 

8.    Nguyen, B. L.; Jeong, J.-E.; Jung, I. H.; Kim, B.; Le, V. S.; Kim, I.; Kyhm, K.; Woo, H. Y.* “Conjugated polyelectrolyte and aptamer based potassium assay via single- and two-step fluorescence energy transfer with a tunable dynamic detection range”, Adv. Funct. Mater. 2014, 24(12), 1748-1757. 

9.    Lee, B. H.; Jung, I. H.; Woo, H. Y.*; Shim. H.-K.; Kim, G.; Lee, K* “Multi-charged conjugated polyelectrolytes as a versatile work function modifier for organic electronic devices”, Adv. Funct. Mater. 2014, 24, 1100-1108. 

10.    Kim, B.; Jung, I. H.; Kang, M.; Shim, H.-K.*; Woo, H. Y.* “Cationic Conjugated Polyelectrolytes-Triggered Conformational Change of Molecular Beacon Aptamer for Highly Sensitive and Selective Potassium Ion Detection”, J. Am. Chem. Soc. 2012, 134, 3133-3138.