[멀티스케일 에너지 강좌]Strategies for high-efficiency organic photovoltaic cells

교육과학기술부 글로벌프론티어 (재)멀티스케일 에너지 시스템 연구단은 나노기술과 에너지 기술의 융합을 통하여 혁신적 미래 광에너지와 분자에너지 원천기술 개발을 목표로 하는 멀티 스케일 에너지 시스템 연구사업을 추진하고 있습니다. 연구단에서는 격주로 멀티스케일 에너지 강좌를 개최합니다. 관심 있는 분들의 많은 참석 바랍니다.
1. 제 목 : Strategies for high-efficiency organic photovoltaic cells: optics and fabrication issues
2. 연 사 : 김창순 교수 (서울대 나노융합학과)
3. 일 시 : 2012년 7월 16일 (월) 16:00 ~ 17:00
4. 장 소 : 서울대학교 신공학관 (301동) 117호 세미나실
5. 내 용 : Abstract : Despite continuing effort focused on organic photovoltaic (PV) cells, the highest power-conversion efficiency (PCE) reported so far is below 10%, much smaller than that of thin-film solar cells based on inorganic semiconductors. We describe limitations to PCE of organic PV cells, focusing on optics- and fabrication-related issues, and present our recent work that can overcome these limitations.
(1) Short diffusion lengths of excitons in organic semiconductors require that the device thickness must be < ~100 nm, resulting in insufficient absorption of solar photons. We perform systematic analyses on optical properties of organic PV cells, where a metallic 2-dimensional crossed grating is used as the electrode facing solar illumination, and present general guidelines for optimizing such devices.
(2) In terms of fabrication, due to weak van der Waals interactions between organic molecules or polymers, post-deposition patterning of organic semiconductors must avoid the exposure to solvents or high temperatures. This makes very difficult the fabrication of PV cells in tandem geometries, a device architecture with a great potential to high PCEs. We fabricate polymer tandemPV cells by transferring the photoactive layer of the top cell onto the bottom cell by stamping, and demonstrate that the stamping process leads to a high fill factor of 56 % and a open-circuit voltage (Voc) that is the sum of the subcell Voc''s.
6. 약 력 :
- M.A. & Ph.D. in Electrical Engineering, Princeton University, USA (1998 2005)
- Post-doctoral Research Associate, Dept. of Electrical and Computer Engineering, Duke University, USA (2005 2008)
- Research Scientist, Dept. of Electrical and Computer Engineering, Duke University, USA (2008 2009)
- Assistant Professor, Dept. of Nano Science and Technology, Seoul National University (2009 present)
* 문의 : 멀티스케일 에너지 시스템 연구단 연구지원본부(889-6669,6670) 남기태 교수 (재료공학부), 최만수 교수 (기계항공공학부)