Professor of Chemical Engineering

Research Areas

Organic Materials for Photonics and Electronics

Research Interests

ELECTRICALLY CONDUCTING FIBERS FOR SMART TEXTRONICS
Wearable devices can be applied for military goods, human health and convenience including bio-monitoring systems , communications tools, augmented reality and smart military uniforms. Flexible and strong fiber with high electrical conductivity is an essential element for flexible or wearable electronic and electrical devices since conducting fiber can be used to form electrical current path even on cloth, shoes and other wearable electronics. It can be also used as electromagnetic shielding material and surface heating element. Moreover, it can be applied to electrical devices such as yarn supercapacitor, transistor, battery and home interior materials. For this reason, many researches have been carried out on various kinds of electrically conducting fibers. It is, however, still challenging to achieve fibers with both high conductivity and general fiber properties. In our research group, metallically conducting fibers with superior mechanical properties have been fabricated by using novel spinning processes.

POLYMERIC MATERIALS FOR OLED ENCAPSULATION
Polymer thin film can be used as flexible buffer layer for transparent and flexible moisture barrier coating for OLED encapsulation technology. Moisture barrier coating for OLED consists of alternate stacking of inorganic or metal oxide layer and organic polymer layers. Metal oxide layer formed by atomic layer deposition (ALD) process prevents water permeation, while organic polymer layer mainly provides mechanical flexibility. Polymer layer may also extend the moisture diffusion path to improve moisture barrier property of the barrier coating. Therefore, fabrication of transparent, flexible polymer thin film without any crack is very important for buffer layer of flexible OLED encapsulation. In our research group, fabrication of copolymer thin films has been studied by using the initiated chemical vapor deposition (iCVD) for OLED encapsulation. We have also developed flexible moisture-absorbent/adhesive materials for edge sealing of OLED since moisture can penetrate OLED through the edge of the device.

Selected Publications

1. S. Paek, J. Lee, H. S. Lim, J. Lim, J.Y. Lee and C. Lee,”The influence of electron-deficient comonomer on chain alignment and OTFT characteristics of polythiophenes”, Synthetic Metals, 160, 2270 (2010).

2. J.A.Lim, S. H. park, J.H. Baek, Y.D.Ko, H.S. Lee, K. Cho, J.Y. Lee, D. R. Lee, D.R. Lee and J.H.Cho,”Selectively patterned highly conductive poly
(3,4-ethylenedioxythiophene)-tosylate electrodes for high performance
organic field-effect transistors”, Applied Physics Letters, 95, 233509 (2009).

3. S. H.Cho, J.Joo, B. R.Jung, T.M Ha and J. Y. Lee, “PET fabric/poly
(3,4-ethylenedioxythiophene) composite as polymer electrode in redox
supercapacitor”, Macromolecular Research, 17,746 (2009).

4. H.D.N.,J.M.Ko,H.J.Kim,S.K.Kim,S.H.Cho,J.D.Nam and J.Y.Lee,
“Electrochemical properties of poly(3,4-ethylenedioxythiophene) nanofiber non-Woven web formed by electrospinning”, J. of Nanoscience and Nanotechnology, 8,4718 (2008)

Professional Experience

한국과학기술원 연구원(1985-1987)
한국과학기술연구원 선임연구원(1992-1998)
성균관대학교 공과대학 부학장(2008-2009)
한국섬유공학회 총무이사(2008-2009), 한국고분자학회 전무이사(2010)