Printed Plastic Transparent Electrode Developed with Enhanced Electrical Conductivity

- Professor Lee Kwanghee at Materials Science & Engineering, Dr. Lee Sungho and researcher, Kim Nara and Ki Seyoung on Ph.D program 

- Plastic thin film with high efficiency electrical conductivity manufactured using sulfuric acid …Posted as front cover article on Advanced Materials

 

 

 

 

□The printed plastic transparent electrode with high electrical conductivity enough to overcome limitation of existing transparent electrode* has been developed by a research team in Korea. Manufacturing of conductive plastic thin film for transparent electrode with a simple solution processing with sulfuric acid is expected to contribute to advancing commercialization of flexible electric devices.

* Transparent electrode: An electrode that has both high light transmission (higher than 85%) in visible ray range and high electrical conductivity (higher than 1000S/cm) used as core component for various display devices and solar cell. 

O Led by professor Lee Kwanghee at Materials Science & Engineering and Dr. Lee Sungho (a corresponding author) at Research Institute for Solar and Sustainable Energies at GIST and conducted by Kim Nara and ki Seyoung (co-first author), researchers on Ph.D course at Materials Science & Engineering with the sponsor of the medium-standing researchers support project (Leap Forward Research) and the leading research center support project promoted by the Ministry of Science, ICT and Future Planning and National Research Foundation and the research result was posted as a front cover article of the April 9^th edition of Advanced Materials, a top international journal in the materials science.
* Paper Title: Highly Conductive PEDOT:PSS Nanofibrils Induced by Solution-Processed Crystallization

□Conductive plastic with high light transmission and electrical conductivity is gaining attention as materials for transparent electrode replacing ITO* that is easy to break and uses Indium, a rare and highly expensive materials.

* ITO (Indium Tin Oxide) : Solution of indium oxide mixed with tin oxide with high level of light transmission and electrical conductivity, that is widely used for transparent electrode of various display and solar cell.

O However, conductive plastic has limitation in commercialization as it requires additional process to ensure evaporation in vacuum to get electrical conductivity that is equivalent to ITO.

□The research team has found that processing the conductive plastic materials with sulfuric acid can improve electrical conductivity up to the level of ITO.

O Conductive plastic is light, flexible and easy to fabricate as it can be produced just as being printed and expected to be widely used for flexible display, touch screen and organic solar cell.

□Sulfuric acid increases electrical conductivity as it enhances crystallinity by truing conductive plastic* from grain-based into nanofibrils-based form. With this, the complicated vacuum evaporation processing to increase electrical conductivity can be skipped.  

O In research experiments, when organic solar cell is produced using the plastic thin film as transparent electrode, it shows 95% of photoelectric conversion efficiency** compared to ITO-based electrode.

* PEDOT : PSS : Conductive plastic with high transmission in visible ray range and research for application is active as it is widely used as materials for transparent electrode.

** Photoelectric conversion efficiency: Efficiency rate of solar light being converted into solar energy in solar cell.

□Professor Lee said “The research findings proved that the solution process can strengthen electrical conductivity of plastic and are expected to advance commercialization of transparent and flexible printed electrode that can replace ITO that is more prone to break down.”