그라비어 인쇄에 의한 전도성고분자 기반의 유기박막트랜지스터 구현
Fabrication of conducting polymer based organic thin film transistors using gravure printing
- 주제(키워드) OTFT , Gravure printing
- 발행기관 고려대학교 대학원
- 지도교수 주병권
- 발행년도 2011
- 학위수여년월 2011. 2
- 학위구분 석사
- 학과 일반대학원 전기전자전파공학과
- 세부전공 전자전기컴퓨터공학 전공
- 원문페이지 75 p
- 실제URI http://www.dcollection.net/handler/korea/000000024720
- 본문언어 한국어
- 제출원본 000045641519
초록/요약
Research and development of electronic devices based on organic materials began some time ago, leading to today’s much more intensive and continuous studies into improving these devices. Of the possible materials developed conducting polymers in particular have several advantages, such as having easy synthesis properties, high electrical conductivities, and good stabilities in various environments. In addition, the easily soluble characteristic of polymer is favorable in view of the manufacturing process. Spin casting is a typical conventional technique based on a solution process, however, much material is wasted and it is an unsuitable method for large area applications. Conventional methods using photolithography, vacuum processes can be easily replaced by printing methods which consume less material than that for spin casting. Among the numerous methods, the gravure printing method can be cost efficient by implementing high throughput R2R printing techniques and the substrate size is not limited in this method. Furthermore, this method has changed the production processes within the electronics industry by turning a discontinuous step process from patterning to deposition into continuous R2R printing process with plastic substrates. In this work, we fabricated polymer TFTs using a gravure printer. Generally, organic solutions are difficult to print by gravure printer due to their solution properties, such as viscosity, stability, adhesion, the creation of bad film, etc. In order to overcome these problems, we used a vapor polymerization method along with the gravure printing method. PVA (Poly(vinylalcohol), used as a matrix polymer, has excellent film forming, emulsifying and adhesive properties. Consequently, the printing was well done. After the printing of the oxidant dispersed PVA dissolved in DI water, processing the vapor of the pyrrole monomer polymerization finally formed a polymer thin film. The PPy TFT shows the p-type operates in depletion mode with no property of the building of an inversion layer at high positive gate voltage. In this study, the conductivity of the film was dependent on the concentration of the oxidant and the polymerization time. However, a conductivity of PPy film is very high. Thus, the conductivity needs to be lower for transistor applications. So we fabricated TFTs by controlling the various conditions. The drain current decreased with an increase of the PVA and decreased with the decrease of the FTS concentration. As lower the conductivity of this device, it is seen more clearly current variation depending on the gate voltage. The performance of device was advanced by adjusting condition mentioned above. Furthermore, PPy (Poly(pyrrole) is known for its sensitivity to moisture, therefore it has been investigated for use in humidity sensors. The PPy transistor showed that it well responds to moisture and also show an recovery tendency although it was not fully well done.
more목차
Abstract ........................................................................................................... i
목차 ............................................ iv
그림목차 .................................................. vi
표목차 …………………………………………………………………………………… viii
1장 서론.......................................................................................................... 1
2장 이론적 고찰.............................................................................................. 4
2.1 유기박막 트랜지스터 개요 4
2.2 유기박막 트랜지스터를 위한 재료 8
2.3 전도성 고분자 14
2.4 그라비어 프린팅 18
3장 실험………………………………………………………………………………… 25
3.1 소자제작 25
3.1.1 기판준비 26
3.1.2 인쇄용 용액제조 26
3.1.3 그라비어 인쇄 및 후 공정 27
3.2 측정 29
4장 결과 및 고찰.............................................................................................. 30
4.1 기상중합에 의한 박막의 형성과정 30
4.2 인쇄 된 박막의 특성 분석 33
4.3 제작된 트랜지스터 소자의 전기적 특성분석 43
4.4 산화제 농도에 따른 제작된 소자의 전기적 특성 개선 45
4.5 매트릭스 폴리머 농도에 따른 제작된 소자의 전기적 특성 개선 48
4.6 제작된 소자의 수분에 대한 감지반응 시험 51
5장 결론............................................................................................................ 54
참고문헌………………………………………………………………………………… 56
감사의 글........................................................................................................ 63
