Journal of the Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회논문지)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Work Function Increase of ITO Modified by Self Assembled Monolayer for Organic Electrical Devices

유기 디스플레이 소자를 위한 Self Assembled Monolayer의 표면개질을 이용한 ITO의 일함수 증가

  • 지승현 (건국대학교 신기술융합학과) ;
  • 김수호 (건국대학교 신기술융합학과) ;
  • 고재환 (건국대학교 신기술융합학과) ;
  • 윤영수 (건국대학교 신기술융합학과)
  • Published : 2006.06.01
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Abstract

Indium tin oxide (ITO) used as an electrode in organic light emitting diodes (OLEDs) and organic thin film transistors (OTFTs) was modified by a self-assembled monolayer (SAM). For device fabrication, surface of the ITO was modified by immersion in a solution including various phosphonic acid at room temperature in order to increase work function of an electrode. The work function of ITO with SAM was measured by Kelvin probe. Work function increase of 0.88 eV was observed in ITO with various SAM. Therefore, ohmic contact is achieved in an interface between ITO and organic semiconductors (pentacene). We analyzed the origin of work function increase of ITO with SAM by X-ray photoelectron spectroscopy. We confirmed that increase of oxygen bonding energy attributed to increase the work function of ITO. These results suggested that ITO with the SAM gives a high possibility for high performance of OLEDS and OTFTs.

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References

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