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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Built-in Voltage in Organic Light-emitting Diodes depending on the Alg3 Layer Thickness

Alg3 두께 변화에 따른 유기 발광 소자의 내장 전압

  • 이은혜 (홍익대학교 정보디스플레이공학과) ;
  • 윤희명 (홍익대학교 정보디스플레이공학과) ;
  • 김태완 (홍익대학교 정보디스플레이공학과)
  • Published : 2008.03.01
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Abstract

Built-in voltage in ITO/$Alq_3$/ Al organic light-emitting diodes was studied by varying a thickness of $Alq_3$ layer using modulated photocurrent technique at ambient condition. A thickness of the $Alq_3$ layer was varied from 100 to 250 nm. From the bias voltage-dependent photocurrent, built-in voltage of the device was able to be determined. The obtained built-in voltage is about 0.8 V irrespective of the $Alq_3$ layer thickness in the device. This value of built-in voltage confirms that the built-in voltage is generated due to a difference of work function of the anode and cathode. The $Alq_3$ layer thickness independent built-in voltage indicates that the built-in electric field in the device is uniform across the organic layer.

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References

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