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Efficient Organic Light-emitting Diodes with Aluminum-doped Zinc Oxide Anodes

알루미늄 도핑된 산화아연 양극을 적용한 고효율 유기발광다이오드

  • 이호년 (순천향대학교 전자정보공학과) ;
  • 이영구 (삼성종합기술원 디스플레이 디바이스&프로세싱 랩) ;
  • 정종국 (한국산업기술대학교 신소재공학과) ;
  • 이성의 (한국산업기술대학교 신소재공학과) ;
  • 오태식 (선문대학교 전자공학부)
  • Published : 2007.08.01

Abstract

Properties of organic light-emitting diodes (OLEDs) with aluminum-doped zinc oxide (ZnO:Al) anodes showed different behaviors from OLEDs with indium tin oxide (ITO) anodes according to driving conditions. OLEDs with ITO anodes gave higher current density and luminance in lower voltage region and better EL and power efficiency under lower current density conditions, However, OLEDs with ZnO:Al anodes gave higher current density and luminance in higher voltage region over about 8V and better EL and power efficiency under higher current density over $200mA/cm^2$. These seemed to be due to the differences in conduction properties of semiconducting ZnO:Al and metallic ITO. OLEDs with ZnO:Al anodes showed nearly saturated efficiency under high current driving conditions compared with those of OLEDs with ITO anodes. This meant better charge balance in OLEDs with ZnO:Al anodes. These properties of OLEDs with ZnO:Al anodes are useful in making bright display devices with efficiency.

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