ETRI Journal

  • 제36권5호
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  • Pages.847-855
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  • 2014
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  • 1225-6463(pISSN)
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  • 2233-7326(eISSN)
한국전자통신연구원 (Electronics and Telecommunications Research Institute)
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Surface Control of Planarization Layer on Embossed Glass for Light Extraction in OLEDs

  • Cho, Doo-Hee (Components & Materials Research Laboratory, ETRI) ;
  • Shin, Jin-Wook (Components & Materials Research Laboratory, ETRI) ;
  • Moon, Jaehyun (Components & Materials Research Laboratory, ETRI) ;
  • Park, Seung Koo (Components & Materials Research Laboratory, ETRI) ;
  • Joo, Chul Woong (Components & Materials Research Laboratory, ETRI) ;
  • Cho, Nam Sung (Components & Materials Research Laboratory, ETRI) ;
  • Huh, Jin Woo (Components & Materials Research Laboratory, ETRI) ;
  • Han, Jun-Han (Components & Materials Research Laboratory, ETRI) ;
  • Lee, Jonghee (Components & Materials Research Laboratory, ETRI) ;
  • Chu, Hye Yong (Components & Materials Research Laboratory, ETRI) ;
  • Lee, Jeong-Ik (Components & Materials Research Laboratory, ETRI)
  • 투고 : 2013.08.26
  • 심사 : 2014.07.17
  • 발행 : 2014.10.01
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초록

We developed a highly refractive index planarization layer showing a very smooth surface for organic light-emitting diode (OLED) light extraction, and we successfully prepared a highly efficient white OLED device with an embossed nano-structure and highly refractive index planarization layers. White OLEDs act as an internal out-coupling layer. We used a spin-coating method and two types of $TiO_2$ solutions for a planarization of the embossed nano-structure on a glass substrate. The first $TiO_2$ solution was $TiO_2$ sol, which consists of $TiO_2$ colloidal particles in an acidic aqueous solution and several organic additives. The second solution was an organic and inorganic hybrid solution of $TiO_2$. The surface roughness ($R_a$) and refractive index of the $TiO_2$ planarization films on a flat glass were 0.4 nm and 2.0 at 550 nm, respectively. The J-V characteristics of the OLED including the embossed nano-structure and the $TiO_2$ planarization film were almost the same as those of an OLED with a flat glass, and the luminous efficacy of the aforementioned OLED was enhanced by 34% compared to that of an OLED with a flat glass.

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참고문헌

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