Journal of the Optical Society of Korea

Optical Society of Korea (한국광학회)
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Fabrication of Viewing Angle Direction Brightness-Enhancement Optical Films using Surface Textured Silicon Wafers

  • Jang, Wongun (3D Convergence R&D Center, Korea Photonics Technology Institute) ;
  • Shim, Hamong (3D Convergence R&D Center, Korea Photonics Technology Institute) ;
  • Lee, Dong-Kil (3D Convergence R&D Center, Korea Photonics Technology Institute) ;
  • Park, Youngsik (3D Convergence R&D Center, Korea Photonics Technology Institute) ;
  • Shin, Seong-Seon (Department of Photonic Engineering, Chosun University) ;
  • Park, Jong-Rak (Department of Photonic Engineering, Chosun University) ;
  • Lee, Ki Ho (Research Center of i-components Inc.) ;
  • Kim, Insun (FORIS Co. Ltd.)
  • Received : 2014.07.04
  • Accepted : 2014.09.26
  • Published : 2014.10.25
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Abstract

We demonstrate a low-cost, superbly efficient way of etching for the nano-, and micro-sized pyramid patterns on (100)-oriented Si wafer surfaces for use as a patterned master. We show a way of producing functional optical films for the viewing angle direction brightness-enhancement of Lambertian LED (light emitting diode)/OLED (organic light emitting diode) planar lighting applications. An optimally formulated KOH (Potassium hydroxide) wet etching process enabled random-positioned, and random size-distributed (within a certain size range) pyramid patterns to be developed over the entire (100) silicon wafer substrates up to 8" and a simple replication process of master patterns onto the PC (poly-carbonate) and PMMA (poly-methyl methacrylate) films were performed. Haze ratio values were measured for several film samples exhibiting excellent values over 90% suitable for LED/OLED lighting purposes. Brightness was also improved by 13~14% toward the viewing angle direction. Computational simulations using LightTools$^{TM}$ were also carried out and turned out to be in strong agreement with experimental data. Finally, we could check the feasibility of fabricating low-cost, large area, high performance optical films for commercialization.

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References

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