A Holographic Method for Increasing External Light Output Efficiency of Organic Light-Emitting Diodes

• Main Authors: Han-Tsung Hsueh, 薛翰聰
• Other Authors: Hua-Kuang Liu
• Format: Others
• Language: en_US
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/20616013557726849371

碩士 === 國立臺灣大學 === 光電工程學研究所 === 92 === In this thesis, we have proposed a new method of using phase holograms to increase the external light coupling efficiency of the organic light-emitting diodes (OLEDs). We have reviewed the physical structures, operating principles, light emission models and methods of increasing the external light coupling efficiency of an OLED and proposed the improvement of the efficiency by the use of phase holograms. We have proposed three experimental approaches based on the holographic phase modification of the front, back, or both sides of the substrate of the OLED. The phase holograms are expected to be able to guide the emission straight out from the OLED device and hence the external light coupling efficiency can be improved. After we demonstrate the simplified holographic experiment, the diffraction efficiency of the hologram versus angular variation and spectrum dispersion of the incident light has been discussed. Finally, we have discussed the challenges in experiments and suggested future work for this important topic that is useful for display and illumination applications.