Abstract

Traditional inorganic and organic light emitting diodes (LEDs) suffer poor light extraction efficiency due to total internal reflection (TIR) and waveguiding effects of high-refractive-index materials. Surface grating photonic crystals created by complex and expensive top-down technologies (e.g., electron-beam lithography) have been demonstrated to significantly improve the out-coupling efficiency of LEDs. We have developed an inexpensive and scalable non-lithography technological platform based on colloidal self-assembly for fabricating subwavelength-structured gratings on a large variety of LED-relevant substrates. The resulting wafer-scale subwavelength gratings with tunable optical properties can greatly suppress TIR and waveguiding modes and improve light extraction for both inorganic and organic LEDs.

© 2012 Optical Society of America