In the first part of this paper, we present a LED structure adopting double diffused-surfaces on-top transmitted diffuse surface and another diffuse omnidirectional reflector surface on the bottom of LED chip. According to this design, guided light scattered by bottom diffuse omnidirectional reflectors can be again scattered toward to angles inside the escape cone by top diffuse transmittance surfaces. High light external efficiency (∼ 40%) was achieved on this novel structure. This high efficiency could be attributed to the strong scattering efficiency of using double diffuse surfaces, further reducing trapping of light within LED chips. In the second part, we present n-side-up AlGaInP-based LEDs with a triangle-like surface morphology using the adhesive layer bonding technique, followed by wet etching to roughen the surface. The novel AlGaInP LED design could not only reduce internal reflection between rear mirror systems and the semiconductor/air interface, but also to effectively scatter light outside LED devices. copyright The Electrochemical Society.
|Number of pages||13|
|State||Published - 1 Dec 2006|
|Event||State-of-the-Art Program on Compound Semiconductors 45 (SOTAPOCS 45) -and- Wide Bandgap Semiconductor Materials and Devices 7 - 210th Electrochemical Society Meeting - Cancun, Mexico|
Duration: 29 Oct 2006 → 3 Nov 2006