The role of reflective p-contacts in the enhancement of light extraction in nanotextured vertical InGaN light-emitting diodes.
We report effective methods for improving light extraction efficiency for n-side-up vertical InGaN light-emitting diodes (LEDs). For the LEDs with high reflectance Ag-based p-contacts, nanotexturing of the n-GaN surface using a combination of photonic crystals and photochemical etching drastically enhances the efficiency of extraction from the top surface. In contrast, the LEDs with low reflectance Au-based p-contacts show significantly less improvement through the nanotexturing. These experimental results indicate the critical role of high reflectance p-contacts as well as surface texturing in improving the light extraction efficiency of the vertical LEDs for solid-state lighting.
Jang
Ho Won
HW
Division of Advanced Materials Science, Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, Korea.
Ryu
Seong Wook
SW
Yu
Hak Ki
HK
Lee
Sanghan
S
Lee
Jong-Lam
JL
D003460:Crystallization / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D008029:Lighting / Q000295:instrumentation*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008839:Microelectrodes; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D010316:Particle Size; D012666:Semiconductors; D013499:Surface Properties
D046911:Macromolecular Substances; D007204:Indium; C473348:gallium nitride; D005708:Gallium; C513701:indium nitride