Title :
Light Output Improvement of AlGaInP-Based LEDs With Nano-Mesh ZnO Layers by Nanosphere Lithography
Author :
Chen, Jian-Jhong ; Su, Yan-Kuin ; Lin, Chun-Liang ; Kao, Chien-Chih
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
fDate :
3/15/2010 12:00:00 AM
Abstract :
AlGaInP-based light-emitting diodes (LEDs) with nano-mesh ZnO layers were fabricated by using nanosphere lithography. With 20-mA injection current, the output powers of the nano-mesh ZnO, planar ZnO, and conventional LEDs (LED-I, LED-II, and LED-III, respectively) were approximately 1.66, 1.58, and 1.44 mW, respectively. The improvement of output power in LED-I could be attributed to the nano-mesh ZnO layer that acts as light scattering centers at the surface. In addition, the intermediate refractive index (about n=2) of nano-mesh ZnO layer between those of the p-GaP window layer and air results in the broader critical angle and the reduction of the total internal reflection.
Keywords :
II-VI semiconductors; III-V semiconductors; aluminium compounds; gallium compounds; indium compounds; light emitting diodes; light scattering; nanolithography; nanostructured materials; refractive index; wide band gap semiconductors; zinc compounds; AlGaInP-ZnO; LED; critical angle; current 20 mA; injection current; intermediate refractive index; light output improvement; light scattering centers; light-emitting diodes; nanomesh layers; nanosphere lithography; total internal reflection; window layer; AlGaInP; ZnO; light-emitting diode (LED); nano-mesh; nanosphere lithography;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2009.2039475
