Title :
Enhancement of Light Extraction Efficiency of Gallium Nitride Flip-Chip Light-Emitting Diode With Silicon Oxide Hemispherical Microlens on its Back
Author :
Lee, Ming-Kwei ; Ho, Chen-Lin ; Fan, Cho-Han
Author_Institution :
Dept. of Electr. Eng., Nat. Sun Yat-sen Univ., Kaohsiung
Abstract :
Silicon oxide (SiO2) hemispherical microlens with the density of 8.2 times 108 cm-2 has been formed on a sapphire substrate of gallium nitride (GaN) light-emitting diode (LED) by liquid phase deposition to enhance the light extraction efficiency. For flip-chip LED, the SiO2 microlens exhibits 1.25 times enhancement of optical output power. In comparison of the conventional LED, there is 61% enhancement for flip-chip LED with a SiO2 microlens.
Keywords :
III-V semiconductors; flip-chip devices; gallium compounds; light emitting diodes; liquid phase deposition; microlenses; silicon compounds; wide band gap semiconductors; Al2O3; GaN; SiO2; gallium nitride flip-chip light-emitting diode; light extraction efficiency; liquid phase deposition; optical output power; sapphire substrate; silicon oxide hemispherical microlens; Gallium nitride; III-V semiconductor materials; Lenses; Light emitting diodes; Microoptics; Ohmic contacts; Optical films; Refractive index; Resists; Silicon; $hbox{SiO}_{2}$ microlens; GaN flip-chip light-emitting diode (LED); light extraction efficiency;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2008.926892
