Fabrication And Theoretical Analysis Of Gan-based Vertical Light-emitting Diodes With Sio_2 Current Blocking Layer

摘要

We report the fabrication and characteristics of 1 x 1 mm~2 blue vertical light-emitting diodes (VLEDs) with a SiO_2 current blocking layer (CBL), together with their theoretical analysis in terms of electrical, optical and thermal properties. The SiO_2 CBL improves the total light extraction efficiency by relieving the current crowding under the metal n-electrode. Additionally, the total light extraction efficiency of LEDs with SiO_2 CBL remains almost the same independent of injection current, whereas that of conventional VLEDs is gradually decreased with injection current. The optical output power (Pout) for the VLED with SiO_2 CBL is increased by about 10% at 350 mA in a wafer level without serious degradation in operating voltage resulting from the insertion of SiO_2 CBL, thus resulting in a high P_(oul) of 670 mW at 950 mA. The simulated light-current-voltage characteristics of the fabricated devices were reasonably consistent with the measured results.