Fabrication of microcavity light-emitting diodes using highly reflective AlN-GaN and Ta2O5-SiO2 distributed Bragg mirrors

Abstract

We report the fabrication of microcavity light-emitting diodes (MCLEDs) with high reflectivity and crack-free AIN-GaN distributed Bragg reflector (DBR). The 5 lambda microcavity structure consists of an n-type GaN, ten pairs InGaN-GaN multiple quantum wells and p-type GaN sandwiched between the hybrid cavity mode of an AIN-GaN and a Ta2O5-SiO2 DBR. The AIN-GaN DBR has 29 periods with insertion of six AIN-GaN superlattice layers showing a crack-free surface morphology and a high peak reflectivity of 99.4% with a stopband of 21 nm. The output power of MCLED is about 11 mu W at an injection current of 7 mA. The electroluminescence has a polarization property with a degree of polarization of about 51 %.