Study On The Influence To The Light Efficiency Of AlGaInP-based LED

This paper focuses on the technique of surface roughening、antireflection membrane and changing the shape of electrode to improve extraction efficiency of AlGaInP LED emitting red light.The study of changing the shape of the P-type electrode. The relatively uniform current distribution was obtained by optimizing the shape of the electrode, thereby improve the light efficiency of the chip and improve product quality. The research shows that the voltage of optimized Hollow electrodes (20μm) decrease2%, compared to the existing conventional interdigitated electrode in20mA current, the optical power increased by19%, brightness (mcd) increased by13%.The study of surface roughening. Approved by the experiments:when Useing a wet chemical etch jagged pit whose depth is about2.3μm, the light extraction of device increased most by29%. Almost surface roughening have no effect on the pressure drop of the device. LED emitting red light whitch size of240*240μm surface roughened to improve the light intensity of53%,when the electric current at20mA.The study of Antireflection coating technology combined with surface roughening. In this paper.we growed ITO films and SiOxNy antireflection coating on the roughened surface. Taking into account the complexity of the process and stability, we didn’t make in-depth study in roughened surface+antireflection coating method..