Thin film AlGaInP light emitting diodes with different reflectors

The reflectivity versus incident angle of a GaP/Au reflector,a GaP/SiO_2/Au triple ODR(omni-directional reflector) and a GaP/ITO/Au triple ODR was calculated.Compared to AlGaInP LEDs with a GaAs absorbing substrate, thin film LEDs with a Au reflector,a SiO_2 ODR and an ITO ODR were fabricated.At a current of 20 mA,the optical output power of four samples was respectively 1.04,1.14,2.53 and 2.15 mW.The Au diffusion in the annealing process reduces the reflectivity of the Au/GaP reflector to 9%.The differe...     

Effect of substrate orientation on Zn-doping of AIGalnP grown by atmospheric pressure orgamometallic vapor phase epitaxy

Dependence of hole concentration ofp(Zn) — (Al_0.6Ga_0.4In_0.5P on substrate orientation was examined. It increases with tilting the substrate from (100) towards (511)A. Addition of ann-GaAs cap layer on top of the quaternary increases hole concentration while ap-GaAs cap shows little effect.     

Growth of AIGalnP in a high-speed rotating disk OMVPE reactor

In an OMVPE reactor with a high speed rotating disk, growth of a quaternary material AIGalnP is carried out after a basic investigation on the GaAs growth rate uniformity. Experimental growth rate and growth efficiency results are compared with the theoretical results obtained from an infinite diameter rotating disk model. Distributions of the lattice mismatch, PL spectra and carrier concentration were measured to clarify the disk rotation effect on these properties. The main reason for non-uniformities is not the disk rotation but the temperature distribution on a substrate carrier.