Blue-Emitting Diodes of 6H-SiC Prepared by Chemical Vapor Deposition

Silicon carbide (SiC) blue-light-emitting diodes with an external quantum efficiency of 2×10-5 photons/electron were prepared by the chemical vapor deposition method. Epitaxial growth of 6H-SiC has been carried out at 1800°C on a 6H-SiC substrate using the SiCl4-C3H8-H2 system. Epitaxial layers of the n and p types with appropriate carrier concentrations were obtained by doping N from NH3 and Al from AlCl3, respectively. A pn junction was prepared in one growth run by a double epitaxial process. The peak wavelength of the electroluminescence spectrum was 495 nm.