blue LEDs

Large-gap semiconductors are potentially useful materials for the manufacture of light-emitting diodes. Their spectral range now includes the blue and ultra-violet regions. In addition, some of the materials can be used to manufacture high-power microwave devices and sensors for high-temperature operation. During the past three years, the physical properties of SiC (silicon carbide) have been the subject of an enlightening study. This article describes this semiconductor material and shows how blue-emitting SiC diodes can be produced by methods similar to those for existing GaAs (gallium arsenide) or GaP (gallium phosphide) devices.