Properties of silicon power rectifiers

THE STATIC electrical properties of small-area silicon P-N junction rectifiers prepared by the alloy fusion process have been described by Pearson and Sawyer1 in 1952. Since that time rectifiers of the same type and having about the same P-N junction area (in the order of 0.0005 to 0.001 square centimeter (cm)) have become commercially available. The development of these rectifiers confirms theoretical expectations as to the superior electrical properties of silicon over germanium for semiconductor devices. These superior properties, which include extremely low reverse currents, high rectification ratios, and the ability to operate successfully at high ambient temperatures, are attributed to the wider energy gap in silicon (1.15 electron volts) as compared to germanium (0.75 electron volt).