关键词: 发光二极管, 场效应管, 禁带宽度, 固体继电器, 光电效应

Abstract: Solid state relays are increasingly used in the military and civilian markets, replacing traditional electromagnetic relays in large quantities. The isolation of solid state relays has changed from transformer isolation to optical isolation. Optical isolation solid state relays have become the mainstream design of many manufacturers. Optical isolated solid state relays are used in large numbers, but when using light emitting devices such as infrared light emitting diodes, if the wavelength of infrared light emitting diodes selected does not match the bandgap width of semiconductor devices such as field effect transistors, improper handling will result in the output leakage currents of the solid state relays being exceeded. The influence of infrared light emitting diodes on the output leakage current of solid state relays is analyzed through photoelectric effect, the mechanism of this influence is verified through experimental tests, and an improvement method is proposed.

Key words: light emitting diode, field effect transistor, bandgap width, solid state relays, photoelectric effect