Low-voltage silicon (Si)-based light-emitting diode (LED) is designed based on the former research of LED in Si-based standard complementary metal oxide semiconductor (CMOS) technology. The low-voltage LED is designed under the research of cross-finger structure LEDs and sophisticated structure enhanced LEDs for high efficiency and stable light source of monolithic chip integration. The device size of low-voltage LED is 45.85\times 38.4 (\mu m), threshold voltage is 2.2 V in common condition, and temperature is 27 oC. The external quantum efficiency is about 10^{-6} at stable operating state of 5 V and 177 mA.