Amorphous silicon quantum dots (a-Si QDs), which show a quantum confinement effect, were grown in a silion nitride film by plasma enhanced chemical vapor deposition. Red, green, blue, and white photolumiscence were observed from the a-Si QD strictures by controlling the fot size. An organe light-emitting device (LED) was fabricated using a-Si QDs with a mean size of 2.0 nm. The turn-on vottage was less than 5 V. An external quantum effiency of 2×10−3 % was also demonstrated. These results show that an LED using a-Si QDs embedded in the silicon nitride film is superior in terms of electrical and optical properties to other Si-based LEDs.