Low cost fabrication of blue luminescent silicon quantum dots using photo-induced chemical etching

Blue luminescent silicon quantum dots, strongly absorbing at short wavelengths, were fabricated by photo-induced chemical etching. To decrease the production cost, recycled Si ingot sawing waste was used as the starting material. Increasing the reaction time decreased the quantum dot size from 2 m to 1.5-3.0 nm. Control of particle size was possible by adjusting the incident photon energy. The average size of the quantum dots produced at radiation wavelengths <500 nm was estimated to be 2.3±0.5 nm. Strong blue photoluminescence emission was detected at 475 nm, exhibiting an intensity maximum due to the quantum confinement effect.