Quantum size effects on photoluminescence in ultrafine Si particles

Abstract

Visible photoluminescence was observed in ultrafine Si particles at room temperature. Transmission electron microscopy revealed that Si microcrystallites were embedded in a Si oxide matrix for the sample which emitted the light. The emission energy depended on crystallite size in the range from 2.8 to 5 nm. The inverse relation between emission energy and the square of the crystallite size indicates that carrier confinement in the Si microcrystallites causes this photoluminescence phenomenon.