Quantum confinement: mechanism for visible electroluminescence from spark-processed silicon

Abstract

Visible electroluminescence, (EL) showing a broad spectrum with several peaks, occurs from spark-processed silicon. High resolution scanning tunneling microscopy shows that the surface is composed of many small particles, with a significant fraction in the range of two nm required for bandgap enlargement. Hence quantum confinement effects can explain the blue shift of the EL spectrum. The devices show durability, and applications for optical communication between Si wafers appear possible.