Light emission from Si/SiO/sub 2/ nanostructures

Various kinds of nanostructures are made utilizing molecular beam deposition, ion implantation, and PECVD accompanied by different annealing procedures. MOS-type light emitting devices are made and their luminescent as well as electrical properties are studied. Emission spectrum extends from red to blue depending on fabrication conditions. The red part is associated with silicon nano-clusters. It can be understood by quantum confinement model taking into account surface chemistry of clusters. The same model may also explain the blue part the alternative being emission from defects in oxide. Current conduction is shown to take place by inelastic tunneling of electrons between clusters. The inelastic process also provides EL excitation mechanism leading to a linear relationship between emission intensity and current.