Epitaxial Growth of Electroluminescent Quantum Wires

The proposed program seeks to develop optical interconnects for advanced signal and data processors by relying solely on silicon technology for all optical and electronic functions. Epitaxial silicon quantum wires (QWRs) confined by suitable lattice-matched cladding layers will be grown by chemical vapor deposition on silicon substrates: these nanostructures should exhibit quantum size effect~ similar to "porous silicon," but advantageously will feature a organized growth habit with controlled dimensions. Although "porous silicon" produced by electrochemical etching shows bright visible photoluminescence, electroluminescence intensities remain poor due t enormous defect densities. Our QWR structures will have high crystalline perfection, allowing bright electroluminescence to be manifested. V-grooves formed in the silicon substrate should encourage the formation of triangular silicon wires due to anisotropic growth as previously demonstrated for GaAs/AlGaAs quantum wires. Cladding layers will be grown on specially cleaned silicon substrates, using (unique procedure developed at the University of Florida; the silicon films will be deposited at low temperatures thereon. Phase I will specify growth conditions to form silicon quantum wires, and to demonstrate strong, blue-shifted photoluminescence. In Phase II we shall prepare junction diodes which emit near-visible light under electrical bias. Because the QWRs will be configured as waveguides, we anticipate subsequent demonstration of arrays of silicon diode. Potential Commercial Applications of the Research or Development: Arrays of silicon quantum wires should yield valuable commercial devices including light-emitting diodes, laser diodes, photovoltaic detectors, and optical modulators. They afford the promise of true wafer scale integration of all optical and electronic device function in a single silicon wafer.