The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 06, 1997
Filed:
Jun. 01, 1995
Leigh-Trevor Canham, Worcestershire, GB;
John M Keen, Worcestershire, GB;
Weng Y Leong, Worcestershire, GB;
Abstract
A method of making semiconductor quantum wires, and a light emitting device employing such wires, employs a semiconductor wafer as starting material. The wafer is weakly doped p type with a shallow heavily doped p layer therein for current flow uniformity purposes. The wafer is anodized in 20% aqueous hydrofluoric acid to produce a layer 5 microns thick with 70% porosity and good crystallinity. The layer is subsequently etched in concentrated hydrofluoric acid, which provides a slow etch rate. The etch increases porosity to a level in the region of 80% or above. At such a level, pores overlap and isolated quantum wires are expected to form with diameters less than or equal to 3 nm. When excited, the etched layer exhibits photoluminescence emission at photon energies well above the silicon bandgap (1.1 eV) and extending into the red region (1.6-2.0 eV) of the visible spectrum.