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AssigneeThe Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
InventorsLeigh-Trevor Canham, John M. Keen, Weng Y. Leong
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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.
A light emitting device comprising:
A luminescent device comprising silicon material at least a portion of which comprises porous silicon, said porous silicon having a porosity of at least 60% and incorporating silicon quantum wires, wherein the porous silicon is luminescent at a temperature of 300K and luminescence from the device is visible.
A luminescent device comprising silicon material at least a portion of which comprises porous silicon, said porous silicon having a porosity of at least 60% and incorporating silicon quantum wires having a thickness of less than 3 nm, wherein the porous silicon is luminescent at a temperature of 300K and luminescence from the device is visible.
Luminescent porous silicon having a porosity of at least 60% and wherein the porous silicon is visibly luminescent at a temperature of 300K.
A silicon composite structure comprising:
A light emitting device comprising:
Dependencies are inferred from the claim text.