Patent ID: 7119358

Claim:
A semiconductor structure for use in the near infrared region, preferably in the range from 1.3 to 1.6 μm, said structure comprising: an active zone consisting of a plurality of epitaxially grown alternating layers of Si and Ge which form a superlattice, a base layer of a first conductivity type disposed on one side of said active zone, a cladding layer of the opposite conductivity type to the base layer, the cladding layer being provided on the opposite side of said active zone from said base layer, wherein the Ge layers of the active zone each comprise a relatively thin layer of Germanium material and a plurality of spaced apart islands or accumulations of Germanium, each island having a relatively greater thickness than said thin layer, said islands forming quantum dots providing quantized energy levels for holes, and wherein the thickness of each silicon layer of said active zone is less than 5 nm, so that said holes are located in quantized energy levels associated with a valance band and electrons are localized in a miniband associated with the conduction band and resulting from the superlattice structure such that a direct transition between said miniband and said valence band is possible for charge carriers and light emission is based upon interband transitions.