Abstract: An ultraviolet semiconductor light emitting device includes: a light-emitting epitaxial layer including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer; a tunnel junction at a non-light-emitting surface of the light-emitting epitaxial layer and having a patterned structure with openings to expose the light-emitting epitaxial layer; an optical phase matching layer over a surface layer of the light-emitting epitaxial layer and transmissive of UV light; and a reflecting layer covering the entire tunneling junction and the optical phase matching layer. A patterned structure is provided over the tunnel junction for full-angle light reflection. Part of the tunneling junction forms ohmic contact with the low work function reflecting metal. The patterned distribution design can effectively reduce the ohmic contact resistance.

Abstract: An ultraviolet semiconductor light emitting device includes: a light-emitting epitaxial layer including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer; a tunnel junction at a non-light-emitting surface of the light-emitting epitaxial layer and having a patterned structure with openings to expose the light-emitting epitaxial layer; an optical phase matching layer over a surface layer of the light-emitting epitaxial layer and transmissive of UV light; and a reflecting layer covering the entire tunneling junction and the optical phase matching layer. A patterned structure is provided over the tunnel junction for full-angle light reflection. Part of the tunneling junction forms ohmic contact with the low work function reflecting metal. The patterned distribution design can effectively reduce the ohmic contact resistance.

Abstract: A high-concentration solar cell includes an epitaxial layer structure, an upper patterned electrode on the top surface, and a back electrode on the back surface. The upper patterned electrode includes a primary pattern and a secondary pattern, where the primary pattern is composed of a series of small metal isosceles trapezoids around the perimeter of the cell. The narrower base of each metal trapezoid points toward an interior of the cell. A lead soldering pad is located within each metal trapezoid for being soldered to an external conductor for carrying the solar cell current. The secondary pattern consists of thin spaced conductors that connect to the angled sides and base of each trapezoid and spread current across the top surface of the cell. The current along the angled sides of each trapezoid is well-distributed to all the spaced conductors connected to the angled sides to avoid current crowding.

Abstract: A high-concentration solar cell includes an epitaxial layer structure, an upper patterned electrode on the top surface, and a back electrode on the back surface. The upper patterned electrode includes a primary pattern and a secondary pattern, where the primary pattern is composed of a series of small metal isosceles trapezoids around the perimeter of the cell. The narrower base of each metal trapezoid points toward an interior of the cell. A lead soldering pad is located within each metal trapezoid for being soldered to an external conductor for carrying the solar cell current. The secondary pattern consists of thin spaced conductors that connect to the angled sides and base of each trapezoid and spread current across the top surface of the cell. The current along the angled sides of each trapezoid is well-distributed to all the spaced conductors connected to the angled sides to avoid current crowding.