The Boeing Company

Hughes Aircraft Company

Hughes Electronics Corporation

David E Joslin

Christopher M Fetzer

Richard Roland King

Dmitri D Krut

Nasser H Karam

David R Lillington

Methods and apparatuses for a dual heterojunction multijunction solar cell are disclosed. A method in accordance with the present invention comprises growing a base material for a solar cell, growing at least one dual heterojunction on the base material, and growing an emitter on the at least one dual heterojunction. An apparatus in accordance with the present invention comprises a substrate, and a first subcell, coupled to the substrate, wherein the first subcell comprises a base region, coupled to the substrate, an emitter region, and at least one dual heterojunction, coupled between the base region and the emitter region, wherein the at least one dual heterojunction has a lower bandgap than the emitter region.

Reduced band gap absorber for solar cells

A solar cell array has at least one solar cell including a photovoltaic structure having a sun-facing front face and a back face, and having an active region, and an isotype heterojunction diode connected in electrical parallel with the active region of the photovoltaic structure.

Solar cell array with isotype-heterojunction diode

A multijunction photovoltaic cell comprises a first subcell that initially receives incident light upon the photovoltaic cell, with the first subcell being made of a first material system, having a first thickness, and producing a first photogenerated current output. A second subcell receives the incident light after the first subcell receives the incident light, with the second subcell being disposed immediately adjacent the first subcell. The second subcell is made of the first material system or a similar semiconductor material, has a second thickness that is greater than the first thickness, and produces a second photogenerated current output that is substantially equal in amount to the first photogenerated current output. A tunnel junction is disposed between the first and second subcells. The multijunction cell provides a greater ability to current match to low-current-producing subcells, higher multijunction cell voltage, lower series resistance, and greater radiation resistance.

Multijunction photovoltaic cell with thin 1st (top) subcell and thick 2nd subcell of same or similar semiconductor material

A two-terminal voltage or current matched solar cell has up to four photovoltaically active junctions which efficiently convert solar radiation into electricity. The solar cell comprises GaInP, GaAs, and GaInAsP, and in the four junction case, GaInAs is used as well. The invention allows the solar spectrum to be converted into electricity more efficiently than previously.

High efficiency multi-junction solar cells

Laser apparatus comprising a support that is operative as a heat sink, a diode laser bar assembly, a metallized insulating layer disposed between the substrate and laser bar assembly and an interconnection layer adapted to couple the substrate to the laser bar assembly by means of the metalized insulating layer. The diode laser bar assembly comprises a plurality of laser diode bars having a plurality of lasing sections formed along a lateral edge thereof. First and second metal contacts are disposed on respective adjacent lateral edges of adjacent diode bars, and the metal contacts are separated by a thin layer of metal alloy. One contact forms a positive electrical contact for one laser bar, and the other metal contact forms a negative contact for the adjacent laser bar. A dielectric mirror is disposed on a bottom surface of each of the laser diode bars and an antireflection coating disposed on a top surface of each of the laser diode bars. The present laser apparatus reduces the complexity and cost of diode laser arrays and provides for increased peak power output and improved heat removal. The present diode laser bar assembly may be used in laser surgery systems, solid laser welding, and x-ray photolithography systems where giant pulse solid state lasers are used to create plasmas that generate x-rays. The advantages provided by the diode laser bar assembly are longevity, less heat generation in solid state lasers that are pumped, and greater overall conversion efficiency.

Growing community of inventors

Valley Village, CA, United States of America

David E Joslin