A stacked multi-junction solar cell having a first subcell and second subcell, the second subcell having a larger band gap than the first subcell. A third subcell has a larger band gap than the second subcell, and each of the subcells include an emitter and a base. The second subcell has a layer which includes a compound formed at least the elements GaInAsP, and a thickness of the layer is greater than 100 nm, and the layer is formed as part of the emitter and/or as part of the base and/or as part of the space-charge zone situated between the emitter and the base. The third subcell has a layer including a compound formed of at least the elements GaInP, and the thickness of the layer is greater than 100 nm.

A monolithic multijunction solar cell having exactly four subcells, an uppermost first subcell having a layer made up of a component having the elements AlInP, and the lattice constant a1 of the layer being between 0.572 nm and 0.577 nm, and the indium content being between 64% and 75%, and the Al content being between 18% and 32%, and the third subcell having a layer made up of a compound having at least the elements GaInAs, and the lattice constant of the layer being between 0.572 and 0.577, and the indium content of the layer being greater than 17%, and the second subcell comprising a layer including a compound which has at least the elements GaInAsP, the layer having an arsenic content between 22% and 33% and an indium content between 52% and 65%. and the lattice constant a2 being between 0.572 and 0.577.

A space-qualified solar cell assembly comprising a plurality of space-qualified solar cells mounted on a support, the support comprising a plurality of conductive vias extending from the top surface to the rear surface of the support. Each one of the pluralities of space-qualified solar cells is placed on the top surface with the first contact of a first polarity of the space-qualified solar cell electrically connected to the first conductive via. A second contact of a second polarity of each space-qualified solar cell can be connected to a second conductive via so that the first and second conductive portions form terminals of opposite conductivity type. The space-qualified solar cells on the module can be interconnected to form a string or an electrical series and/or parallel connection by suitably interconnecting the terminal pads of the vias on the back side of the module.

A space-qualified solar cell assembly comprising a plurality of space-qualified solar cells mounted on a support, the support comprising a plurality of conductive vias extending from the top surface to the rear surface of the support. Each one of the pluralities of space-qualified solar cells is placed on the top surface with the first contact of a first polarity of the space-qualified solar cell electrically connected to the first conductive via. A second contact of a second polarity of each space-qualified solar cell can be connected to a second conductive via so that the first and second conductive portions form terminals of opposite conductivity type. The space-qualified solar cells on the module can be interconnected to form a string or an electrical series and/or parallel connection by suitably interconnecting the terminal pads of the vias on the back side of the module.

An inverted metamorphic multijunction solar cell comprising: an upper first solar subcell having a first band gap; a middle second solar subcell disposed adjacent to the upper first solar subcell and having a second band gap smaller than said first band gap; a graded interlayer disposed adjacent to the middle second solar subcell and having a band gap that remains constant throughout its thickness; a lower third solar subcell disposed adjacent to said graded interlayer and having a fourth band gap that is smaller than said second band gap such that said third solar subcell is lattice mismatched with respect to said second solar subcell; a back surface field (BSF) layer disposed directly adjacent to the base layer of said lower third solar subcell; at least one distributed Bragg reflector (DBR) layer disposed directly adjacent to the back surface field (BSF) layer.

An inverted metamorphic multijunction solar cell comprising: an upper first solar subcell having a first band gap; a middle second solar subcell disposed adjacent to the upper first solar subcell and having a second band gap smaller than said first band gap; a graded interlayer disposed adjacent to the middle second solar subcell and having a band gap that remains constant throughout its thickness; a lower third solar subcell disposed adjacent to said graded interlayer and having a fourth band gap that is smaller than said second band gap such that said third solar subcell is lattice mismatched with respect to said second solar subcell; a back surface field (BSF) layer disposed directly adjacent to the base layer of said lower third solar subcell; at least one distributed Bragg reflector (DBR) layer disposed directly adjacent to the back surface field (BSF) layer.

A solar cell optimized for performance at high radiation doses, wherein the solar cell includes: a sub-cell comprised of a base and an emitter; the base of the sub-cell has a thickness of about 2 to 3 m; the base of the sub-cell is doped at about 1e14 cm.sup.3 to 1e16 cm.sup.3; and a reflector is inserted behind the sub-cell to maximize current generated by the sub-cell.

A solar cell optimized for performance at high radiation doses, wherein the solar cell includes: a sub-cell comprised of a base and an emitter; the base of the sub-cell has a thickness of about 2 to 3 m; the base of the sub-cell is doped at about 1e14 cm.sup.3 to 1e16 cm.sup.3; and a reflector is inserted behind the sub-cell to maximize current generated by the sub-cell.

An electrical connection is formed between first and second conductive elements, by inserting a nano-metal material between the first and second conductive elements; and heating the nano-metal material to a melting temperature to form the electrical connection between the first and second conductive elements. The nano-metal material may comprise a nano-metal paste or ink comprised of one or more of Gold (Au), Copper (Cu), Silver (Ag), and/or Aluminum (Al) nano-particles that melt or fuse into a solid to form the electrical connection, at a melting temperature of about 150-250 degrees C., and more preferably, about 175-225 degrees C. The electrical connection may be formed between a solar cell and a substrate by creating a via in the solar cell between a front and back side of the solar cell, wherein the via is connected to a contact on the front side of the solar cell and a trace on the substrate.

An antenna array has a plurality of square or rectangular antenna assemblies. Each assembly includes a first antenna assembly surface with a solar cell and a second antenna assembly with one or more antenna elements. The antenna assemblies are interconnected without gaps therebetween to form a first contiguous array surface comprised of the first antenna assembly surfaces and a second contiguous array surface comprised of the second antenna assembly surfaces. The antenna assemblies are connected together by mechanically stored-energy connectors, such as spring tape, that self-deploy the array in space without the use of electric energy.