A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein at least one of the solar subcells has a graded band gap throughout the thickness of at least a portion of the active layer of the one solar subcell.

A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein at least one of the solar subcells has a graded band gap throughout the thickness of at least a portion of the active layer of the one solar subcell.

The present disclosure relates to a photovoltaic (PV) device that includes a first junction constructed with a first alloy and having a bandgap between about 1.0 eV and about 1.5 eV, and a second junction constructed with a second alloy and having a bandgap between about 0.9 eV and about 1.3 eV, where the first alloy includes III-V elements, the second alloy includes III-V elements, and the PV device is configured to operate in a thermophotovoltaic system having an operating temperature between about 1500° C. and about 3000° C.

The present disclosure relates to a photovoltaic (PV) device that includes a first junction constructed with a first alloy and having a bandgap between about 1.0 eV and about 1.5 eV, and a second junction constructed with a second alloy and having a bandgap between about 0.9 eV and about 1.3 eV, where the first alloy includes III-V elements, the second alloy includes III-V elements, and the PV device is configured to operate in a thermophotovoltaic system having an operating temperature between about 1500° C. and about 3000° C.

Disclosed is a method of manufacturing a III-V group nanorod solar cell so that a substrate can be reused. The method may includes a first growth process of forming an etch stop layer on a substrate, a second growth process of growing a sacrificial layer on the etch stop layer, a third growth process of forming, on the sacrificial layer, a pattern layer including an opening at each location at which each nanorod solar cell is able to be grown, a fourth growth process of growing the nanorod solar cells on the sacrificial layer through the openings within the pattern layer, a forming process of forming a solar cell protection layer on outsides of the nanorod solar cells, a first etching process of etching the sacrificial layer and the pattern layer, and a second etching process of etching the etch stop layer.

Disclosed is a method of manufacturing a III-V group nanorod solar cell so that a substrate can be reused. The method may includes a first growth process of forming an etch stop layer on a substrate, a second growth process of growing a sacrificial layer on the etch stop layer, a third growth process of forming, on the sacrificial layer, a pattern layer including an opening at each location at which each nanorod solar cell is able to be grown, a fourth growth process of growing the nanorod solar cells on the sacrificial layer through the openings within the pattern layer, a forming process of forming a solar cell protection layer on outsides of the nanorod solar cells, a first etching process of etching the sacrificial layer and the pattern layer, and a second etching process of etching the etch stop layer.

A photovoltaic device configured to substantially avoid radiative recombination of photo-generated carriers, reduce loss of energy of the photo-generated carriers through the phonon emission, extract photo-generated carriers substantially exclusively from the multi-frequency satellite valley(s) of the bandstructure of the used semiconductor material as opposed to the single predetermined extremum of the bandstructure. Methodologies of fabrication and operation of such a device.

A photovoltaic device configured to substantially avoid radiative recombination of photo-generated carriers, reduce loss of energy of the photo-generated carriers through the phonon emission, extract photo-generated carriers substantially exclusively from the multi-frequency satellite valley(s) of the bandstructure of the used semiconductor material as opposed to the single predetermined extremum of the bandstructure. Methodologies of fabrication and operation of such a device.

A metamorphic multijunction solar cell having a growth semiconductor substrate with a top surface having a doping in the range of 1x10.sup.18 to 1x10.sup.20 charge carriers/cm.sup.3; a window layer for a top (light facing) subcell formed directly on the top surface of the growth substrate; a sequence of layers of semiconductor material forming a solar cell directly on the window layer; a surrogate substrate on the top surface of the sequence of layers of semiconductor material, wherein a portion of the semiconductor substrate is removed so that only the high doped surface portion of the substrate, having a thickness in the range of 0.5 μm to 10 μm, remains.

A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein at least one of the solar cells has a graded band gap throughout its thickness.