An inverted metamorphic multijunction solar cell including an upper first solar subcell, a second solar subcell and a third solar subcell. The upper first solar subcell has a first band gap and positioned for receiving an incoming light beam. The second solar subcell is disposed below and adjacent to, and is lattice matched with, the upper first solar subcell, and has a second band gap smaller than the first band gap. The third solar subcell is disposed below the second solar subcell, and is composed of a GaAs base and emitter layer so as to optimize the efficiency of the solar cell after exposure to radiation. In some implementations, at least one of the solar subcells has a graded band gap throughout its thickness.

An inverted metamorphic multijunction solar cell including an upper first solar subcell, a second solar subcell and a third solar subcell. The upper first solar subcell has a first band gap and positioned for receiving an incoming light beam. The second solar subcell is disposed below and adjacent to, and is lattice matched with, the upper first solar subcell, and has a second band gap smaller than the first band gap. The third solar subcell is disposed below the second solar subcell, and is composed of a GaAs base and emitter layer so as to optimize the efficiency of the solar cell after exposure to radiation. In some implementations, at least one of the solar subcells has a graded band gap throughout its thickness.

Manufacture of multi-junction solar cells, and devices thereof, are disclosed. The architectures are also adapted to provide for a more uniform and consistent fabrication of the solar cell structures, leading to improved yields, greater efficiency, and lower costs. Certain solar cells may be from a different manufacturing process and further include one or more compositional gradients of one or more semiconductor elements in one or more semiconductor layers, resulting in a more optimal solar cell device.

Manufacture of multi-junction solar cells, and devices thereof, are disclosed. The architectures are also adapted to provide for a more uniform and consistent fabrication of the solar cell structures, leading to improved yields, greater efficiency, and lower costs. Certain solar cells may be from a different manufacturing process and further include one or more compositional gradients of one or more semiconductor elements in one or more semiconductor layers, resulting in a more optimal solar cell device.

A photoelectric conversion device includes: a wavelength converting region that absorbs ambient light to generate electrons and holes, and recombines the generated electrons and holes to generate monochromatic light; and a photoelectric conversion region that has a p-n junction or p-i-n junction, absorbs the monochromatic light generated in the wavelength converting region to generate electrons and holes, and separates and moves the electrons and holes generated by absorption of the monochromatic light. The wavelength converting region includes: a carrier generating region that generates the electrons and holes; a light emitting region that generates the monochromatic light; and a carrier selective transfer region that is disposed between the carrier generating region and the light emitting region and that, of the electrons and holes generated in the carrier generating region, moves those electrons and holes having specific energies difference there between to the light emitting region.

A thin-film solar cell comprising a substrate, a first electrode layer arranged upon the substrate, a p-type light absorption layer formed by a group I-III-IV.sub.2 compound arranged upon the first electrode layer, and an n-type second electrode layer arranged upon the p-type light absorption layer. The p-type light absorption layer includes Cu as a group 1 element and includes Ga and In as group III elements. The ratio of the atomic number between Cu and the group III elements in the entire p-type light absorption layer is lower than 1.0; the ratio of the atomic number between Ga and the group III elements in the surface on the second electrode layer side is no more than 0.13; and the ratio of the atomic number between Cu and the group III elements in the surface on the second electrode layer side is at least 1.0.

A thin-film solar cell comprising a substrate, a first electrode layer arranged upon the substrate, a p-type light absorption layer formed by a group I-III-IV.sub.2 compound arranged upon the first electrode layer, and an n-type second electrode layer arranged upon the p-type light absorption layer. The p-type light absorption layer includes Cu as a group 1 element and includes Ga and In as group III elements. The ratio of the atomic number between Cu and the group III elements in the entire p-type light absorption layer is lower than 1.0; the ratio of the atomic number between Ga and the group III elements in the surface on the second electrode layer side is no more than 0.13; and the ratio of the atomic number between Cu and the group III elements in the surface on the second electrode layer side is at least 1.0.

The invention bears on elementary nanoscale units nanostructured-formed inside a silicon material and the manufacturing process to implement them. Each elementary nanoscale unit is created by means of a limited displacement of two Si atoms outside a crystal elementary unit. A localized nanoscale transformation of the crystalline matter gets an unusual functionality by focusing in it a specific physical effect as is a highly useful additional set of electron energy levels that is optimized for the solar spectrum conversion to electricity. An adjusted energy set allows a low-energy secondary electron generation in a semiconductor, preferentially silicon, material for use especially in very-high efficiency all-silicon light-to-electricity converters. The manufacturing process to create such transformations in a semiconductor material bases on a local energy deposition like ion implantation or electron (γ,X) beam irradiation and suitable thermal treatment and is industrially easily available.

The invention bears on elementary nanoscale units nanostructured-formed inside a silicon material and the manufacturing process to implement them. Each elementary nanoscale unit is created by means of a limited displacement of two Si atoms outside a crystal elementary unit. A localized nanoscale transformation of the crystalline matter gets an unusual functionality by focusing in it a specific physical effect as is a highly useful additional set of electron energy levels that is optimized for the solar spectrum conversion to electricity. An adjusted energy set allows a low-energy secondary electron generation in a semiconductor, preferentially silicon, material for use especially in very-high efficiency all-silicon light-to-electricity converters. The manufacturing process to create such transformations in a semiconductor material bases on a local energy deposition like ion implantation or electron (γ,X) beam irradiation and suitable thermal treatment and is industrially easily available.

Embodiments of a photovoltaic device are provided herein. The photovoltaic device can include a layer stack and an absorber layer disposed on the layer stack. The absorber layer can include a first region and a second region. Each of the first region of the absorber layer and the second region of the absorber layer can include a compound comprising cadmium, selenium, and tellurium. An atomic concentration of selenium can vary across the absorber layer. The first region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. The second region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. A ratio of an average atomic concentration of selenium in the first region of the absorber layer to an average atomic concentration of selenium in the second region of the absorber layer can be greater than 10.