A tandem photovoltaic device includes: an upper cell unit, a lower cell unit and a tunnel junction positioned between the upper cell unit and the lower cell unit; the tunnel junction includes an upper transport layer, a lower transport layer, and an intermediate layer positioned between the upper transport layer and the lower transport layer, the intermediate layer is an ordered defect layer, or, the intermediate layer is a continuous thin layer, or, the intermediate layer includes a first layer in contact with the lower transport layer and a second layer in contact with the upper transport layer; a doping concentration of the first layer is 10-10,000 times of a doping concentration of the lower transport layer, and the doping concentration of the first layer is less than 10.sup.21cm.sup.−3; a doping concentration of the second layer is 10-10,000 times of a doping concentration of the upper transport layer.

The photoelectric conversion layer of an embodiment is based on Cu.sub.2O, contains at least one p-type dopant selected from the group consisting of Ge, Ta, and In, and has a band gap of equal to or more than 2.10 eV and equal to or less than 2.30 eV.

A five junction solar cell and its method of manufacture including an upper first solar subcell composed of a semiconductor material having a first band gap; a second solar subcell adjacent to said first solar subcell and composed of a semiconductor material having a second band gap smaller than the first band gap and being lattice matched with the upper first solar subcell; a third solar subcell adjacent to said second solar subcell and composed of a semiconductor material having a third band gap smaller than the second band gap and being lattice matched with the second solar subcell; a fourth solar subcell adjacent to said second solar subcell and composed of a semiconductor material having a fourth band gap smaller than the third band gap and being lattice matched with respect to the third solar subcell; a graded interlayer adjacent to the fourth solar subcell and having a fifth band gap greater than the fourth band gap; and a bottom solar subcell adjacent to the graded interlayer and being lattice mismatched from the fourth solar subcell and having a sixth band gap smaller than the fifth band gap.

A five junction solar cell and its method of manufacture including an upper first solar subcell composed of a semiconductor material having a first band gap; a second solar subcell adjacent to said first solar subcell and composed of a semiconductor material having a second band gap smaller than the first band gap and being lattice matched with the upper first solar subcell; a third solar subcell adjacent to said second solar subcell and composed of a semiconductor material having a third band gap smaller than the second band gap and being lattice matched with the second solar subcell; a fourth solar subcell adjacent to said second solar subcell and composed of a semiconductor material having a fourth band gap smaller than the third band gap and being lattice matched with respect to the third solar subcell; a graded interlayer adjacent to the fourth solar subcell and having a fifth band gap greater than the fourth band gap; and a bottom solar subcell adjacent to the graded interlayer and being lattice mismatched from the fourth solar subcell and having a sixth band gap smaller than the fifth band gap.

A tandem photovoltaic device and production method. The tandem photovoltaic device includes: an upper battery cell and a lower battery cell, and a tunnel junction located between the upper battery cell and the battery cell; the lower battery is a crystalline silicon cell; the tunnel junction includes: an upper crystalline silicon layer, a lower crystalline silicon layer and an intermediate layer located between the upper crystalline silicon layer and the lower crystalline silicon layer; the upper crystalline silicon layer, the lower crystalline silicon layer and the intermediate layer are in direct contact, and the doping types of the upper crystalline silicon layer and the lower crystalline silicon layer are opposite; the doping concentration of the upper crystalline silicon layer at the interface with the intermediate layer and the doping concentration of the lower crystalline silicon layer at the interface with the intermediate layer are greater than or equal to 10.sup.18 cm.sup.−3.

A photovoltaic structure includes a substrate; and a plurality of off-axis, doped silicon regions outward of the substrate. The plurality of off-axis, doped silicon regions have an off-axis lattice orientation at a predetermined non-zero angle. A plurality of photovoltaic devices of a first chemistry are located outward of the plurality of off-axis, doped silicon regions. Optionally, a plurality of photovoltaic devices of a second chemistry, different than the first chemistry, are located outward of the substrate and are spaced away from the plurality of off-axis, doped silicon regions.

A photovoltaic structure includes a substrate; and a plurality of off-axis, doped silicon regions outward of the substrate. The plurality of off-axis, doped silicon regions have an off-axis lattice orientation at a predetermined non-zero angle. A plurality of photovoltaic devices of a first chemistry are located outward of the plurality of off-axis, doped silicon regions. Optionally, a plurality of photovoltaic devices of a second chemistry, different than the first chemistry, are located outward of the substrate and are spaced away from the plurality of off-axis, doped silicon regions.

Device structures, apparatuses, and methods are disclosed for photovoltaic cells that may be a single junction or multijunction solar cells, with at least one layer comprising a group-IV semiconductor in which part of the cell comprises a second layer comprising a III-V semiconductor or group-IV semiconductor having a different composition than the group-IV semiconductor of the first layer, such that a heterostructure is formed between the first and second layers.

Device structures, apparatuses, and methods are disclosed for photovoltaic cells that may be a single junction or multijunction solar cells, with at least one layer comprising a group-IV semiconductor in which part of the cell comprises a second layer comprising a III-V semiconductor or group-IV semiconductor having a different composition than the group-IV semiconductor of the first layer, such that a heterostructure is formed between the first and second layers.

A solar cell of an embodiment includes a p-electrode, a p-type light-absorbing layer containing a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode, an n-type layer on the p-type light-absorbing layer, and an n-electrode, when a first region is a region of the p-type light-absorbing layer from an interface between the p-type light absorbing layer and n-type layer to a depth of 10 nm toward the p-electrode and a second region is a region of the p-type light-absorbing layer from the interface between the p-type light absorbing layer and the n-type layer to a depth of 100 nm toward the p-electrode excluding the first region, a maximum intensity of an intensity profile of a HAADF-STEM image of the first region is 95% or more and 105% or less of an average intensity of an intensity profile of a HAADF-STEM of the second region.