Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge

A multi-junction, monolithic, photovoltaic solar cell device grown on a crystalline substrate and configured for use in an electrical circuit for converting photons from the sun into electrical current and voltage, said solar cell device comprising:

• a first active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers is fabricated from a material selected from the group consisting of (GaAs)x(Ge2)1−x, BxGayIn1−x−yAs, CuInSxSe2−x, and Cu3AsSxSe4−x and has a lattice constant substantially equal to a lattice constant of GaAs or Ge and, further, wherein said first active cell has a band gap greater than about 0.67 eV and less than about 1.3 eV;
• a second active cell positioned adjacent said first active cell, said second active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers is fabricated from a material selected from the group consisting of GaxIn1−xAsyP1−y, GaxIn1−xNyP1−y, AlxGa1−xAs, and GaxIn1−xAsyNzP1−y−z, and has a lattice constant substantially equal to said lattice constant of said semiconductor layers of said first active cell and, further, wherein said junction of said second active cell has a band gap in the range of 1.3 to 1.8 eV;
• and
• a tunnel junction layer interposed between said first active cell and said second active cell, said tunnel junction layer comprising materials for facilitating current flow between said first active cell and said second active cell.

A multi-junction, monolithic, photovoltaic solar cell device grown on a crystalline substrate and configured for use in an electrical circuit for converting photons from the sun into electrical current and voltage, said solar cell device comprising:

• a first active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers is semiconductor layers of said first active cell are fabricated from a material selected from the group consisting of Ge and (GaAs)x(Ge2)1−x and has a lattice constant substantially equal to a lattice constant of GaAs or Ge and wherein said first active cell has a band gap greater than about 0.67 eV and less than about 0.9 eV;
• a second active cell positioned adjacent said first active cell, said second active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers is fabricated from a material selected from the group consisting of GaxIn1−xAsyN1−y, (GaAs)x(Ge2)1−x, BxGayIn1−x−yAs, CuInSxSe2−x, and Cu3AsSxSe4−x and has a lattice constant substantially equal to said lattice constant of said semiconductor layers of said first active cell and wherein said second active cell has a band gap in the range of about 1.1 eV to about 1.2 eV;
• and
• a third active cell positioned adjacent said second active cell, said third active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers is fabricated from a material selected from the group consisting of GaxIn1−xAsyP1−y, GaxIn1−xNyP1−y, AlxGa1−xAs, and GaxIn1−xasyNzP1−y−z, and further has a lattice constant substantially equal to said lattice constant of said semiconductor layers of said second active cell and wherein said third active cell has a band gap in the range of about 1.6 eV to about 1.9 eV.

A multi-junction, monolithic, photovoltaic solar cell device grown on a crystalline substrate and configured for use in an electrical circuit for converting photons from the sun into electrical current and voltage, and said solar cell device comprising:

• a first active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers of said first active cell is fabricated from a material selected from the group consisting of (GaAs)x(Ge2)1−x, BxGayIn1−x−yAs, CuInSxSe2−x, and Cu3AsSxSe4−x and has a lattice constant substantially equal to a lattice constant of GaA or Ge and wherein said first active cell has a band gap in the range of about 0.9 eV to about 1.1 eV;
• a second active cell positioned adjacent said first active cell, said second active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers of said second active cell is fabricated from a material selected from the group consisting of GaAs, GaxIn1−xAsyN1−y, AlxGa1−xAs, and GaxIn1−xAsyP1−y and has a lattice constant substantially equal to said lattice constant of said semiconductor layers of said first active cell, and wherein said second active cell has a band gap in the range of 1.3 to 1.5 eV;
• and
• a third active cell positioned adjacent said second active cell, said third active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers of said third active cell is fabricated from a material selected from the group consisting of Ga0.5In0.5P, AlxGa1−xAs, and AlxGa0.5−xIn0.5P and has a lattice constant substantially equal to said lattice constant of said semiconductor layers of said second active cell, and wherein said second active cell has a band gap in the range of 1.8 to 2.0 eV.

A multi-junction, monolithic, photovoltaic solar cell device grown on a crystalline substrate of Ge or GaAs and configured for use in an electrical circuit for converting photons from the sun into electrical current and voltage, said solar cell device comprising:

• a first active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers has a lattice constant substantially equal to a lattice constant of GaAs or Ge and wherein said first active cell has a band gap greater than about 0.67 eV;
• a second active cell positioned adjacent said first active cell, said second active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers has a lattice constant substantially equal to said lattice constant of said semiconductor layers of said first active cell and wherein said second active cell has a band gap in the range of about 1.1 eV to about 1.5 eV;
• and
• a third active cell positioned adjacent said second active cell, said third active cell comprising a junction of at least one p-type semiconductor layer in face-to-face contact with one n-type semiconductor layer, wherein each of said semiconductor layers has a lattice constant substantially equal to said lattice constant of said semiconductor layers of said second active cell and a band gap in the range of about 1.6 eV to about 2.0 eV, and wherein said semiconductor layers of said third active cell are fabricated from a group consisting of Ga0.5In0.5P and AlxGa1−xAs.