High efficiency multijunction solar cells

A photovoltaic cell comprising:

• a first subcell having a first base layer formed of a material selected from the group consisting of Ge, SiGe(Sn), and Ga1-xInxNyAs1-y-zSbz, in which values for x, y and z are 0.08≦x ≦0.24, 0.02≦y≦0.05 and 0.001≦z≦0.014, and characterized by a band gap of 0.7 eV to 1.1 eV;
• a second subcell having a second base layer overlying the first subcell, wherein the second base layer is formed of an alloy of one or more elements from group III on the periodic table, nitrogen, arsenic, and at least one element selected from the group consisting of Sb and Bi, and characterized by a band gap of 0.9 eV to 1.3 eV;
• a third subcell having a third base layer overlying the second subcell, wherein the third base layer is formed of a material selected from the group consisting of GaInPAs and (Al,In)GaAs, and characterized by a band gap from 1.4 eV to 1.7 eV;
• and
• a fourth subcell having a fourth base layer overlying the third subcell, wherein the fourth base layer is formed of (Al)InGaP and characterized by a band gap from 1.9 eV to 2.2 eV;
• wherein the first base layer, the second base layer, or the first base layer and the second base layer are formed of Ga1-xInxNyAs1-y-zSbz, in which values for x, y and z are 0.08≦x ≦0.24, 0.02≦y≦0.05 and 0.001≦z≦0.014.

A photovoltaic cell comprising:

• a first subcell having a first base layer formed of a material selected from the group consisting of Ge, SiGe(Sn) and Ga1-xInxNyAs1-y-zSbz, in which values for x, y and z are 0.08≦x ≦0.24, 0.02≦y≦0.05 and 0.001≦z≦0.014, and characterized by a band gap of 0.7 eV to 1.1 eV;
• a second subcell having a second base layer overlying the first subcell, wherein the second base layer is formed of an alloy of one or more elements from group III on the periodic table, nitrogen, arsenic, and at least one element selected from the group consisting of Sb and Bi, and characterized by a band gap of 0.9 eV to 1.3 eV;
• a third subcell having a third base layer overlying the second subcell, wherein the third base layer is formed of a material selected from the group consisting of GaInPAs, (Al,In)GaAs, and an alloy of one or more elements from group III on the periodic table, nitrogen, arsenic, and at least one element selected from the group consisting of Sb and Bi, and characterized by a band gap of 1.2 eV to 1.6 eV;
• a fourth subcell having a fourth base layer overlying the third subcell, wherein the fourth base layer is formed of a material selected from the group consisting of GaInPAs and (Al,In)GaAs, and characterized by a band gap from 1.6 eV to 1.9 eV;
• and
• a fifth subcell having a fifth base layer overlying the fourth subcell, wherein the fifth base layer is formed of (Al)InGaP and characterized by a band gap from 1.9 eV to 2.2 eV;
• wherein the first base layer, the second base layer, or the first base layer and the second base layer are formed of Ga1-xInxNyAs1-y-zSbz, in which values for x, y and z are 0.08≦x ≦0.24, 0.02≦y≦0.05 and 0.001≦z≦0.014.

A photovoltaic cell comprising:

• a first subcell having a first base layer formed of a material selected from the group consisting of Ge, SiGe(Sn), and Ga1-xInxNyAs1-y-zSbz, in which values for x, y and z are 0.08≦x ≦0.24, 0.02≦y≦0.05 and 0.001≦z≦0.014, and characterized by a band gap of 0.7 eV to 1.1 eV;
• a second subcell having a second base layer overlying the first subcell, wherein the second base layer is formed of an alloy of one or more elements from group III on the periodic table, nitrogen, arsenic, and at least one element selected from the group consisting of Sb and Bi, and characterized by a band gap of 0.9 eV to 1.3 eV;
• a third subcell having a third base layer overlying the second subcell, wherein the third base layer is formed of a material selected from the group consisting of GaInPAs, (Al,In)GaAs, and an alloy of one or more elements from group III on the periodic table, nitrogen, arsenic, and at least one element selected from the group consisting of Sb and Bi, and characterized by a band gap of 1.1 eV to 1.5 eV;
• a fourth subcell having a fourth base layer overlying the third subcell, wherein the fourth base layer is formed of a material selected from the group consisting of (Al,In)GaAs and (Al)InGa(P)As, and characterized by a band gap from 1.4 eV to 1.7 eV;
• a fifth subcell having a fifth base layer overlying the fourth subcell, wherein the fifth base layer is formed of a material selected from the group consisting of (Al)InGaP and Al(In)Ga(P)As, and characterized by a band gap from 1.6 eV to 2.0 eV;
• and
• a sixth subcell having a sixth base layer overlying the fifth subcell, wherein the sixth base layer is formed of (Al)InGaP, and characterized by a band gap from 1.9 eV to 2.3 eV;
• wherein the first base layer, the second base layer, or the first base layer and the second base layer are formed of Ga1-xInxNyAs1-y-zSbz, in which values for x, y and z are 0.08≦x ≦0.24, 0.02≦y≦0.05 and 0.001≦z≦0.014.