Abstract: Multijunction photovoltaic cells having at least three subcells are disclosed, in which at least one of the subcells comprises a base layer formed of GaInNAsSb. The GaInNAsSb subcells exhibit high internal quantum efficiencies over a broad range of irradiance energies.

Abstract: Multijunction photovoltaic cells having at least three subcells are disclosed, in which at least one of the subcells comprises a base layer formed of GaInNAsSb. The GaInNAsSb subcells exhibit high internal quantum efficiencies over a broad range of irradiance energies.

Abstract: Dilute nitride optical absorber materials having graded doping profiles are disclosed. The materials can be used in photodetectors and photovoltaic cells. Dilute nitride subcells having graded doping display improved efficiency, short circuit current density, and open circuit voltage.

Abstract: A lattice-matched solar cell having a dilute nitride-based sub-cell has exponential doping to thereby control current-carrying capacity of the solar cell. Specifically a solar cell with at least one dilute nitride sub-cell that has a variably doped base or emitter is disclosed. In one embodiment, a lattice matched multi junction solar cell has an upper sub-cell, a middle sub-cell and a lower dilute nitride sub-cell, the lower dilute nitride sub-cell having doping in the base and/or the emitter that is at least partially exponentially doped so as to improve its solar cell performance characteristics. In construction, the dilute nitride sub-cell may have the lowest bandgap and be lattice matched to a substrate, the middle cell typically has a higher bandgap than the dilute nitride sub-cell while it is lattice matched to the dilute nitride sub-cell.

Abstract: Multijunction photovoltaic cells having at least three subcells are disclosed, in which at least one of the subcells comprises a base layer formed of GaInNAsSb. The GaInNAsSb subcells exhibit high internal quantum efficiencies over a broad range of irradiance energies.

Abstract: Compound semiconductor alloys comprising dilute nitride materials, are materials used in absorbing layers for photodetectors, power converters, solar cells, and in particular to high efficiency, electronic and optoelectronic devices, including multijunction solar cells, photodetectors, power converters, and the like, formed primarily of III-V semiconductor alloys. The absorbing (or active) layers achieve improved characteristics including band gap optimization and minimization of defects.

Abstract: Multijunction solar cells having at least four subcells are disclosed, in which at least one of the subcells comprises a base layer 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 each of the subcells is substantially lattice matched. Methods of manufacturing solar cells and photovoltaic systems comprising at least one of the multijunction solar cells are also disclosed.

Abstract: Multijunction photovoltaic cells having at least three subcells are disclosed, in which at least one of the subcells comprises a base layer formed of GaInNAsSb. The GaInNAsSb subcells exhibit high internal quantum efficiencies over a broad range of irradiance energies.

Abstract: A multi junction solar cell is provided with a non-alloyed ohmic contact metallization stack by inversion of the top semiconductor layer from n-type to p-type and including the utilization of a tunnel junction. Alternatively, the non-alloyed ohmic contact can be achieved by changing the top semiconductor layer from a higher bandgap material to a lower bandgap material.

Abstract: A lattice-matched solar cell having a dilute nitride-based sub-cell has exponential doping to thereby control current-carrying capacity of the solar cell. Specifically a solar cell with at least one dilute nitride sub-cell that has a variably doped base or emitter is disclosed. In one embodiment, a lattice matched multi junction solar cell has an upper sub-cell, a middle sub-cell and a lower dilute nitride sub-cell, the lower dilute nitride sub-cell having doping in the base and/or the emitter that is at least partially exponentially doped so as to improve its solar cell performance characteristics. In construction, the dilute nitride sub-cell may have the lowest bandgap and be lattice matched to a substrate, the middle cell typically has a higher bandgap than the dilute nitride sub-cell while it is lattice matched to the dilute nitride sub-cell.

Abstract: Multijunction solar cells having at least four subcells are disclosed, in which at least one of the subcells comprises a base layer 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 each of the subcells is substantially lattice matched. Methods of manufacturing solar cells and photovoltaic systems comprising at least one of the multijunction solar cells are also disclosed.

Abstract: Photovoltaic cells with one or more subcells are provided with a wide band gap, pseudomorphic window layer of at least 15 nm in thickness and with an intrinsic material lattice constant that differs by at least 1% from an adjacent emitter layer. This window layer has a higher band gap than a window layer with substantially the same intrinsic material lattice constant as the adjacent emitter layer, which increases the light transmission through the window, thereby increasing the current generation in the solar cell. The quality of being pseudomorphic material preserves a good interface between the window and the emitter, reducing the minority carrier surface recombination velocity. A method is provided for building a wide band gap, pseudomorphic window layer of a photovoltaic cell that has an intrinsic material lattice constant that differs by at least 1% from the adjacent emitter layer.

Abstract: Multijunction solar cells having at least four subcells are disclosed, in which at least one of the subcells comprises a base layer 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 each of the subcells is substantially lattice matched. Methods of manufacturing solar cells and photovoltaic systems comprising at least one of the multijunction solar cells are also disclosed.

Abstract: Multijunction solar cells having at least four subcells are disclosed, in which at least one of the subcells comprises a base layer 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 each of the subcells is substantially lattice matched. Methods of manufacturing solar cells and photovoltaic systems comprising at least one of the multijunction solar cells are also disclosed.

Abstract: Photovoltaic cells with one or more subcells are provided with a wide band gap, pseudomorphic window layer of at least 15 nm in thickness and with an intrinsic material lattice constant that differs by at least 1% from an adjacent emitter layer. This window layer has a higher band gap than a window layer with substantially the same intrinsic material lattice constant as the adjacent emitter layer, which increases the light transmission through the window, thereby increasing the current generation in the solar cell. The quality of being pseudomorphic material preserves a good interface between the window and the emitter, reducing the minority carrier surface recombination velocity. A method is provided for building a wide band gap, pseudomorphic window layer of a photovoltaic cell that has an intrinsic material lattice constant that differs by at least 1% from the adjacent emitter layer.

Abstract: An “n-on-p” type multijunction solar cell structure is disclosed using an n-type substrate for the epitaxial growth of III-V semiconductor material, wherein a “p-on-n” tunnel junction diode is disposed between the substrate and one or more heteroepitaxial layers of III-V semiconductor materials.

Abstract: Tunnel junctions are improved by providing a rare earth-Group V interlayer such as erbium arsenide (ErAs) to yield a mid-gap state-assisted tunnel diode structure. Such tunnel junctions survive thermal energy conditions (time/temperature) in the range required for dilute nitride material integration into III-V multi-junction solar cells.

Abstract: A high efficiency triple-junction solar cell and method of manufacture therefor is provided wherein junctions are formed between different types of III-V semiconductor alloy materials, one alloy of which contains a combination of an effective amount of antimony (Sb) with gallium (Ga), indium (In), nitrogen (N, the nitride component) and arsenic (As) to form the dilute nitride semiconductor layer GaInNAsSb which has particularly favorable characteristics in a solar cell. In particular, the bandgap and lattice matching promote efficient solar energy conversion.