Solar Junction Corporation

Array Photonics, Inc.

Homan Bernard Yuen

Ting Liu

Pranob Misra

Rebecca Elizabeth Jones-Albertus

Michael J Sheldon

Michael West Wiemer

Ferran Suarez

Vijit A Sabnis

Rebecca Elizabeth Jones

Ilya Fushman

Daniel Derkacs

Onur Fidaner

Jordan Lang

Arsen Sukiasyan

David Taner Bilir

Ferran Suarez Arias

Ferran Suarez-Arias

Micahel West Wiemer

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.

High efficiency multijunction photovoltaic cells

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.

Multi-junction solar cell with dilute nitride sub-cell having graded doping

An alloy composition for a subcell of a solar cell is provided that has a bandgap of at least 0.9 eV, namely, GaInNAsSbwith a low antimony (Sb) content and with enhanced indium (In) content and enhanced nitrogen (N) content, achieving substantial lattice matching to GaAs and Ge substrates and providing both high short circuit currents and high open circuit voltages in GaInNAsSb subcells for multijunction solar cells. The composition ranges for GaInNAsSbare 0.07&#x2264;x&#x2264;0.18, 0.025&#x2264;y&#x2264;0.04 and 0.001&#x2264;z&#x2264;0.03.

Lattice matchable alloy for solar cells

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.

Non-alloyed contacts for III-V based solar cells

An alloy composition for a subcell of a solar cell is provided that has a bandgap of at least 0.9 eV, namely, GaInNAsSbwith a low antimony (Sb) content and with enhanced indium (In) content and enhanced nitrogen (N) content, achieving substantial lattice matching to GaAs and Ge substrates and providing both high short circuit currents and high open circuit voltages in GaInNAsSb subcells for multijunction solar cells. The composition ranges for GaInNAsSbare 0.07&#x2266;x&#x2266;0.18, 0.025&#x2266;y&#x2266;0.04 and 0.001&#x2266;z&#x2266;0.03.

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. The upper sub-cell typically has the highest bandgap and is lattice matched to the adjacent sub-cell. In further embodiments, a multi junction solar cell according to the invention may comprise four, five or more sub-cells in which the one or more sub-cells may each comprise exponentially doped dilute nitride alloys.

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.

High efficiency multijunction solar cells

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.

Pseudomorphic window layer for multijunction solar cells

A multilayer window structure for a solar cell comprises one or more layers where the bottom layer has an intrinsic material lattice spacing that is substantially the same as the emitter in the plane perpendicular to the direction of epitaxial growth. One or more upper layers of the window structure has progressively higher band gaps than the bottom layer and has intrinsic material lattice spacing is substantially different than the emitter intrinsic material lattice spacing.

Window structure for solar cell

An alloy composition for a subcell of a solar cell is provided that has a bandgap of at least 0.9 eV, namely, GaInNAsSbwith a low antimony (Sb) content and with enhanced indium (In) content, and enhanced nitrogen (N) content, achieving substantial lattice matching to GaAs and Ge substrates and providing both high short circuit currents and high open circuit voltages in GaInNAsSb subcells for multijunction solar cells. The composition ranges for GaInNAsSbare 0.07&#x2266;x&#x2266;0.18, 0.025&#x2266;y&#x2266;0.04 and 0.001&#x2266;z&#x2266;0.03.

Growing community of inventors

Santa Clara, CA, United States of America

Homan Bernard Yuen