Solar Junction Corporation

Pranob Misra

Ting Liu

Homan Bernard Yuen

Rebecca Elizabeth Jones-Albertus

Michael J Sheldon

Vijit A Sabnis

Rebecca Elizabeth Jones

Ilya Fushman

Ferran Suarez

Michael West Wiemer

Daniel Derkacs

Onur Fidaner

Micahel West Wiemer

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

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

Pranob Misra