Solar Junction Corporation

Michael West Wiemer

Onur Fidaner

Homan Bernard Yuen

Michael J Sheldon

Vijit A Sabnis

Rebecca Elizabeth Jones-Albertus

Ewelina Natalia Lucow

Ting Liu

Pranob Misra

Daniel Derkacs

Ferran Suarez

Paul F Lamarche

Lan Zhang

Ferran Suarez Arias

Ferran Suarez-Arias

A single-step wet etch process is provided to isolate multijunction solar cells on semiconductor substrates, wherein the wet etch chemistry removes semiconductor materials nonselectively without a major difference in etch rate between different heteroepitaxial layers. The solar cells thus formed comprise multiple heterogeneous semiconductor layers epitaxially grown on the semiconductor substrate.

Method for etching multi-layer epitaxial material

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

The present disclosure provides multi-junction solar cell structures and fabrication methods thereof that improve electrical testing capability and reduce chip failure rates. In the present invention a special masking pattern is used in the layout such that all or some of the epitaxial layers are etched away in the corner areas of each solar cell. Consequently, the semiconductor substrate or one or more of the interconnections between junctions become accessible from the top (the side facing the sun) to make electrical connections.

Methods and apparatus for identifying and reducing semiconductor failures

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 semiconductor light detection device fabrication technique is provided in which the cap etch and anti-reflection coating steps are performed in a single, self-aligned lithography module.

Method for making semiconductor light detection devices

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.

Growing community of inventors

Campbell, CA, United States of America

Michael West Wiemer