Chevron Research Company

Daidosanso K. K.

John A Cape

Paul Stephen McLeod

Lewis M Fraas

Larry D Partain

A vacuum chemical epitaxy apparatus comprising a first mixing chamber having an inlet for introducing a metal-organic gaseous materials and n-type and p-type dopants, and a plurality of outlets for directing the flow of said metal-organic gases and n-type and p-type dopants toward a substrate; a second mixing chamber disposed below said first chamber having an inlet for introducing a metal-organic gaseous material and n-type and p-type dopants, and a plurality of passages through said first chamber and an outlet for each passage, wherein the passage outlets are in substantially the same plane with the outlets of the first chamber; and means for exhausting the metal-organic gaseous materials and n-type and p-type dopants from the second chamber.

Apparatus and process for vacuum chemical epitaxy

An injection block having a plurality of geometrically arranged injection sources for gaseous Group III metal organic compounds is oriented substantially perpendicular to the placement of at least one semiconductor wafer substrate within a vacuum reaction chamber. The injector sources are sized to provide disbursing flow of the compounds capable of depositing a layer of about 5% uniform thickness or less over substantially the entire semiconductor wafer. An injection source of Group V compounds is located centrally within the geometrically arranged injection sources for the Group III compounds. The Group V injection source is sized to supply an excess of the Group V compounds required to react with the Group III compounds in order to form Group III-V semiconductor layers on the substrate and partition the Group III sources into groups having substantially equal numbers of injection sources. An excess of Group V comounds is injected. The vacuum within the reaction chamber is adjusted at predetermined flow rates of the Group III compounds such that a mean-free path of the Group III compounds is greater than the distance from the injection source of the Group III compounds to the substrate. The substrate is heated to a temperature to which a reaction proceeds. The unreacted Group III compounds are exhausted from the vacuum chamber adjacent the edges of a substrate holder facing the top of the chamber opposite to the injection sources. In this manner, the disbursing flow of Group III compounds from the geometric arrangement of sources uniformly overlaps substantially the entire substrate and the algebraic sum of the fluxes from the Group III compound sources remains constant across the area of the substrate upon which the layer is to be deposited.

Process for vacuum chemical epitaxy

The present invention is an apparatus of mechanically stacked photovoltaic cells having two cells. The bottom cell has a layer of GaSb having regions of different conductivity forming a homojunction therein. The GaSb layer is sandwiched between a conductive substrate and a bottom passivating layer. In the bottom cell is a means for forming electrical contacts to the substrate and the incident surface of the bottom passivating layer. The top cell has a layer of GaAs having regions of different conductivity forming a homojunction therein, a top passivating layer contacting the surface of the layer of GaAs which is incident to solar radiation, and a means for forming electrical contacts to the layer of GaAs opposed to solar radiation and the incident surface of the passivating layer.

GaAs on GaSb mechanically stacked photovoltaic cells, package assembly,

The present invention is an apparatus of mechanically stacked photovoltaic cells having a bottom heat spreader and a top heat spreader, a bottom photovoltaic cell and a top photovoltaic cell, and means for forming the necessary electrical contacts. The heat spreaders are electrically insulated from each other but are thermally connected to each other. The bottom photovoltaic cell has an anode and a cathode and is thermally bonded to the bottom heat spreader and is thermally connected to the top heat spreader. The top photovoltaic cell has an anode and a cathode, is electrically insulated from the bottom photovoltaic cell, and is thermally bonded to the top heat spreader and is thermally connected to the bottom heat spreader. The means for forming the necessary electrical contacts includes a means for electrically contacting the anode of the bottom photovoltaic cell, a means for electrically contacting the cathode of the bottom photovoltaic cell, a means for electrically contacting the anode of the top photovoltaic cell, and a means for electrically contacting the cathode of the top photovoltaic cell.

Mechanically stacked photovoltaic cells, package assembly, and modules

A mechanically stacked module package is described. The package permits the effective mechanical stacking of two solar cells in a compact arrangement. The design also permits the easy wiring of the package into a voltage matching configuration for module wiring thus eliminating the problems of current matching the top and bottom cells. The package design can be used with any mechanically stacked cells although the design is most suitable for concentrator solar cell configurations where the removal of heat to avoid degradation and shortening of lifetime is a major concern.

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San Rafael, CA, United States of America

John A Cape