MTPV Power Corporation | Date: 2012-11-30
An improved submicron gap thermophotovoltaic structure and method comprising an emitter substrate with a first surface for receiving heat energy and a second surface for emitting infrared radiation across an evacuated submicron gap to a juxtaposed first surface of an infrared radiation-transparent window substrate having a high refractive index. A second surface of the infrared radiation-transparent substrate opposite the first surface is affixed to a photovoltaic cell substrate by an infrared-transparent compliant adhesive layer. Relying on the high refractive index of the infrared radiation-transparent window substrate, the low refractive index of the submicron gap and Snells law, the infrared radiation received by the first surface of the infrared radiation-transparent window substrate is focused onto a more perpendicular path to the surface of the photovoltaic cell substrate. This results in increased electrical power output and improved efficiency by the thermophotovoltaic structure.
MTPV Power Corporation | Date: 2014-03-14
The present invention relates to multi-cell devices fabricated on a common substrate that are more desirable than single cell devices, particularly in photovoltaic applications. Multi-cell devices operate with lower currents, higher output voltages, and lower internal power losses. Prior art multi-cell devices use physical isolation to achieve electrical isolation between cells. In order to fabricate a multicell device on a common substrate, the individual cells must be electrically isolated from one another. In the prior art, isolation generally required creating a physical dielectric barrier between the cells, which adds complexity and cost to the fabrication process. The disclosed invention achieves electrical isolation without physical isolation by proper orientation of interdigitated junctions such that the diffusion fields present in the interdigitated region essentially prevent the formation of a significant parasitic current which would be in opposition to the output of the device.
Mtpv Power Corporation | Date: 2014-03-14
A method and device for maintaining a low temperature of a cold-side emitter for improving the efficiency of a sub-micron gap thermophotovoltaic cell structure. A thermophotovoltaic cell structure may comprise multiple layers compressed together by a force mechanism so that the sub-micron gap dimension is relatively constant although the layer boundaries may not be substantially flat compared to the relatively constant sub-micron dimension. The layered structure includes a hot side thermal emitter having a surface separated from a photovoltaic cell surface by a sub-micron gap having a dimension maintained by spacers. The surface of the photovoltaic cell opposite the sub-micron gap is compressibly positioned against a surface of microchannel heat sink and the surface of the microchannel heat sink opposite the photovoltaic cell is compressibly positioned against a flat metal plate layer and a compressible layer.
MTPV Power Corporation | Date: 2014-01-20
An MTPV thermophotovoltaic chip comprising a photovoltaic cell substrate, micron/sub-micron gap-spaced from a juxtaposed heat or infrared radiation-emitting substrate, with a radiation-transparent intermediate window substrate preferably compliantly adhered to the photovoltaic cell substrate and bounding the gap space therewith.
Borrego J.M.,MTPV Power Corporation |
Brown E.,MTPV Power Corporation |
Greiff P.,MTPV Power Corporation |
Huffaker D.L.,University of California at Los Angeles |
And 3 more authors.
Journal of Renewable and Sustainable Energy | Year: 2014
This paper presents the device design, modeling, materials growth, and device fabrication results of wafer scale monolithically integrated modules (MIMs) of series interconnected GaSb thermo-photovoltaic (TPV) cells grown on 50 mm diameter semi-insulating (SI) GaAs substrates. The feasibility of using GaSb epi-layers grown on SI GaAs for fabricating modules of photovoltaic (PV) cells connected in series for the conversion of low temperature heat radiating sources into electrical energy has been demonstrated. Device modeling shows that assuming an Shockley-Read-Hall recombination lifetime of 100 ns, in addition to intrinsic radiative and Auger recombination in GaSb, it is possible to design PV cells that when placed at sub-micron distance from a 900 °C radiating source are able to convert the heat into electrical energy at a power density of 1.5 to 3 W/cm2 using GaSb epi-layers grown on SI GaAs. The advantage of using SI GaAs is that it is possible to produce MIM modules of PV cells that can have output voltages of 6 V to 10 V decreasing the internal resistance of the PV cell. The device design and fabrication process presented here can be used for large area device arrays high efficiency solar photovoltaic cells employing other semiconductor materials for terrestrial and space applications with back-side illumination architecture. © 2013 AIP Publishing LLC. Source