Other

William J Todorof

Mark A Murphy

The sealed enclosure for an electrical power generation solar concentrator holds and protects the photovoltaic cell from ambient conditions and thermal shock, while multiple fingers of front and rear electrical contact terminals accommodate thermal expansion and contraction of the cell and minimize mechanical stresses on the cell. This sealed enclosure also holds the secondary lens and protects the internally reflective truncated conical rear surface of the lens. A base member has a socket for receiving the cell and its associated front and rear terminal members together with an insulator alignment disc having an opening receiving the cell and for aligning the cell with the axis of the concentrator. A front housing removably screws onto the base member with an inturned front lip gripping a peripheral flange on the secondary lens, thereby aligning it with the cell and firmly pressing it against the cell front for causing thermal mass and inertial of the lens to moderate temperature changes in the cell. The base member screws onto a pedestal of a finned heat sink of good thermal conductivity fitting into a pre-punched hole in a panel of the concentrator, thus aligning the sealed enclosure with the concentrator axis. The pressure of the secondary lens on the cell causes the cell back to press onto its multiple-fingered rear contact member of good electrical and thermal conductivity which in turn is pressing against a thin electrical insulator in good thermal conductivity with the heat sink pedestal.

Liquid-cooled sealed enclosure for concentrator solar cell and secondary

The flexible photovoltaic cell includes thin front and rear junction regions electrically in series, each formed of ceramic metallic glass semi-conductor alloys of silicon of approximately zero thermal expansion/contraction coefficient laminated with an intervening semi-conducting layer less than 60 Angstroms thick or an insulating layer less than 20 Angstroms thick. The respective spectral sensitivities of the front and rear junction regions are tailored to different frequency ranges. In front are six layers described in sequence rear to front. The lowermost (sixth) is a green/blue semi-insulating cobalt and tin passivating and filter layer less than 10 Angstroms thick. The fifth is a semi-conductive, degradation-protective 'window' and one-way mirror for returning back-reflected light. The fourth is an insulating tunneling layer less than 15 Angstroms thick for coupling a front collection grid to the 'window'. Covering the fourth is a triple-layer, anti-reflection coating (ARC) whose middle layer bonds the outer ARC layers and secondarily protects the cell from atmospheric degradation. An internally reflective rear ARC layer cooperates with the 'window' for returning back-reflected light. The frontmost ARC layer is mainly comprised of Al.sub.2 O.sub.3 /SiO.sub.2 in the range of 200 to 650 Angstroms thickness. The cell backside is shown having undulations for randomizing reflected light rays. The six front layers effectively adapt the cell for receptivity to solar radiation from about 4,000 to about 12,000 Angstroms, excluding radiation outside thereof, thus accepting 68 percent of solar energy vertically reaching the earth's surface.

Multi-layer thin film, flexible silicon alloy photovoltaic cell

Method and apparatus for producing multi-layer, thin-film flexible photovoltaic cells with front and rear junction regions electrically in series and formed of ceramic glass semi-conductor alloys of silicon laminated with an intervening semi-conducting layer less than 60 Angstroms thick or an insulating layer less than 20 Angstroms thick. The respective spectral sensitivities of front and rear junction regions are in different frequency ranges. The method and apparatus include providing two ribbons of the silicon alloy in a molten state, passing the molten ribbons between respective first pairs of opposed rollers in first rolling stations, cooling the first pairs of rollers for rapidly cooling the molten ribbons to semi-solidus condition, then passing them between other pairs of opposed rollers in other rolling stations at a ribbon temperature in the range from 740.degree. C. to 1130.degree. C. for promoting crystal growth in the ribbons while being rolled. The two ribbons are laminated together and then suddenly quenched for stopping further crystal growth. The ribbons are shown initially formed by extruding. They are kept 20.degree. C. to 60.degree. C. below the semi-liqudus condition of the silicon alloy. The quenching occurs in a liquid etchant bath. Doping of the ribbons and ion implantation are carried out before laminating them together.

Method for producing multi-layer, thin-film, flexible silicon alloy

The flexible photovoltaic cell includes thin front and rear junction regions electrically in series each formed of ceramic metallic glass semi-conductor alloys of silicon of approximately zero thermal expansion/contraction coefficient laminated with an intervening semi-conducting layer less than 60 Angstroms thick or an insulating layer less than 20 Angstroms thick. The respective spectral sensitivities of front and rear junction regions are tailored to different frequency ranges. In front are six layers described in sequence rear to front. The lowermost (sixth) is a green/blue semi-insulating cobalt and tin passivating and filter layer less than 10 Angstroms thick. The fifth is a semi-conductive, degradation-protective 'window' and one-way mirror for returning back-reflected light. The fourth is an insulating tunneling layer less than 15 Angstroms thick for coupling a front collection grid to the 'window'. Covering the fourth layer is a triple-layer, anti-reflection coating (ARC) whose middle layer bonds the outer ARC layers and secondarily protects the cell from atmospheric degradation. An internally refelective rear ARC layer cooperates with the 'window' for returning back-reflected light. The frontmost ARC layer is mainly comprised of Al.sub.2 O.sub.3 /S.sub.i O.sub.2 in the range of 200 to 650 Angstroms thickness. The cell backside is shown having undulations for randomizing reflected light rays. The six front layers effectively adapt the cell for receptivity to solar radiation from about 4,000 to about 12,000 Angstroms, excluding radiation outside thereof, thus accepting 68 percent of solar energy vertically reaching the earth's surface.

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Laguna Beach, CA, United States of America

William J Todorof