Toyota Jidosha Kabushiki Kaisha

Tomonori Nagashima

Kyoichi Tange

Kouetsu Hibino

Kenichi Okumura

Naoki Nakamura

Yasuhiko Takeda

Mitsuaki Tomita

Daniel James Farrell

Takeshi Nishikawa

Takashi Sagae

Yasuji Fukui

Nicholas John Ekins-Daukes

A photoelectric conversion device includes: a wavelength converting region that absorbs ambient light to generate electrons and holes, and recombines the generated electrons and holes to generate monochromatic light; and a photoelectric conversion region that has a p-n junction or p-i-n junction, absorbs the monochromatic light generated in the wavelength converting region to generate electrons and holes, and separates and moves the electrons and holes generated by absorption of the monochromatic light. The wavelength converting region includes: a carrier generating region that generates the electrons and holes; a light emitting region that generates the monochromatic light; and a carrier selective transfer region that is disposed between the carrier generating region and the light emitting region and that, of the electrons and holes generated in the carrier generating region, moves those electrons and holes having specific energies difference there between to the light emitting region.

Photoelectric conversion device

In a back-surface electrode type photoelectric conversion element having electrodes and semiconductor layers for collecting carriers disposed only on a back surface side of a semiconductor substrate, a semiconductor thin film that is larger in band gap than the semiconductor substrate and that contains an element causing a conductivity identical to or different from a conductivity of the semiconductor substrate is provided on a light-receiving surface side of the semiconductor substrate, and a diffusion layer is formed on a surface of the semiconductor substrate. Alternatively, 95% or more of light beams having a wavelength of anywhere from 800 nm to 2000 nm are caused to penetrate the light-receiving surface side of the semiconductor substrate, and an insulative thin film containing an element causing a conductivity identical to or different from the conductivity of the semiconductor substrate is provided so as to form a diffusion layer on the surface of the semiconductor substrate through diffusion of the element.

Photoelectric conversion element and method of manufacturing the same

A nonlinear optical silica material mainly consisting of SiO &mdash;GeO to which hydrogen or halogen element X is added. Oxygen bonded to Ge contained in the nonlinear optical silica material is replaced by H or X, and one Ge has two Ge&mdash;O bonds and one Ge&mdash;H (or Ge&mdash;X) bond at Ge&middot; points where nonlinearity is exhibited in the silica material. The Ge&mdash;H (or Ge&mdash;X) bond does not relate to a crystal network, so that when the polarity is oriented in order to exhibit nonlinearity at Ge&middot;, an electric field to be applied can be lowered, and when a optical semiconductor hybrid element or the like is produced, other portions of the semiconductor elements can be prevented from being broken or degraded in performance. An insulating film can be interposed between the semiconductor substrate and the nonlinear optical silica film to prevent undesired impurities from dispersing into the semiconductor substrate and other elements and preventing a defect from being caused in the crystal of the substrate due to the silica film.

Nonlinear optical silica material and nonlinear optical device

A solar cell that is capable of having a thickness optimum for the highest photoelectric conversion efficiency and achieves reduction of carrier recombination loss is provided. For this purpose, a solar cell (10) is formed by stacking a top cell (12) including an n.sup.+ layer, a p layer, and a p.sup.+ layer, and a bottom cell (14) including an n.sup.+ layer and a p.sup.+ layer arranged at the bottom of the p layer along the back surface. The top cell (12) has a band gap wider than that of the bottom cell (14). A top electrode (18) is formed at the n.sup.+ layer of the top cell (12), while a negative electrode (26) and a positive electrode (28) are individually connected to the n.sup.+ layer and the p.sup.+ layer of the bottom cell (14), respectively. These negative and positive electrodes (26, 28) serve as a pair of electrodes of the bottom cell (14) and the positive electrode (28) is also used as the other electrode of the top cell (12), forming a pair with the top electrode (18) which is one electrode of the top cell (12). As a result, the minority carriers generated in the top and bottom cells (12, 14) can be individually obtained from the electrodes of the respective cells where they are generated.

Tandem solar cell

In order to provide a converging solar module which achieves effective electricity generation, as well as significant reduction of costs and driving energy required to track the sun, a cell stage 20 carrying solar cells 16 is provided opposite to converging lenses 10. Some elastic members are provided between a pair of adjacent side edges of the cell stage 20 and corresponding side walls of a vessel 18. Along the other pair of side edges, stage driving bars 24 are provided. The stage driving bars 24 are moved horizontally by opening/closing operations of feeder valves X1, X2, Y1, Y2 and drain valves X3, X4, Y3, Y4 thereby moving the cell stage 20 horizontally in the direction perpendicular to the direction in which the stage driving bars 24 have moved. With an action of the elastic members 22 and the stage driving bars 24, the position of the cell stage 20 is adjusted such that the solar cells 16 thereon are brought into a position where converged spots 14 are formed.

Converging solar module

To provide a tracking-type solar module capable of high-performance sunlight-tracking with a simple configuration while simultaneously performing highly effective cooling of a solar cell, a solar cell is movably installed within a transparent cooling tube and is connected to a motor with a crank. A position detecting sensor is also installed inside the transparent cooling tube. Sunlight is refracted by a cooling medium filled inside the transparent cooling tube and is converged on the inner surface of the transparent cooling tube. The position detecting sensor detects the position at which sunlight is converged and the sunlight is tracked by the motor moving the solar cell to that position. Simultaneously, the cooling medium inside the transparent cooling tube directly cools the solar cell.

Tracking solar module

The present invention discloses a converging type solar cell element able to restrain recombination of carriers and inflow of carriers into an embankment section and improve photoelectric conversion efficiency. A p.sup.+ diffusion layer 16 is formed on the surface of a sunlight receiving section 10 which is formed on a silicon substrate 12 comprising a p-type silicon. An energy gradient arises between the p.sup.+ diffusion layer 16 and the silicon substrate 12. Therefore, free electrons, which are minority carriers among the carriers generated in the silicon substrate 12 resulting from irradiation of sunlight to the sunlight receiving section 10, can be prevented from migrating to the surface side of the silicon substrate 12. Further, recombination of free electrons which may arise due to lattice defects of the surface can also be prevented. Still further, the p.sup.+ diffusion layer 16 may also be formed on a back surface side of the embankment section 14 which surrounds the sunlight receiving section 10. Due to operation of the aforementioned energy gradient, inflow of the free electrons, which are minority carriers, into the embankment section can be prevented.

Converging type solar cell element

For a converging solar cell element capable of preventing excessive concentration of converged sunlight to one point without lowering the degree of light convergence, a p+ layer 14 and an n+ layer 12 are formed on the rear surface of a silicon substrate; a positive pole 16 and a negative pole 18 are formed in response to the respective layers; and, on the front surface side, a light receiving surface 24 is formed with a bank portion 28 which enhances intensity in the surrounding area. In the central portion of the light receiving surface 24, a projected portion 26 is formed, which scatters converged sunlight and prevents the concentration of converged sunlight to one point.

Converging solar cell element

In order to generate sufficient electricity in a small light converging solar module, a power generation solar cell is provided with four movement solar cells, situated around it. Below the respective movement solar cells, electromagnets are situated, connected to corresponding movement solar cells. The power generation solar cell, the movement solar cells, and the electromagnets are all mounted on a cell holder, around which a permanent magnet in the form of a ring is provided. When a converged spot moves its position from on the power generation solar cell to a position off the power generation solar cell, and onto one of the movement solar cells, electricity is supplied to the corresponding electromagnet, thereby moving the cell holder due to attracting forces generated between the electromagnet and the permanent magnet. After the cell holder is moved to such a point where the converged spot correctly falls on the power generation solar cell, the cell holder stops its movement.

Growing community of inventors

Susono, Japan

Tomonori Nagashima