Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Shoichi Karakida

Motoharu Miyashita

Hiroaki Morikawa

Yutaka Mihashi

Hirotaka Kizuki

Mitsunori Nakatani

Takahiko Nishida

Takashi Nishimura

Yuji Ohkura

Yasutomo Kajikawa

Junji Kobayashi

Tatsuya Kimura

Norio Hayafuji

Takashi Motoda

Yasuaki Yoshida

Akihiro Shima

Nobuaki Kaneno

Shigeki Kageyama

Takafumi Kawasaki

Takahiro Kawasaki

Diethard Marx

Yusuke Oshiro

Mitsuhiro Nonogaki

Hajime Tsugeno

A method for manufacturing a solar-power-generator substrate by cutting out a semiconductor substrate by slicing a semiconductor ingot and then by forming a texture structure on a surface of the semiconductor substrate by performing a surface treatment on the surface of the semiconductor substrate, includes: cleaning including cleaning and removing an organic impurity and a metal impurity adhering to the surface of the semiconductor substrate with a cleaning fluid containing an oxidizing chemical; and etching including removing a damaged layer on a substrate surface generated by the slicing and forming the texture structure on the surface of the semiconductor substrate by performing anisotropic etching on the surface of the semiconductor substrate with an alkaline aqueous solution, the etching being performed subsequent to the cleaning.

Method for manufacturing solar-power-generator substrate and apparatus for manufacturing solar-power-generator substrate

The invention includes: a first process of forming a texture structure on both surfaces of a semiconductor substrate of a first conductivity type; a second process of measuring a reflectance distribution of the both surfaces of the semiconductor substrate on which the texture structure is formed; a third process of forming an impurity diffusion layer, in which an impurity element of a second conductivity type is diffused, on one of the both surfaces of the semiconductor substrate which is narrower in the reflectance distribution; a fourth process of forming, on the impurity diffusion layer, a light receiving surface-side electrode having a predetermined pattern and electrically connected to the impurity diffusion layer; and a fifth process of forming a back surface-side electrode on another of the both surfaces of the semiconductor substrate which is wider in the reflectance distribution.

Manufacturing method for solar cell and solar cell manufacturing system

Included are a semiconductor substrate including, on one surface side, a dopant diffusion layer, a light-receiving surface side electrode electrically connected to the dopant diffusion layer and formed on the one surface side of the semiconductor substrate, and a rear surface side electrode formed on the other surface side of the semiconductor substrate. A first unevenness structure including first projected sections each having a square pyramid shape in a light-receiving surface side electrode formation region in which the light-receiving surface side electrode is formed on the one surface side of the semiconductor substrate including the dopant diffusion layer. A second unevenness structure including second projected sections each having a square pyramid shape larger than the first projected sections in a region where the light-receiving surface side electrode is not formed on the one surface side of the semiconductor substrate including the dopant diffusion layer.

Solar battery cell and method of manufacturing the solar battery cell

A manufacturing method of a solar cell in which a light receiving side electrode including grid electrodes is provided on one side of a semiconductor substrate, comprises: a first step of forming an impurity diffusion layer on one side of the semiconductor substrate of a first conductivity type, the diffusion layer having a second conductivity-type impurity diffused therein; a second step of measuring a sheet resistance value of the diffusion layer at a plurality of measurement points in a surface of the diffusion layer; and a third step of dividing the surface of the diffusion layer into a plurality of areas corresponding to the measured sheet resistance values of the surface of the diffusion layer, setting a distance between adjacent grid electrodes for each of the areas, and forming the light receiving side electrode, which is electrically connected to the diffusion layer, on the diffusion layer.

Solar cell and manufacturing method thereof

When forming an electrode by printing several times, the cross section area of the electrode is increased and the resistance is reduced while more electrode material is required, which leads to a cost up and waste of resources. There is provided a solar cell manufacturing method for forming an electrode of a predetermined pattern by repeating printing on a substrate surface by a predetermined number of times. A mask pattern for printing the entire predetermined pattern is used at least once among the predetermined number of printings while mask patterns, each for printing a part of the predetermined pattern, are used in the other printings, thereby forming the electrode of the predetermined pattern.

Solar battery and manufacturing method therefor

A solar cell comprises a substrate that includes a photoelectric conversion function, a first electrode provided on one surface of the substrate, a second electrode provided on other surface of the substrate, and a third electrode provided on the other surface of the substrate with its periphery overlapping the second electrode in the in-plane direction of the substrate for extracting an electric power from the second electrode. The thickness of the second electrode is larger than that of the third electrode, and the difference between the thickness of the second electrode and that of the third electrode is within a range from equal to or more than 10 micrometers to equal to or less than 30 micrometers. Thereby, in the solar cell, an electrode separation (alloy separation) can be effectively prevented.

A solar cell includes a photoelectric conversion layer, a first electrode on one surface of the photoelectric conversion layer, a second electrode provided on other surface of the photoelectric conversion layer, and a third electrode on the other surface of the photoelectric conversion layer. The third electrode is substantially rectangular with its corners rounded off in the in-plane direction of the photoelectric conversion layer, and overlaps the second electrode at the periphery thereof.

Solar cell

A solar cell includes a photoelectric conversion substrate, a first electrode on one surface of the substrate, a second electrode on the other surface of the substrate, and a third electrode on the other surface of the substrate. The third electrode extracts electric power from the second electrode, and overlaps the second electrode at the periphery in the in-plane direction of the photoelectric conversion substrate. The thickness of the second electrode is larger than that of the third electrode, and the difference between the thickness of the second electrode and that of the third electrode is not less than 10 micrometers and not more than 30 micrometers.

A method of producing silicon blocks by cutting a silicon ingot is provided. The method uses a silicon ingot cutting slurry containing abrasive grains and an alkaline substance so as to provide the silicon blocks that can be produced into silicon wafers each having a thin thickness with reduced substrate damage at the time of producing a solar battery. The alkaline substance has a content mass that is at least 3.5% with respect to the mass of the entire liquid components of said slurry, and the slurry contains an organic amine having a mass ratio of 0.5 to 5.0 with respect to water in the liquid components of the slurry. The slurry is used at a pH of 12 or more and at a temperature of from 65 to 95 degrees C.

Method of producing silicon blocks and silicon wafers

A semiconductor laser includes a first conductivity type GaAs substrate; a AlGaAs double heterojunction structure disposed on the GaAs substrate and including an upper cladding layer having a mesa ridge stripe with a side surface that makes an angle larger than 90.degree. with a front surface of the upper cladding layer; a first current blocking layer of first conductivity type AlGaAs; and a second current blocking layer of first conductivity type AlGaAs, the first and second current blocking layers covering the mesa ridge stripe. The Al compositions of the first and second current blocking layers are larger than that of the upper cladding layer, maintaining an equivalent refractive index of an active region higher than that of other portions of the semiconductor laser. As a result, the differences between the lattice constant of the second current blocking layer and the GaAs substrate or the AlGaAs upper cladding layer are smaller than in prior art semiconductor lasers. Since the second current blocking layer is in the vicinity of the active region in the mesa ridge stripe, stress applied to the active region is reduced, thereby producing a semiconductor laser that facilitates ridge width control and burying layer growth, and with improved reliability.

Semiconductor laser

A pulsation laser includes an n-type AlGaAs cladding layer on an n-type GaAs substrate, three quantum well active layers having central increased thickness regions and disposed on the cladding layer, and a p-type AlGaAs cladding layer disposed on the quantum well active layer. The increased thickness region of the active layer is not more than one-quarter of the length of the resonator of the laser.

Pulsation laser having an active region with a thicker central region in

A method of fabricating a semiconductor laser device includes successively forming an active layer and upper cladding layers on a lower cladding layer, etching and removing portions except regions of the upper cladding layers where a current is to flow to form a stripe-shaped ridge structure, and forming a buffer layer comprising Al.sub.x Ga.sub.1-x As having an Al composition ratio x of 0 to 0.3 on a surface of the upper cladding layers exposed by the etching and forming a current blocking layer of first conductivity type Al.sub.y Ga.sub.1-y As having an Al composition ratio y of at least 0.5 on the buffer layer to bury portions of the upper cladding layers which are not removed by the etching process. Therefore, since the layer grown on the upper cladding layer exposed by etching of AlGaAs or GaAs having a low Al composition ratio (0-0.3), three-dimensional growth of and crystalline defects in the buffer layer are suppressed. Current leakage is suppressed, so that a semiconductor laser device having a low threshold current and a high efficiency is fabricated with a stable yield.

Semiconductor laser device and method of fabricating semiconductor laser

A semiconductor laser includes a ridge structure includes a cladding layer having a thermal expansion coefficient. Current blocking structures are disposed at both sides of the ridge structure and include Al.sub.x Ga.sub.1-x As first current blocking layers having an Al composition x larger than 0.7 and contacting the ridge structure. In this structure, even when the Al composition of the first current blocking layers is reduced at both sides of the ridge structure, the wavelength of light absorbed by the first current blocking layers does not exceed the wavelength of laser light produced in the active layer. Therefore, unwanted absorption of the laser light at both sides of the ridge structure is avoided, resulting in a semiconductor laser with improved laser characteristics.

A semiconductor laser device includes a semiconductor substrate of a first conductivity type; opposed light emitting facets; a double heterojunction structure disposed on the semiconductor substrate and including an optical waveguide that extends between the facets and comprises a light emitting region and a lens region, the lens region being between the light emitting region and one of the facets, the double heterojunction structure including a plurality of AlGaAs series compound semiconductor layers which are thicker in the light emitting region than in the lens region; and a current blocking structure disposed on both sides of the double heterojunction structure and including a lower AlGaAs series compound semiconductor layer of the first conductivity type, an intermediate AlGaAs series compound semiconductor layer of a second conductivity type, opposite the first conductivity type, and an upper AlGaAs series compound semiconductor layer of the first conductivity type. Therefore, a reactive current that does not contribute to laser oscillation is prevented from flowing through the current blocking structure.

Growing community of inventors

Tokyo, Japan

Shoichi Karakida