Shin-etsu Chemical Co., Ltd.

Hiroyuki Otsuka

Takenori Watabe

Hiroshi Hashigami

Ryo Mitta

Shintarou Tsukigata

Takashi Murakami

Yoko Endo

Mitsuhito Takahashi

Shozo Shirai

Naoki Ishikawa

Shun Moriyama

Chikara Mori

Toshifumi Matsuoka

Kenji Yamamoto

Toyohiro Ueguri

Norifumi Takahashi

Yoko Matsuo

Ikuo Sakai

Kenji Abe

Hideo Ooiwa

Kazuo Hara

A solar cell includes a light-receiving surface electrode formed on a light-receiving surface, a back surface electrode formed on a backside, and a CZ silicon single crystal substrate doped with gallium. The CZ silicon single crystal substrate contains 12 ppm or more oxygen atoms. A spiral oxygen-induced defect is not observed in an EL (electroluminescence) image of the solar cell.

Method for manufacturing substrate for solar cell and substrate for solar cell

A solar cell having a P-type silicon substrate where one main surface is a light-receiving surface and another is a backside, a plurality of back surface electrodes formed on a part of the backside, an N-type layer in at least a part of the light-receiving surface, and contact areas in which the substrate contacts the electrodes. The P-type silicon substrate is a silicon substrate doped with gallium and has a resistivity of 2.5 Ω·cm or less; and a back surface electrode pitch P[mm] of contact areas in which the P-type silicon substrate is in contact with the back surface electrodes and the resistivity R[Ω·cm] of the substrate satisfy the relation represented by the following formula (1).log()≤−log()+1.0  (1)

Solar cell and solar cell module

A solar cell is provided with: a semiconductor substrate having a light-receiving surface and a non-light-receiving surface; a PN junction section formed on the semiconductor substrate; a passivation layer formed on the light-receiving surface and/or the non-light-receiving surface; and power extraction electrodes formed on the light-receiving surface and the non-light-receiving surface. The solar cell is characterized in that the passivation layer includes an aluminum oxide film having a thickness of 40 nm or less. As a result of forming a aluminum oxide film having a predetermined thickness on the surface of the substrate, it is possible to achieve excellent passivation performance and excellent electrical contact between silicon and the electrode by merely firing the conductive paste, which is conventional technology. Furthermore, an annealing step, which has been necessary to achieve the passivation effects of the aluminum oxide film in the past, can be eliminated, thus dramatically reducing costs.

Solar cell, method for manufacturing solar cell, and solar cell module

Provided is a solar cell that includes: a semiconductor substrate on which at least pn junctions are formed; a multiplicity of finger electrodes that are formed in a comb-like shape on at least one surface of the semiconductor substrate; and a plurality of bus bar electrodes that are arranged so as to be orthogonal to the lengthwise direction of the finger electrodes and are connected with the finger electrodes. This solar cell is configured so that the finger electrodes connected with one of the bus bar electrodes are separated from the finger electrodes connected with another bus bar electrode that is arranged so as to be parallel to this one of the bus bar electrodes, and ends in the lengthwise direction of adjacent two or more of the finger electrodes connected with each bus bar electrode are electrically connected with one another by auxiliary electrodes. With this configuration, while disadvantage due to disconnection is solved, a high fill factor, a high conversion efficiency, and small cell warpage are achieved, whereby the manufacturing yield is improved. Further, this does not involve increases in costs, and high long-term reliability is achieved. Thus, a solar cell module made up of the solar cells maintains high output.

The present invention is a method for manufacturing a substrate for a solar cell composed of a single crystal silicon, including the steps of: producing a silicon single crystal ingot; slicing a silicon substrate from the silicon single crystal ingot; and subjecting the silicon substrate to low temperature thermal treatment at a temperature of 800° C. or more and less than 1200° C., wherein the silicon single crystal ingot or the silicon substrate is subjected to high temperature thermal treatment at a temperature of 1200° C. or more for 30 seconds or more before the low temperature thermal treatment. As a result, it is possible to provide a method for manufacturing a substrate for a solar cell that can prevent decrease in the minority carrier lifetime of the substrate even when the substrate has higher oxygen concentration.

A method for manufacturing a solar cell having a P-type silicon substrate wherein one main surface is a light-receiving surface and another is a backside, a plurality of back surface electrodes formed on a part of the backside, an N-type layer in at least a part of the light-receiving surface, and contact areas in which the substrate contacts the electrodes; wherein the P-type silicon substrate is a silicon substrate doped with gallium and has a resistivity of 2.5 &#x3a9;&#xb7;cm or less; and a back surface electrode pitch P[mm] of contact areas in which the P-type silicon substrate is in contact with the back surface electrodes and the resistivity R[&#x3a9;&#xb7;cm] of the substrate satisfy the relation represented by the following formula (1).log()&#x2264;&#x2212;log()+1.0&#x2003;&#x2003;(1)

Disclosed is a firing furnace for firing an electrode of a solar cell element, which is provided with: a transfer member, which transfers a substrate having a conductive paste applied thereto; a heating section, which heats the substrate and fires the conductive paste; and a cooling section, which cools the heated substrate. The furnace is also provided with a heating means for heating the transfer member. Specifically, at the time of firing the electrode paste using the wire-type firing furnace, since a wire is fired at a temperature substantially equivalent to the ambient temperature of the heating section, deterioration of yield due to having the electrode damaged by a deposited material of the metal component of the conductive paste is suppressed, said deposited material being deposited on the wire, and the wire-type firing furnace can be continuously used.

Firing furnace for firing electrode of solar cell element, method for manufacturing solar cell element, and solar cell element

A solar cell has a P-type silicon substrate in which one main surface is a light-receiving surface and another main surface is a backside, a dielectric film on the backside, and an N-conductivity type layer in at least a part of the light-receiving surface of the P-type silicon substrate, wherein the P-type silicon substrate is a silicon substrate doped with gallium, and the backside of the P-type silicon substrate contains a diffused group III element. This provides a solar cell with excellent conversion efficiency provided with a gallium-doped substrate, and a method for manufacturing the same.

Solar cell and method for manufacturing the same

A solar cell has a P-type silicon substrate in which one main surface is a light-receiving surface and another main surface is a backside, a dielectric film on the backside, and an N-conductivity type layer in at least a part of the light-receiving surface of the P-type silicon substrate. The P-type silicon substrate is a silicon substrate doped with gallium, and the backside of the P-type silicon substrate contains a diffused group III element.

A method for screen printing, including: by using a screen printing apparatus provided with a screen printing plate having an opening part corresponding to a printing pattern, a scraper, and a squeegee, filling a paste supplied on an upper surface of the screen printing plate into the opening part of the screen printing plate by the scraper; and, after that, pushing out the paste to a predetermined position of an object to be printed from the opening part of the screen printing plate by the squeegee to screen-print the paste corresponding to the printing pattern on the object to be printed, wherein the humidity in the screen printing apparatus is adjusted during the screen printing. As a result, by controlling an amount of moisture in the paste on the screen printing plate, a screen printing method is capable of improving the printing property of the paste.

Screen printing apparatus, screen printing method, and electrode formation method of solar battery

A photovoltaic generation system includes: a solar cell array formed with one or more solar cell modules; and a power conditioner, wherein each of the solar cell modules includes one or more solar cells, the photovoltaic generation system further has a first conductive wire connected to a conductor parts which is provided at each of the solar cell modules and which is insulated from the solar cells, and a constant voltage power supply whose one end is connected to the first conductive wire, and a potential is supplied to the conductor parts by the constant voltage power supply. As a result, the photovoltaic generation system which can suppress degradation of solar cell characteristics due to PID while suppressing increase in manufacturing cost of the solar cell module is provided.

Photovoltaic generation system and method for using the same

The present invention is a method for manufacturing an FZ silicon single crystal for a solar cell, including the steps of: pulling a CZ silicon single crystal doped with gallium by a Czochralski method; and float-zone processing a raw material rod, with the raw material rod being the CZ silicon single crystal, at 1.6 atmospheric pressure or more to manufacture the FZ silicon single crystal. As a result, it is possible to provide a method for manufacturing an FZ silicon single crystal for a solar cell that can decrease the amount of gallium dopant evaporated during the float-zone processing, thereby preventing the silicon single crystal from increasing the resistance while decreasing oxygen, which is inevitably introduced into a CZ crystal, and preventing formation of a B-O pair, which causes a problem to the characteristics of a solar cell.

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Annaka, Japan

Hiroyuki Otsuka