Kaneka Corporation

Masashi Yoshimi

Kenji Yamamoto

Yoshifumi Okamoto

Toshiaki Sasaki

Toshihiko Uto

Mitsuru Ichikawa

Yuko Tawada

Akihiko Nakajima

Toru Sawada

Takashi Suezaki

Yohei Koi

Takayuki Suzuki

Masahiro Goto

Takafumi Fujihara

In manufacturing a crystalline silicon-based solar cell having an intrinsic silicon-based thin film and a conductive silicon-based thin film in this order on a conductive single-crystalline silicon substrate, plasma treatment is performed after the intrinsic silicon-based thin film is formed on the conductive single-crystalline silicon substrate. In the plasma treatment, a surface of the intrinsic silicon-based thin film is exposed to hydrogen plasma while a hydrogen gas and silicon-containing gases are being introduced into a CVD chamber. The amount of the hydrogen introduced into the CVD chamber during the plasma treatment is 150 to 2500 times the introduction amount of the silicon-containing gases.

Method for manufacturing photoelectric conversion device

A crystalline-based silicon photoelectric conversion device comprises: an intrinsic silicon-based layer and a silicon-based layer of a first conductivity type, on one surface of a single-crystal silicon substrate of the first conductivity type; and an intrinsic silicon-based and a silicon-based layer of an opposite conductivity type, in this order on the other surface of the silicon substrate. At least one of forming the intrinsic silicon-based layer of the first conductivity type layer-side forming the intrinsic silicon-based layer of the opposite conductivity type layer-side includes: forming a first intrinsic silicon-based thin-film layer having a thickness of 1-10 nm on the silicon substrate; plasma-treating the silicon substrate in a gas containing mainly hydrogen; and forming a second intrinsic silicon-based thin-film layer on the first intrinsic silicon-based thin-film.

According to the present invention, sufficient light trapping effect can be exhibited and series resistance can be kept small, by sequentially forming a silicon based low refractive index layer and a thin silicon based interface layer on a backside of a photoelectric conversion layer observed from a light incident side, and as a result a silicon based thin film solar cell may be provided efficiently and at low cost.

Silicon based thin film solar cell

A thin film photoelectric converter, especially an integrated thin film photoelectric converter having improved photoelectric conversion efficiency is provided by controlling an open-circuit voltage and a fill factor so as not be small in a thin film photoelectric converter including a crystalline silicon photoelectric conversion unit. The thin film photoelectric converter by the present invention has at least a transparent electrode film, a crystalline silicon photoelectric conversion unit, and a back electrode film formed sequentially on one principal surface of a transparent substrate, and the converter has a whitish discoloring area on a part of a surface of the converter after formation of the crystalline silicon photoelectric conversion unit. A percentage of dimensions of the whitish discoloring area preferably is not more than 5% of a dimension of the photoelectric conversion area. A thin film photoelectric converter of the present invention is preferably an integrated thin film photoelectric converter.

Thin-film photoelectric converter

In a stacked-layer type photoelectric conversion device, a plurality of photoelectric conversion units are stacked on a substrate, each of which includes a one conductivity-type layer, a photoelectric conversion layer of substantially intrinsic semiconductor and an opposite conductivity-type layer in this order from a light-incident side. At least one of the opposite conductivity-type layer in a front photoelectric conversion unit arranged relatively closer to the light-incident side and the one conductivity-type layer in a back photoelectric conversion unit arranged adjacent to the front photoelectric conversion unit includes a silicon composite layer at least in a part thereof. The silicon composite layer has a thickness of more than 20 nm and less than 130 nm and an oxygen concentration of more than 25 atomic % and less than 60 atomic %, and includes silicon-rich phase parts in an amorphous alloy phase of silicon and oxygen.

Stacked photoelectric converter

A method of manufacturing a tandem-type thin film photoelectric conversion device includes the steps of forming at least one photoelectric conversion unit () on a substrate () in a deposition apparatus, taking out the substrate () having the photoelectric conversion unit () from the deposition apparatus to the air, introducing the substrate () into a deposition apparatus and carrying out plasma exposure processing on the substrate () in an atmosphere of a gas mixture containing an impurity for determining the conductivity type of the same conductivity type as that of the uppermost conductivity type layer () and hydrogen, forming a conductivity type intermediate layer () by additionally supplying semiconductor raw gas to the deposition apparatus, and then forming a subsequent photoelectric conversion unit ().

Method for fabricating tandem thin film photoelectric converter

A semiconductor thin film which is deposited by using a chemical vapor deposition method at an underlying layer temperature of 400&deg; C. or less, and contains, as main component elements, a Group IV atom and hydrogen atom. A temperature dependency of an amount of release of hydrogen atoms within the film when the film is heated from room temperature exhibits a profile having a peak of the hydrogen releasing amount at 370&deg; C. or higher and 410&deg; C. or less, and a half-value width of the peak is 30&deg; C. or less.

Semiconductor thin film and thin film device

A method of manufacturing a tandem thin-film solar cell is provided, the solar cell including a plurality of photoelectric conversion units stacked on a substrate, the photoelectric conversion units each having a p-type layer, an i-type photoelectric conversion layer and an n-type layer deposited in this order from a light-incident side of the solar cell, and at least a rear unit among the photoelectric conversion units that is furthest from the light-incident side being a crystalline unit including a crystalline i-type photoelectric conversion layer. The manufacturing method includes the steps of forming at least one of the units on the substrate by plasma CVD and immediately thereafter forming an i-type boundary layer to a thickness of at most 5 nm by plasma CVD, and thereafter removing the substrate into the atmosphere to expose a surface of the i-type boundary layer to the atmosphere and then forming a crystalline unit on the i-type boundary layer by plasma CVD.

Method of manufacturing tandem thin-film solar cell

A silicon-based thin film photoelectric conversion device includes a substrate , a back electrode having a light reflecting metal film , at least one silicon-based photoelectric conversion unit and a front transparent electrode , wherein at least one of the light reflecting metal film and the front transparent electrode has that surface thereof closer to the silicon-based photoelectric conversion unit provided with convexities and concavities having a level difference therebetween in a range of 0.01 to 2 &mgr;m and a pitch greater than the level difference and no more than 25 times the level difference.

Silicon-based thin-film photoelectric device

In a method of manufacturing a silicon-based thin film photoelectric converter, a crystalline photoelectric conversion layer included in the photoelectric converter is deposited by plasma CVD under the following conditions: the temperature of the underlying film is at most 550&deg; C.; a gas introduced into a plasma reaction chamber has a silane-based gas and a hydrogen gas where the flow rate of the hydrogen gas relative to the silane-based gas is at least 50 times; the pressure in the plasma reaction chamber is set to 3 Torr; and the deposition speed is 17 nm/min in the thickness-wise direction.

Method of producing silicon thin-film photoelectric transducer and plasma CVD apparatus used for the method

At least one of a p type semiconductor layer, an i type amorphous silicon-based photoelectric conversion layer, and an n type semiconductor layer that compose an amorphous silicon-based thin film photoelectric conversion device is deposited under the following conditions. Silane-type gas as a main component of raw material gas which is supplied into a reaction chamber and dilution gas containing hydrogen are used, the flow rate of the dilution gas is four or less times that of the silane-type gas, the partial pressure of the silane-type gas in the plasma CVD reaction chamber ranges from 1.2 Torr to 5.0 Torr, and the distance between a surface of a substrate mounted on an anode electrode and a surface of a cathode electrode ranges from 8 mm to 15 mm. Accordingly, a method of manufacturing an amorphous silicon-based thin film photoelectric conversion device having a superior performance is obtained with an improved efficiency in the use of raw material gas as well as an enhanced deposition rate to achieve improvements in cost and efficiency in production. Even if the dilution gas is not used, the advantages above can be achieved under the same conditions as those described above except for the condition concerning dilution gas.

Method of manufacturing amorphous silicon based thin film photoelectric conversion device

A thin film photoelectric converter includes a polycrystalline photoelectric conversion layer (,) and a metal thin film (,) covering one main surface of the polycrystalline photoelectric layer. Polycrystalline photoelectric conversion layer (,) has an average thickness in the range from 0.5 to 20 &mgr;m and at least one of main surfaces of polycrystalline photoelectric conversion layer (,) has a textured surface structure. The textured structure has fine unevenness with level differences smaller than half of the thickness of polycrystalline photoelectric conversion layer (,) and substantially in the range from 0.05 to 3 &mgr;m.

Thin film photoelectric transducer

A method of fabricating a silicon-based thin-film photoelectric conversion device, where a plasma CVD process is used to deposit a polycrystalline photoelectric conversion layer. During the deposition of the photoelectric conversion layer, the temperature of the underlying layer is less than 550&deg; C., the pressure in the plasma chamber is more than 5 Torr, and the ratio of the flow rates of a hydrogen gas and a silane-type gas is more than 50. In addition, one of the following operations is carried out during the deposition to change the relevant parameters between the start and end of the deposition. First, the distance between the plasma discharge electrodes is increased gradually or in steps. Second, the pressure of the reaction chamber is increased gradually or in steps. Third, the flow rate of the silane-type gas is increased gradually. Fourth, the plasma discharge power density is reduced gradually or in steps.

Method of manufacturing silicon-based thin-film photoelectric conversion device

A p type semiconductor layer, an i type crystalline (polycrystalline, microcrystalline) photoelectric conversion layer, and an n type semiconductor layer are successively formed in the same plasma CVD deposition chamber. The p type semiconductor layer is produced on condition that the pressure in the deposition chamber is at least 5 Torr. Accordingly, a silicon-based thin film photoelectric conversion device having the p type semiconductor layer, the i type crystalline photoelectric conversion layer, and the n type semiconductor layer stacked on each other is manufactured. A method of manufacturing a silicon-based thin film photoelectric conversion device is thus implemented to produce a photoelectric conversion device having a superior performance and quality by a simple apparatus at a low cost and with high productivity.

Method of manufacturing silicon based thin film photoelectric conversion device

A p type semiconductor layer, an i type amorphous photoelectric conversion layer and an n type semiconductor layer of an amorphous type photoelectric conversion unit are formed in separate deposition chambers, respectively. A p type semiconductor layer, an i type crystalline photoelectric conversion layer and an n type semiconductor layer of crystalline type photoelectric conversion unit are formed continuously in one deposition chamber. Accordingly, a method of manufacturing a tandem type thin film photoelectric conversion device is obtained by which a tandem type thin film photoelectric conversion device having superior performance and high quality can be formed by a simple apparatus at a low cost with superior productivity.

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Kobe, Japan

Masashi Yoshimi