Gas production apparatus

Patent metadata

Field	Value
Publication number	US-2016010218-A1
Application number	US-201514865334-A
Country	US
Kind code	A1
Filing date	Sep 25, 2015
Priority date	Mar 28, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

A gas production apparatus is provided which includes: a module including a plurality of PN junctions connected in series to one another, each being formed of an inorganic semiconductor and having a light receiving surface; two gas generators that are provided at open ends of PN junctions at both extremities of the module, respectively, on a side of the light receiving surface; an electrolysis chamber which contains an aqueous electrolytic solution in contact with the two gas generators and contains gases generated by the two gas generators; and a diaphragm which is ion-permeable but gas-impermeable, and partitions the electrolysis chamber into two regions including the two gas generators, respectively, and containing hydrogen and oxygen, respectively.

First claim

What is claimed is:

1 . A gas production apparatus, comprising:
a PN junction module including a plurality of PN junctions connected in series to one another, each being formed of an inorganic semiconductor and having a light receiving surface on one side and a back surface on another side; two gas generators adapted to generate hydrogen gas and oxygen gas, respectively, that are provided at an open end of a PN junction at one extremity of the PN junction module and an open end of a PN junction at another extremity of the PN junction module, respectively, on a side of the PN junction module where the light receiving surface is located; an electrolysis chamber adapted to contain an aqueous electrolytic solution in contact with the two gas generators and contain gases generated by the two gas generators; and a diaphragm which is ion-permeable but gas-impermeable, and partitions the electrolysis chamber into two regions including the two gas generators, respectively, wherein the PN junction module is connected in series by connecting the back surface of a PN junction to the light receiving surface of an adjacent PN junction by a conductive material, and the two regions into which the electrolysis chamber is partitioned by the diaphragm are a region in which hydrogen generated by one of the two gas generators in contact with the aqueous electrolytic solution is contained and a region which contains oxygen generated by another of the two gas generators in contact with the aqueous electrolytic solution, with the hydrogen and the oxygen being generated when light is made incident on the light receiving surface in the PN junction module.

2 . The gas production apparatus according to claim 1 , further comprising a light transmitting insulating material which covers a surface of the conductive material in the PN junction module except for the two gas generators.

3 . The gas production apparatus according to claim 1 , wherein the inorganic semiconductor includes a CIGS compound semiconductor.

4 . The gas production apparatus according to claim 1 , wherein the inorganic semiconductor includes a CZTS compound semiconductor.

5 . The gas production apparatus according to claim 1 , wherein the inorganic semiconductor has an absorption wavelength edge equal to or greater than 800 nm.

6 . The gas production apparatus according to claim 1 , wherein:
N-side surfaces of the plurality of PN junctions each constitute the light receiving surface; P-side surfaces of the plurality of PN junctions each constitute the back surface; and the gas production apparatus further comprises back surface electrodes provided on the P-side surfaces of the plurality of PN junctions.

7 . The gas production apparatus according to claim 6 , wherein:
an N-side surface of the PN junction at the one extremity of the PN junction module serves as one of the two gas generators that generates hydrogen; and the gas production apparatus further comprises light transmitting conductive films made of a light transmitting conductive material that cover the N-side surfaces of the plurality of PN junctions of the PN junction module except for the PN junction at the one extremity, respectively.

8 . The gas production apparatus according to claim 6 , further comprising light transmitting conductive films made of a light transmitting conductive material that cover the N-side surfaces of the plurality of PN junctions,
wherein a light transmitting conductive film which covers an N-side surface of the PN junction at the one extremity of the PN junction module serves as one of the two gas generators that generates hydrogen.

9 . The gas production apparatus according to claim 6 , further comprising light transmitting conductive films made of a light transmitting conductive material that cover the N-side surfaces of the plurality of PN junctions, wherein:
one of the two gas generators that generates hydrogen is electrically connected to a light transmitting conductive film which covers an N-side surface of the PN junction at the one extremity of the PN junction module; and the diaphragm is provided between one of the two gas generators that generates hydrogen and the PN junction at the one extremity.

10 . The gas production apparatus according to claim 6 , wherein a back surface electrode provided on a P-side surface of the PN junction at the other extremity of the PN junction module partially serves as another of the two gas generators that generates oxygen.

11 . The gas production apparatus according to claim 6 , further comprising an inverse PN junction with reversed order of junction that is positioned on an extended portion of a back surface electrode provided on a P-side surface of the PN junction at the other extremity of the PN junction module, wherein:
a P-side surface of the inverse PN junction constitutes the light receiving surface; and an N-side surface of the inverse PN junction is brought into contact with the extended portion of the back surface electrode.

12 . The gas production apparatus according to claim 11 , wherein the P-side surface of the inverse PN junction serves as another of the two gas generators that generates oxygen.

13 . The gas production apparatus according to claim 11 , further comprising a light transmitting conductive film made of a light transmitting conductive material that covers the P-side surface of the inverse PN junction as the light receiving surface,
wherein the light transmitting conductive film which covers the P-side surface of the inverse PN junction serves as another of the two gas generators that generates oxygen.

14 . The gas production apparatus according to claim 6 , wherein:
an extended portion of a back surface electrode provided on a P-side surface of the PN junction at the other extremity of the PN junction module serves as another of the two gas generators that generates oxygen; and the diaphragm is provided between another of the two gas generators that generates oxygen and the PN junction at the other extremity of the PN junction module.

15 . The gas production apparatus according to claim 1 , further comprising a promoter positioned on a surface of at least one of the two gas generators.

16 . The gas production apparatus according to claim 15 , wherein the promoter positioned on the surface of one of the two gas generators that generates hydrogen is platinum as a hydrogen generation catalyst.

17 . The gas production apparatus according to claim 15 , wherein the promoter positioned on the surface of another of the two gas generators that generates oxygen is metal, CoO x or IrO 2 as an oxygen generation catalyst.

18 . The gas production apparatus according to claim 1 , wherein the plurality of PN junctions are equal to one another in amount of electric current generated by light irradiation.

19 . The gas production apparatus according to claim 1 , wherein the plurality of PN junctions are equal to one another in light receiving area of the light receiving surface.

Assignees

• Fujifilm Corp
• Japan Technological Res Ass Of Artificial Photosynthetic Chemical Process

Inventors

• Higashi Kohei

Classifications

• C25B11/04 Primary

  characterised by the material · CPC title

• Y02E10/541

  CuInSe2 material PV cells · CPC title

• H10F19/908

  for back-contact photovoltaic cells · CPC title

• H10F19/906

  characterised by the materials of the structures · CPC title

• H10F19/902

  for series or parallel connection of photovoltaic cells · CPC title