NL2011796C2 - High efficiency photoelectrochemical device for splitting water. - Google Patents
High efficiency photoelectrochemical device for splitting water. Download PDFInfo
- Publication number
- NL2011796C2 NL2011796C2 NL2011796A NL2011796A NL2011796C2 NL 2011796 C2 NL2011796 C2 NL 2011796C2 NL 2011796 A NL2011796 A NL 2011796A NL 2011796 A NL2011796 A NL 2011796A NL 2011796 C2 NL2011796 C2 NL 2011796C2
- Authority
- NL
- Netherlands
- Prior art keywords
- layer
- doped
- nanocrystalline
- intrinsic
- sic
- Prior art date
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims description 20
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 30
- 239000001257 hydrogen Substances 0.000 claims description 21
- 229910052739 hydrogen Inorganic materials 0.000 claims description 21
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 18
- 239000003792 electrolyte Substances 0.000 claims description 16
- 239000011159 matrix material Substances 0.000 claims description 16
- 229910021423 nanocrystalline silicon Inorganic materials 0.000 claims description 15
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 15
- 239000000758 substrate Substances 0.000 claims description 15
- 239000011521 glass Substances 0.000 claims description 11
- 229910052710 silicon Inorganic materials 0.000 claims description 10
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000010703 silicon Substances 0.000 claims description 7
- 238000000151 deposition Methods 0.000 claims description 6
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims description 6
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- 229910052796 boron Inorganic materials 0.000 claims description 4
- 238000003306 harvesting Methods 0.000 claims description 2
- 229910006404 SnO 2 Inorganic materials 0.000 claims 1
- 229910021431 alpha silicon carbide Inorganic materials 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 description 17
- 238000004519 manufacturing process Methods 0.000 description 11
- 230000008901 benefit Effects 0.000 description 9
- 229910021417 amorphous silicon Inorganic materials 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 230000005684 electric field Effects 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- 230000005855 radiation Effects 0.000 description 6
- 238000006722 reduction reaction Methods 0.000 description 6
- 238000013461 design Methods 0.000 description 5
- 239000004065 semiconductor Substances 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 238000005868 electrolysis reaction Methods 0.000 description 4
- 230000010354 integration Effects 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 3
- 239000004411 aluminium Substances 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 3
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- 230000002441 reversible effect Effects 0.000 description 3
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 3
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 2
- 229910021607 Silver chloride Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 229910052733 gallium Inorganic materials 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 2
- 238000006479 redox reaction Methods 0.000 description 2
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 102100038123 Teneurin-4 Human genes 0.000 description 1
- 101710122302 Teneurin-4 Proteins 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 229910001570 bauxite Inorganic materials 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000003776 cleavage reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 229910021419 crystalline silicon Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- -1 methane Chemical class 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- IIACRCGMVDHOTQ-UHFFFAOYSA-N sulfamic acid Chemical compound NS(O)(=O)=O IIACRCGMVDHOTQ-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- LSGOVYNHVSXFFJ-UHFFFAOYSA-N vanadate(3-) Chemical compound [O-][V]([O-])([O-])=O LSGOVYNHVSXFFJ-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier
- H01L31/075—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PIN type
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/50—Processes
- C25B1/55—Photoelectrolysis
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier
- H01L31/075—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PIN type
- H01L31/076—Multiple junction or tandem solar cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/548—Amorphous silicon PV cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/133—Renewable energy sources, e.g. sunlight
Description
High efficiency photoelectrochemical device for splitting water
FIELD OF THE INVENTION
The present invention is in the field of a high efficiency photoelectrochemical device for splitting water, a method of operating said device, an oxide type layer for use in said device and a method of producing said oxide layer.
BACKGROUND OF THE INVENTION
The present invention is in the field of electrical sustainable energy, and specifically relates to a photoelectrochemical device for splitting water.
The present invention relates to a specific type of an electrolytic cell. An electrolytic cell is an electrochemical cell that undergoes a chemical reaction, namely a redox reaction, when electrical energy is applied. In a sub domain, in a process called electrolysis, it relates to decomposition of a chemical compound. An electrolytic cell usually consists of two half cells.
Important examples of electrolysis are the decomposition of water into hydrogen and oxygen, as in the present case, and bauxite into aluminium and other chemicals.
An electrolytic cell has three functional parts, namely an electrolyte and two electrodes, a cathode and an anode. The electrolyte is usually a solution of a solvent, such as water, in which ions may dissolve. The electrolyte provides ions or charged species that flow to and from the electrodes (cathode and anode) under application of an external voltage. At the electrodes the actual reaction takes place, one reduction reaction and one oxidizing reaction, respectively. The reactions do not take place under "normal" or ambient conditions. The applied voltage (or potential) needs to be of sufficient magnitude, in order to carry out the reactions. It is noted that species formed, such as hydrogen and oxygen, would under normal conditions being brought into contact reverse the redox reaction.
The cathode is usually defined as the electrode to which cations (positively charged ions) flow, to be reduced by reacting with electrons (negatively charged) from that electrode. Likewise the anode is usually defined as the electrode to which anions (negatively charged ions) flow, to be oxidized by depositing electrons on the electrode.
Photoelectrochemical water-splitting devices typically use solar energy, i.e. solar radiation, to convert water into its components hydrogen and oxygen. The solar energy may be converted to electrical energy. The electrical energy (or potential) splits water. The obtained hydrogen is a source for e.g. combustion engines directly, or it can be converted into a hydrocarbon, such as methane, and then be used. The water splitting devices have been investigated for decades.
For converting solar energy typically multi-junction designs are most efficient, as they can absorb enough solar energy and provide sufficient free energy for water cleavage. However, complex devices come at high cost.. Typical solar-to-hydrogen (STH) conversion efficiencies are in the order of a few percent, being somewhat higher for complex designs, and somewhat lower for simple designs. A photoelectrochemical process is considered as a promising approach to split water into hydrogen and oxygen, using sunlight directly. Hydrogen may be considered as an energy source as well as an energy carrier. It has a high caloric value and upon combustion only water is produced.
In the prior art a photocathode has been proposed based on hydrogenated amorphous silicon carbide (a-SiC:H) layers. For producing such a layer typically a plasma enhanced chemical vapour technique (PECVD) is used. As a substrate a fluorine doped tin oxide (FTO) layer on glass may be used. Thereon a relatively thin doped a-SiC:H p-layer is deposited. On the p-doped layer a relatively thicker a-SiC:H intrinsic layer is deposited. Upon radiation with sunlight the cathode produces hydrogen (H2) and the anode produces oxygen (02) .
It has been found that the STH conversion of the above device is too low. Also the structure of the cathode is considered sub-optimal, e.g. in terms of photon to electron conversion efficiency. Further, the cathode is not designed optimally in view of the envisaged hydrogen production.
In general, there is room for improvement.
The present invention therefore relates to a high efficiency photoelectrochemical device being relatively simple of design and providing high conversion efficiencies, which solve one or more of the above problems and drawbacks of the prior art, providing reliable results, without jeopardizing functionality and advantages.
SUMMARY OF THE INVENTION
The present invention relates to a high efficiency photoelectrochemical device for splitting water. The device comprises an integrated cathode and an anode. In principle the anode may be integrated as well. Likewise an integrated anode is considered, with a cathode being provided further.
The present cathode comprises a sequence of layers. The layers are deposited on a substrate. Typically a flat substrate is selected, such as glass, silicon, such as a wafer, etc. The substrate may be treated, e.g. by providing a coating, such as fluorine-doped Sn02 coated glass.
The layers may be directly on top of one and another, or may comprise further (intermediate) layers.
In order to capture light a p-doped layer is provided, amongst others. For doping Group III (or Group 13) elements, such as boron, aluminium, Gallium and indium, are considered. It is preferred to use boron. A doping concentration for the present silicon based semiconductors is from 1013 cm-3 to 1018 cm-3, such as from 5*1014 cm-3 to 2*1017 cm-3.
The p-doped layer may be relatively thin, such as 5-100 nm, preferably 10-20 nm. It is preferred to use an amorphous SiC:H layer. Doping may be provided upon growing such a layer, or by ion implantation.
On the p-doped layer and intrinsic layer is provided. It is preferred to use an amorphous SiC:H layer. Also the intrinsic layer may be relatively thin, such as 10-50Ó nm, preferably 50-200 nm, though typically somewhat thicker than the p-doped layer.
This sequence of layers provides electrons from solar radiation, and thus a potential.
For carrying out the electrolysis an aqueous electrolyte is provided, such as aqueous H3NS03. The concentration of H3NS03 is preferably from 10"6 mole/1-10"1 mole/1, more preferably 10'5 mole/1-10'2 mole/1. The concentration is preferably not too high, in view of acidity of the solution. The is preferably not too low, in view of amount hydrogen being formed. The hydrogen is formed at the surface of the layer sequence.
The electrolyte further comprises a wire or the like, such as a noble metal wire, such as Pt and Pd. The wire is typically in electrical contact with a contact provided in the sequence f layers, such as an Al contact. As alternative materials a bismuth vanadate can be used. At the wire oxygen is formed.
The electrolyte is typically provided in a container, preferably an inert container.
It has been found that the STH conversion of the present device is much improved compared to the prior art. The present STH efficiency is in the order of 18%. Also the structure of the cathode is optimized, e.g. in terms of photon to electron conversion efficiency. Further, the cathode is designed optimally in view of the envisaged hydrogen production. The present device can now be operated without a need of an external bias voltage, which is considered a further advantage .
The present device provides a relatively high photocurrent density, such as -5 mA/cm2 at 0 V (versus reversible hydrogen electrode; RHE). Unless stated otherwise, for reasons of comparison, the current density is taken at 0 V (versus the reversible hydrogen electrode). Such corresponds to a solar-to-hydrogen (STH) efficiency of 6.3 % (relative to input of solar energy).
The present invention provides a simple design, using readily available resources, such as silicon.
The present device also relates to a cheap and effective membrane film, capable of separating hydrogen and oxygen. The present device is very stable in the environment provided, e.g. electrolyte. No degradation over time has been observed yet. Such is considered especially relevant in view of prior art catalyst and the like, which are less stable.
Of course integrating e.g. more layers makes e.g. deposition times longer. It has been found however that the benefits of the present device more than compensate for production drawbacks.
Further the present invention provides a method of operating the present device.
It is noted that the present device may also be applied for C02 reduction, water treatment, etc.
Also the present invention provides a nanocrystal-line-SiOx:H matrix layer comprising Si domains in the matrix for use in a photoelectrochemical device, and a method of producing said matrix layer.
The present device can be produced efficiently, e.g. in one multi-chamber cluster tool. Therein a p-dopant concentration, such as boron, may be reduced by tuning gas flows real time during the production process.
For a silicon based device the present device performs very well, comparable to much more complicated III-V devices. Such is considered important, as the present device can be, contrary to III-V devices, fully integrated in present silicon based semiconductor production technologies. The present device and its characteristics may be considered as a future benchmark.
Thereby the present invention provides a solution to one or more of the above mentioned problems and drawbacks.
Advantages of the present description are detailed throughout the description.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates in a first aspect to a high efficiency photoelectrochemical device for splitting water according to claim 1.
In an example of the present device the cathode comprises a contact, such as an Al contact, wherein the contact is integrated in the substrate layer. In principle the contact may be of any suitable conducting metal, such as Al, Cu, W,
Ti, and combinations thereof, as well as of any suitable semiconducting material. Preferably the material is suited to be integrated in a production process, such as a semi-conductor production process. It is an advantage of the present device that the contact can be integrated in an existing production process. Also the contact can be made of a readily available material.
In an example of the present device the p-doped layer comprises at least two sub-layers, wherein any p-doped layer closer to the substrate layer has a higher doping than any p-doped layer closer to the intrinsic layer, or wherein the doping continuously drops from a higher level to 0. It has been found that such a device has a higher conversion of photons to electrons, and as a result a higher STH ratio. With the present method a continuous doped layer can be made, having an initial doping concentration closer to the substrate and no doping at the intrinsic layer. It has been fund that especially a continuous doped layer has a high STH ratio. Likewise a semi-continuous stack of layers, such as a stack of 5-100 layers, provides a good STH ratio.
In an example of the present device the p-doped layer comprises 3-50 sub-layers. From a conversion point of view a higher number of layers would be preferred, from a manufacturing point of a view a lower number is preferred. In this respect a continuous decreasing dopant layer is preferred.
In an example of the present device between the intrinsic layer and electrolyte (f) at least one n-doped nanocrystalline (nc) layer is present, such as a nanocrystalline oxide layer, such as an nc-SiOx:H layer. Such a layer provides a good protection and does not jeopardize functionality of the present device.
In an example the present device further comprises one or more of (al) a photon reflector layer, preferably between the fluorine-doped Sn02 layer and glass substrate, especially for photons with a wavelength of 280-1000 nm, such as an Ag-layer, and an Al-layer, (b) a bottom cell, preferably comprising at least one p-doped layer, at least one intrinsic layer, and at least one n-doped layer, such as nc-Si:H layers, and (c) a top cell, preferably comprising at least one p-doped layer, at least one intrinsic layer, and at least one n-doped layer, such as nc-Si:H layers.
It has been found that a photon reflector layer increase the STH ratio with a few percent.
By providing a bottom and/or top cell a conversion of photons to electrons has been found to increase as well. As a result also the STH ratio increases. It has been found that the best results are obtained with a combination of p-doped, intrinsic, and n-doped layers. The doping concentration of the n-doped layers is similar to the p-doping concentration mentioned. Is has been found that especially nanocrystalline layers, such as Si:H layers perform well.
For doping of n-layers Group V (or Group 15) elements, such as phosphorus, aluminium, Gallium and indium, are considered. It is preferred to use phosphorous. A doping concentration for the present n-type silicon based semiconductors is from 1013 cm-3 to 1018 cm-3, such as from 5*1014 cm'3 to 2*1017 cm'3.
In an example the present device further comprises one or more of (v) a back contact, (w) a thin first a-SiC:H layer, comprising at least one p-doped layer, and at least one intrinsic layer, (y) a p-doped layer, such as a wafer substrate, and (z) a thin second a-SiC:H layer, comprising at least one intrinsic layer, and at least one n-doped layer.
The back contact may be fully integrated in the device and/or in the production process thereof.
In an example the present device comprises a 3-dimensional type structure, such as pillars, and a holographic raster. It has been found that especially the electrolytic reaction benefits from such a structure, e.g. in terms of selectivity, conversion and yield (of e.g. hydrogen).
In a second aspect the present invention relates to a method of operating a photoelectrochemical device according to the invention, comprising the steps of (i) applying light, and (ii) harvesting hydrogen.
The light applied is preferably from the sun (solar energy). As such the present invention provides a profitable way of converting sunlight into green energy, i.c. hydrogen.
In an example of the present method an external bias voltage is 0V or absent. Such is considered an advantage, as no extra measures have to be taken in order to operate the present device. Further, the advantages of the present device are not jeopardized at all.
In an example of the present method no current limitation is applied. Such is considered an advantage as well.
In a third aspect the present invention relates to a nanocrystalline-SiOx:H matrix layer comprising nanocrystalline Si domains in an oxide matrix for use in a photoelectrochemi-cal device. The present nanocrystalline-SiOx:H matrix layer provides an excellent coating with protective properties. It remains however transparent to optical radiation. It further does not jeopardize electrolytic functionality.
In an example the nanocrystalline-SiOx:H matrix layer comprises 10-50 wt. % Si domains, such as 20-35 wt. %.
In a fourth aspect the present invention relates to a method of producing a nanocrystalline-SiOx:H matrix layer comprising nanocrystalline Si domains in an oxide matrix, comprising the steps of providing SiH4, PH3, H2 and C02, and depositing the nanocrystalline-SiOx:H matrix layer comprising nanocrystalline Si domains.
SiH4 may be provided in an amount of 0.5-2 seem, such as 1 seem, PH3 may be provided in an amount of 0.5-2 seem, such as 1.2 seem, H2 may be provided in an amount of 50-200 seem, such as 100 seem, and C02 may be provided in an amount of 0.5-2 seem, such as 1.6 seem.
The one or more of the above examples and embodiments may be combined, falling within the scope of the invention.
EXAMPLES/EXPERIMENTS
The present invention relies on scientific research carried out at the Technical University Delft, the Netherlands . Various results and background of these experiments will be published in a PhD-Thesis by Lihao Han. The results and background of the experiments are incorporated into the present application by reference.
Some details are given below. PECVD fabrication
In an example an a-SiC:H photocathodes were deposited by a radio frequency (RF-) PECVD multi-chamber tool. A 2.5 cm x 10 cm Asahi vu-type substrate, with a thick (~600 nm) fluorine-doped Sn02 (FTO) on textured glass, was heated at 170°C during the deposition.
In an example an a-SiC:H(B) layer was deposited as the p-layer, decomposed from SiH4( CH4, and B2H6 diluted H2 gas flow in a controlled pressure. The gradient B doping layer was deposited by a programmed 10-step recipe in which 2 seem H2 diluted B2H6 gas flow rate was evenly reduced per 72 seconds from the same B concentration as the initial p-layer until 0 seem like the i-layer. A H2 treatment is followed in the same chamber in order to improve the p/i interface. The i-type a-SiC:H was deposited in another chamber specifically to avoid the possible contamination.
In an example after a-SiC:H thin films were synthesized, a stripe of 300 nm Al was coated on the pre-covered region of the sample as the front contact using a Provac evaporator in rotation mode. The purpose of the Al stripe is to insure the generated photocurrent can be effectively collected.
In an example PEC characterization was carried out in a three-electrodes configuration, where an a-SiC:H device with a reaction area of 0.283 cm2 (an illuminated hole of 6 mm in diameter) was acting as the working photocathode, a coiled Pt wire as the counter electrode, and an Ag/AgCl electrode (XR300, saturated KC1 and AgCl solution, Radiometer Analytical) as the reference electrodes, respectively, 0.1 M (mole/L). Sulphamic acid (H3NS03) was utilized as the electrolyte, buffered to pH -3.75 by potassium bi-phthalate (KHP).
The following equation was used to convert the potential vs. the reference cell into the potential vs. RHE [ref]:
Erhe = EAg/Agci + E0Ag/Agci vs. RHE + 0.059xpH
The invention is further detailed by the accompanying figures, which are exemplary and explanatory of nature and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protection, defined by the present claims.
FIGURES
The invention although described in detailed explanatory context may be best understood in conjunction with the accompanying figures.
Fig. 1 shows a basic photocathode.
Fig. 2 shows a gradient doped cathode.
Fig. 3 shows an N-type nanocrystalline silicon oxide technique on the photocathode .
Fig. 4 shows a tandem solar cell integration with the photocathode to provide the over-potential for water reduction
Fig. 5 shows a HIT (Hetero-structure with Intrinsic Thin Layer) solar cell integration with the photocathode to provide the over-potential for water reduction without any current limitation.
Fig. 6 shows a current density versus electrical field.
Fig. 7 shows a current density versus electrical field.
Fig. 8 shows a current density versus electrical field. DETAILED DESCRIPTION OF THE FIGURES Fig. 1 shows a basic photocathode. Therein 1. 4H+ + 4e“ -> 2H2| 2 . 2H20 - 4e~ ^ 4H+ + 02t
3. ί-type a-SiC:H
4 . p-type a-SiC:H
5 . FTO 6. glass (textured for light management) 7. Al contact 8 . H3NSO3 electrolyte 9. Pt
Fig. 2 shows a gradient doped cathode. Therein
1. 4H+ + 4e‘ -» 2H2T 2 . 2H20 - 4e~ -> 4H+ + 02t
3. 2-type a-SiC:H 4. p-- -type a-SiC:H (gradient reducing B doping)
5. p-type a-SiC:H
6. FTO 7. glass (textured for light management) 8. Al contact 9. H3NSO3 electrolyte 10. Pt
Fig. 3 shows an N-type nanocrystalline silicon oxide technique on the photocathode. Therein 1. 4H+ + 4e“ -> 2H21 2 . 2H20 - 4e' -► 4H+ + 02t
3. n-type nc-SiOx:H
4. i-type a-SiC:H 5. p— -type a-SiC:H (gradient reducing B doping)
6. p-type a-SiC:H
7 . FTO 8. glass (textured for light management) 9 . Al contact 10. H3NSO3 electrolyte 11. Pt
Fig. 4 shows a tandem solar cell integration with the photocathode to provide the over-potential for water reduction. Therein 1. 4H+ + 4e' -* 2H2f 2. 2H20 - 4e“ 4H+ + 02|
3. n-type nc-SiOx:H
4. i-type a-SiC:H 5. p-- -type a-SiC:H (gradient reducing B doping)
6. p-type a-SiC:H
7 . i-type nc-Si:H
8. p-type nc-SiOx:H
9 . FTO 10 . back reflector 11. glass (textured for light management) 12 . H3NSO3 electrolyte 13 . Pt
Fig. 5 shows a HIT (Hetero-structure with Intrinsic Thin Layer) solar cell integration with the photocathode to provide the over-potential for water reduction without any current limitation. Therein 1. 4H+ + 4e' -+ 2H21 2. 2H20 - 4e' -+ 4H+ + 02t
3. n-type nc-SiOx:H
4. i-type a-SiC:H 5. p-- -type a-SiC:H (gradient reducing B doping)
6. p-type a-SiC:H
7. n-type a-Si:H
8. i-type a-Si:H 9. p-type c-Si wafer
10. p-type a-Si:H 11. back contact 12 . H3NSO3 electrolyte 13 . Pt
Fig. 6 shows a current density versus electrical field. Therein a "normal" layer (a), having a 10 nm p-doped layer and a 80 nm intrinsic layer, a reference p/i junction layer (b), having a 50 nm p-doped layer and a 40 nm intrinsic layer, a doping profile (c), having a 10 nm p-doped layer, a 40 nm intermediate less doped p-layer, and a 40 nm intrinsic layer, and (d) a gradient doped profile, having a 10 nm p-doped layer, ten 4 nm intermediate in a sequence continuously less doped p-layer, and a 40 nm intrinsic layer, are compared in view of current density j (mA/cm2) versus applied field. Clearly the present continuously doped profile provides the highest current density.
Fig. 7 shows a current density versus electrical field. Therein a photocathodes with (a) and without an n-nc-SiOx:H layer (b) is shown. The radiation is provided in an on-off mode. In the off mode it can be seen that no current density is present. No electrolysis takes place. If radiation is present, at a lower (more negative) electrical field a higher current density is observed. In comparison, the photocathode with the n-nc-SiOx:H layer (b) has a higher current density.
Fig. 8 shows a current density versus electrical field for various solar cells. The measurement is comparable with that of figure 7. Therein an a-SiC:H photocathode is shown. The photocathode is integrated with a-Si:H/a-Si:H (a), with nc-Si:H/a-Si:H (b) , with nc-Si :H/nc-Si:H (c) , with a-Si:H (d), and without PV (e). The cathode without PV has a small onset potential of about -0.2 V. All other cathodes have an onset potential of about 1.0 V, which is very advantageous for use in a hydrogen producing electrolytic cell.
In the tables below deposition data of the structures 1-5 (equivalent to a-e) are given.
Table 1
Claims (14)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2011796A NL2011796C2 (en) | 2013-11-13 | 2013-11-13 | High efficiency photoelectrochemical device for splitting water. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2011796A NL2011796C2 (en) | 2013-11-13 | 2013-11-13 | High efficiency photoelectrochemical device for splitting water. |
| NL2011796 | 2013-11-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NL2011796C2 true NL2011796C2 (en) | 2015-05-19 |
Family
ID=50156848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL2011796A NL2011796C2 (en) | 2013-11-13 | 2013-11-13 | High efficiency photoelectrochemical device for splitting water. |
Country Status (1)
| Country | Link |
|---|---|
| NL (1) | NL2011796C2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4798808A (en) * | 1986-03-11 | 1989-01-17 | Atlantic Richfield Company | Photoconductive device coontaining electroless metal deposited conductive layer |
| WO2004050961A1 (en) * | 2002-11-27 | 2004-06-17 | University Of Toledo, The | Integrated photoelectrochemical cell and system having a liquid electrolyte |
| US20100282601A1 (en) * | 2008-10-30 | 2010-11-11 | Panasonic Corporation | Photoelectrochemical cell and energy system using the same |
| US20130019929A1 (en) * | 2011-07-19 | 2013-01-24 | International Business Machines | Reduction of light induced degradation by minimizing band offset |
| EP2573209A1 (en) * | 2010-05-19 | 2013-03-27 | Sharp Kabushiki Kaisha | Solar-cell-integrated gas production device |
-
2013
- 2013-11-13 NL NL2011796A patent/NL2011796C2/en not_active IP Right Cessation
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4798808A (en) * | 1986-03-11 | 1989-01-17 | Atlantic Richfield Company | Photoconductive device coontaining electroless metal deposited conductive layer |
| WO2004050961A1 (en) * | 2002-11-27 | 2004-06-17 | University Of Toledo, The | Integrated photoelectrochemical cell and system having a liquid electrolyte |
| US20100282601A1 (en) * | 2008-10-30 | 2010-11-11 | Panasonic Corporation | Photoelectrochemical cell and energy system using the same |
| EP2573209A1 (en) * | 2010-05-19 | 2013-03-27 | Sharp Kabushiki Kaisha | Solar-cell-integrated gas production device |
| US20130019929A1 (en) * | 2011-07-19 | 2013-01-24 | International Business Machines | Reduction of light induced degradation by minimizing band offset |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Luo et al. | Single-crystal silicon-based electrodes for unbiased solar water splitting: current status and prospects | |
| Kang et al. | Printed assemblies of GaAs photoelectrodes with decoupled optical and reactive interfaces for unassisted solar water splitting | |
| Nogay et al. | Nanocrystalline silicon carrier collectors for silicon heterojunction solar cells and impact on low-temperature device characteristics | |
| Young et al. | Photo-assisted water oxidation with cobalt-based catalyst formed from thin-film cobalt metal on silicon photoanodes | |
| Bae et al. | Carrier-selective p-and n-contacts for efficient and stable photocatalytic water reduction | |
| Feng et al. | Nickel-coated silicon photocathode for water splitting in alkaline electrolytes | |
| US9252316B2 (en) | Ultra thin hit solar cell and fabricating method of the same | |
| Digdaya et al. | Extracting large photovoltages from a-SiC photocathodes with an amorphous TiO 2 front surface field layer for solar hydrogen evolution | |
| CA2923897C (en) | Photocathodes and dual photoelectrodes for nanowire photonic devices | |
| Han et al. | Gradient dopant profiling and spectral utilization of monolithic thin-film silicon photoelectrochemical tandem devices for solar water splitting | |
| Urbain et al. | a-Si: H/µc-Si: H tandem junction based photocathodes with high open-circuit voltage for efficient hydrogen production | |
| Urbain et al. | Development of thin film amorphous silicon tandem junction based photocathodes providing high open-circuit voltages for hydrogen production | |
| KR100928302B1 (en) | Method for manufacturing solar cell of tricrystalline silicon using surfactant and acid solution wet etching method | |
| CN102220615B (en) | Method for preparing CdS/ZnO nanotube array photoelectrode | |
| US20120216854A1 (en) | Surface-Passivated Regenerative Photovoltaic and Hybrid Regenerative Photovoltaic/Photosynthetic Electrochemical Cell | |
| Han et al. | Optimization of amorphous silicon double junction solar cells for an efficient photoelectrochemical water splitting device based on a bismuth vanadate photoanode | |
| Jung et al. | Dynamic Photoelectrochemical Device Using an Electrolyte-Permeable NiO x/SiO2/Si Photocathode with an Open-Circuit Potential of 0.75 V | |
| US20130174896A1 (en) | Tandem solar cell using a silicon microwire array and amorphous silicon photovoltaic layer | |
| Chen et al. | Yttrium fluoride-based electron-selective contacts for crystalline silicon solar cells | |
| Qin et al. | Fabricating high-quality Cu2O photocathode by magnetron sputtering: insight into defect states and charge carrier collection in Cu2O | |
| Pandey et al. | Facile single step synthesis of Cu2ZnSnS4 thin films by sputtering from a single target and their electrical characterization | |
| NL2011796C2 (en) | High efficiency photoelectrochemical device for splitting water. | |
| JPH0544198B2 (en) | ||
| US20220262964A1 (en) | Semiconductor device and solar cell and production method for semiconductor device | |
| KR20110044442A (en) | Transparent electrode for a thin film solar cell and fabricating method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MM | Lapsed because of non-payment of the annual fee |
Effective date: 20161201 |