CN102683482A - Method for forming a bifacial thin film photovoltaic cell and thin film solar device - Google Patents
Method for forming a bifacial thin film photovoltaic cell and thin film solar device Download PDFInfo
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Abstract
The invention provides a method for forming a bifacial thin film photovoltaic cell and a thin film solar device. The method for forming the bifacial thin film photovoltaic cell includes providing a glass substrate having a surface region covered by an intermediate layer and forming a thin film photovoltaic cell on the surface region. Additionally, the thin film photovoltaic cell includes an anode overlying the intermediate layer, an absorber over the anode, and a window layer and cathode over the absorber mediated by a buffer layer. The anode comprises an aluminum doped zinc oxide (AZO) layer forming a first interface with the intermediate layer and a second interface with the absorber. The AZO layer is configured to induce Fermi level pinning at the first interface and a strain field from the first interface to the second interface.
Description
Technical field
Present invention relates in general to photovoltaic devices and manufacturing approach.More particularly, the invention provides a kind of method and apparatus structure that is used for the two-side film membrane photovoltaic cell.Execution mode of the present invention comprises a kind of method that is used to form the two-side film membrane photovoltaic devices, and this method utilizes the strain field in fermi level pinning (Fermi level pinning) and the anode to change internal electric field so that improve battery efficiency.An application of the present invention is that the AZO layer of strain is assembled to be used to the strengthening hole as the interface between PV absorber and the anode layer.
Background technology
Human from beginning most just to have attempted seeking the method for utilizing energy.The form that energy appears such as petrochemistry, hydroelectric power generation, nuclear, wind, biomass (biomass, biomass), solar energy and such as timber and coal.In last century, modern civilization has relied on the petrochemistry energy as important energy source.The petrochemistry energy comprises natural gas and oil.This comprises and is generally used for also comprising the gasoline, diesel oil and the jet fuel that are generally used for the traffic purpose for domestic heat with the light form such as butane and propane of the fuel that acts on culinary art.Petrochemical heavier form can also be used for domestic heat in some places.Unfortunately, the supply of petrochemistry fuel is limited, and come down to fix based on this supply of obtainable amount on the earth.In addition, Along with people's uses the amount of petroleum product more and more, so it becomes scarce resource fast.
Expect clean environment and the reproducible energy.The instance of clean energy resource is hydroelectric electric power.Hydroelectric power generation electric power stems from the generator of the water current driven that is produced by dam.That cleans also comprises wind, ripple, biomass etc. with the reproducible energy.Windmill converts wind energy into the more energy of useful form, such as.Other forms of clean energy resource comprise solar energy.
Heliotechnics will convert the energy of other useful forms generally from the electromagnetic radiation of the sun to.These other forms of energy comprise heat energy and electric power.For Electric Application, often use solar cell.Though solar energy is clean environment, and succeeds, also leave many restrictions that need solution before the extensive use in the whole world at it on a degree.As an example, one type solar cell uses the crystalline material that stems from semi-conducting material ingot (ingot, rod).These crystalline materials can be used to make photovoltaic devices, and this photovoltaic devices comprises photovoltaic and the optical diode device that electromagnetic radiation is converted into electric power.But crystalline material is more expensive usually, and is difficult to extensive manufacturing.The film that solar cell use " film " technology of other types forms light-sensitive material is to be used for converting electromagnetic radiation to electric power.For in making the solar cell process, using thin film technique, have similar restriction.That is, efficient is lower usually.In addition, the film reliability is lower usually, and in traditional environment is used, can not use for a long time.Usually, film is difficult to be integral with each other through mechanical system.These of these conventional arts can find from whole specification with other restrictions, and will more specifically describe below.
As the effort of the efficient of improving thin-film solar cells, be used for improving the process that to be with arrangement relatively and play important effect in the final performance that improves solar cell at the heterojunction place of battery.When the material of selecting to be used to form film PV battery knot (junction) interface and structure, there is a multiple manufacturing difficult problem with suitable electric field strength and direction.Specifically, between absorber and the anode or between window layer and the negative electrode band through respective interface to the straight collection efficiency of charge carrier and the built-in voltage of battery of influencing.Although some in having solved these problems in the conventional art in the past, conventional art is normally inadequate in multiple situation.Therefore, expectation has improved method and structure so that be designed for the battery junction interface of film photovoltaic device.
Summary of the invention
The invention provides a kind of method that is used to form the two-side film membrane photovoltaic cell.This method comprises: provide to have to form the coating photovoltaic cell by the glass substrate in intermediate layer covered surfaces zone and on surf zone.Film photovoltaic cell comprises the anode that covers said intermediate layer, the absorber that is positioned at said anode top.In addition, battery comprises and is positioned at said absorber top window layer and negative electrode to have resilient coating between window layer and the negative electrode.Anode comprises zinc oxide (AZO) layer that aluminium mixes, and is used for forming first interface and forming second contact surface with absorber with the intermediate layer.AZO is configured to cause first at the interface other pinning of Fermi level and the strain field from first interface to second contact surface.
In interchangeable execution mode of the present invention, the thin film solar device of the AZO layer of the strain that is used for anode absorber interface is provided.This device comprises optically transparent substrate and the intermediate layer that covers transparency carrier.In addition, this device comprises anode layer, and anode layer comprises that zinc oxide (AZO) layer of aluminium doping is so that form first interface with the intermediate layer.This device also comprises absorber, and absorber comprises that the copper indium gallium diselenide with p-type dopant is to form second contact surface with the AZO layer.In addition, this device comprises resilient coating, at the resilient coating heel with the window layer that covers absorber is arranged.In addition, this device comprises the negative electrode that covers the window layer.In an embodiment, the AZO layer that this device utilized causes that strain field and first fermi level pinning at the interface in the anode layer is so that change the internal electric field at second contact surface place.
The method that execution modes more of the present invention provide a kind of combination that utilizes strain and fermi level pinning at the interface in the anode to change the internal electric field around anode-absorber interface is to reduce electric field strength or even the direction of upset internal electric field.The internal electric field intensity that reduces descends so that cross the arrival anode by the charge carrier hole from the absorber tunnelling more easily barrier.At the interface the reverses direction of internal electric field between absorber and rear electrode directly helps to assemble through the hole of n+ type anode from p-type absorber.
The intermediate layer is arranged between the surf zone of AZO layer and substrate.Lattice mismatch between AZO layer and the intermediate layer (1attice mismatch) makes and produces strain in the anode that this strain has changed the electric field at the interface between anode and the absorber.Between AZO layer and the intermediate layer or between AZO layer and the absorber at the interface, the electronics band is changed through surface state and aims at via fermi level pinning across the interface.Strain in fermi level pinning and the anode all can make internal electric field reduce at the rear electrode place or even reverses direction, this helps hole in the gathering of contact position, back and improved battery efficiency thus.
Description of drawings
Fig. 1 shows the figure that utilizes the film photovoltaic cell of aluminium doped zinc oxide layer at the anode absorber at the interface;
Fig. 2 shows the figure across the internal electric field at the interface of absorber and typical bilateral structure thereof;
Fig. 3 A shows the figure of the heterojunction energy band structure of two-sided battery;
Fig. 3 B is the nearer view in anode-absorber energy band structure at the interface of two-sided battery;
Fig. 4 is the figure that the strain films that comprises the interface with mismatched lattices two kinds of materials at interval is shown;
Fig. 5 is the figure of the internal electric field that changes at the interface at anode-absorber according to the combined effect of an embodiment of the invention through strain in the anode and interface fermi level pinning.
Fig. 6 is the image that the cross section SEM of the sputter AZO layer with cylinder form is shown; And
Fig. 7 shows the figure of the X-ray diffraction pattern of the sputter zinc oxide layer with Wurzite structure, and it shows in the raw the element cell with stress state.
Embodiment
Execution mode of the present invention provides a kind of method and apparatus that is used for the two-side film membrane photovoltaic cell.Execution mode of the present invention comprises and is used for utilizing strain field and interface fermi level pinning to form the method for two-side film membrane photovoltaic devices at anode layer, thereby improves battery efficiency to change at anode absorber internal electric field at the interface.Provide a kind of, assembled (hole collection) so that strengthen the hole with the device of AZO layer as the interface between PV absorber and the anode layer.
Fig. 1 shows the figure that utilizes the film photovoltaic cell of aluminium doped zinc oxide layer according to the embodiment of the present invention at the anode absorber at the interface.As shown in the figure, film photovoltaic (PV) battery is formed on the substrate 101.Usually, for two-side film membrane PV battery, for substrate selects for example to receive the transparent material of lime glass.In execution mode, intermediate layer 105 forms the surf zone of covered substrate 101.Intermediate layer 105 is the basic units that are used for rear electrode (typically being anode).In an embodiment, intermediate layer 105 can be diffused into the electrode layer from receiving lime glass to prevent sodium element as barrier.
In another embodiment, intermediate layer 105 is optically transparent for sunlight, absorbs with convenient rear side from battery.The oxide skin(coating) that intermediate layer 105 is preferably transparent, the material that this oxide skin(coating) is selected from tin-oxide (TFO), indium tin oxide (ITO) and silicon dioxide or silicon nitride that fluorine mixes is processed.In another embodiment, if but select conductive material, then intermediate layer 105 can become the part of the rear electrode of battery 100, and the intermediate layer is configured to form and is used for electrically contacting of galvanic anode.The film that for example, can comprise transparent conductive oxide and/or metal (such as molybdenum) in the intermediate layer 105.In addition, intermediate layer 105 can be used as structure basic unit, to be used for being provided with the strain field of controlling the layer that covers himself growth at the lattice of preset range internal constant through a side that makes the interface.The layer that is formed on its top can controllably form under strain based on lattice mismatch.
As shown in Figure 1, anode layer 110 forms and covers intermediate layer 105.In an embodiment, anode layer 110 is aluminium doped zinc oxide (AZO) layers, so that between AZO layer 110 and intermediate layer 105, form first interface 107 at least.The film of aluminium doped zinc oxide is transparent and conducts electricity.The optical characteristics of AZO is characterised in that in visible range, to have high-transmission rate, and concerning the IR wavelength of～12 μ m length, has useful transmissivity.AZO layer 110 can through from by the Al metal that is combined in the 2-4% the ZnO (perhaps with A1
2O
3Form) the target sputter formed and deposit.AZO layer 110 can pass through RF or the deposit of DC magnetron, wherein is about 3W/cm in the vacuum chamber of the pressure limit of about 1-10mtorr (millitorr) energy density that hits
2Perhaps lower, oxygen and argon gas gaseous mixture flow in vacuum chamber.Replacedly, the AZO layer can form through the method for using MOCVD.On intermediate layer 105, form after the AZO layer, the aluminium that is used as n-type dopant is at n
+Can have in the anode from 5x10
19Cm
-3To 1x10
21Cm
-3The atomic energy level that changes.Conductance (it is as specific volume resistance or as the sheet drag measurement) relevant with deposition characteristics and layer thickness.
With reference to Fig. 1, absorber 115 forms and covers AZO layer 110, makes between anode 110 and absorber 115, to form second contact surface 112 at least.The absorber 115 of battery 100 is photovoltaic materials, typically is p-N-type semiconductor N film.In a specific execution mode, form absorber 115 through heat treatment precursor layer in gaseous environment.For example, the precursor layer that comprises copper, phosphide element and/or indium-gallium element can utilize sputter to be formed on the surface of substrate.In the subsequent reaction heat treatment process, precursor layer can be handled in inherent gaseous environment such as the boiler tube that comprises selenides material (species), sulfur material and nitrogen material etc. reactively.When boiler tube was heated, gaseous state selenium acted on the copper-indium-gallium material mutually in precursor layer.Because reactive heat treatment, so precursor layer is converted into the photovoltaic film lamination that comprises copper indium (gallium) diselenide (CIS/CIGS) compound, this photovoltaic film lamination is p-N-type semiconductor N and the absorber layer that is used to form photovoltaic cell.
The U.S. Patent application No.61/178 that can be called " Method and System for Selenization in Fabricating CIGS/CIS Solar Cells (making the method and system that is used for selenizing in the CIGS/CIS solar cell) " about more detailed descriptions of the heat treatment process of the CIGS photovoltaic film lamination that is used to form thin-film solar cells in the name that on May 14th, 2009 was submitted to by Robert Wieting; Find in 459; This U.S. Patent application is given the Stion Corporation of san jose by co-assigned, and this U.S. Patent application is incorporated into this by reference.In some embodiments, absorber 115 can be processed by the cadmium tellurium compound semiconductor with p-type dopant.Certainly, other modification, modification and alternative can be arranged.For example, absorber is depicted as the structure of single knot here, but this absorber can replacedly be formed in the battery with two or more knots or in having the battery of two or more knots, repeat changeably.
Above absorber 115, battery 100 comprises window layer 125.In an embodiment, can be inserted with resilient coating 120 between window layer 125 and the absorber 115.The electrical characteristics of resilient coating 120 are n-types, and the electrical characteristics of window layer 125 are n+ types.In one embodiment, resilient coating 120 can use chemical bath deposition (CBD) method to be processed by the cadmium sulfide compound.In another embodiment, resilient coating can use the MOCVD method to process through zinc oxide.Replace sputtering method, use the MOCVD method to form the zinc oxide resilient coating, thereby can reduce the possible structural damage that causes by sputtering technology greatly second contact surface.In preferred embodiment, window layer 125 is the AZO layers with thickness thinner than absorber 115.In some embodiments, window layer 125 can be used to form the negative electrode contact of solar cell.Replacedly, can utilize the MOCVD method to increase the extra play of being processed by the boron doped zinc oxide, the front end that has the n+ electrical characteristics with formation electrically contacts.
In order to construct thin-film solar cells, used two-sided battery structure, purpose is to strengthen photonic absorption from the both sides of absorber.Fig. 2 show across the interface of absorber and typical bilateral structure thereof the reduced graph of internal electric field.In this structure, anode and cathode layer are processed by the AZO material with n+ electrical characteristics, and p-type absorber is interposed in therebetween.Because structure construction under equilibrium condition and electrical characteristics, two internal electric fields at the interface of absorber all can have the direction of pointing to absorber from electrically contacting.As shown in Figure 2, specifically, electric field E3 points to p-type absorber at contact point place, back.This structure is opaque for the gathering in hole.In other words, the signal of E3 is against the transmission of hole from absorber to back contact.Aspect energy, the intensity of internal electric field is associated with firm energy barrier and passes through so that tunnel is worn in the hole.
Fig. 3 A shows the reduced graph of the heterojunction band structure of two-sided battery.It shows the valence band EV and the conduction band Ec of typical two-sided battery structure, and wherein the n+ transparent oxide is as back contact, the anode contact on the left side and the negative electrode contact on the right side.Fig. 3 B be the anode absorber band structure at the interface of two-sided battery near view.As shown in the figure, barrier is present in anode-absorber at the interface, makes battery to rely on tunnelling current so that through back contact the charge carrier hole is assembled.The hole does not have usually and is used to launch thermionic enough energy.Internal electric field is relative with the tunnelling in hole through pointing to absorber here.Do not have the gathering in effective charge carrier hole, solar cell can not produce sufficiently high PV electric current as the basis that is used to have high efficiency solar cell.Therefore, need to use mechanism to come to reduce the tunnelling barrier or even change signal at anode-absorber internal electric field at the interface to help tunnelling current through changing internal electric field in the anode.
The invention provides a kind of method of utilizing rear electrode structural change internal electric field, the rear electrode structure comprises the AZO material, and this material covers the intermediate layer on the surf zone that at first is arranged in (transparent) substrate.This method comprises utilizes the lattice mismatch strain to change the internal electric field across anode-absorber interface.Fig. 4 illustrates the strain films that comprises the interface with mismatched lattices two kinds of materials at interval.As shown in the figure; Different crystalline lattice two kinds of materials A and the B at interval that have in being in each nature is disposed in a time-out; Such as being arranged together through growth B material layer on the A material layer, two layers all meet to reach the epuilibrium thermodynamics state that the free energy that makes the A+B system reduces.Material B has lattice constant α
1, lattice constant α
1Lattice constant α greater than materials A
0Material B will be under the compression stress the less lattice with adaptation material A, and the latter will be under the tensile stress simultaneously.The strain of each in two layers (one of them is in compression and and is in stretching) can be directly and (α
1-α
0)/α
0Value relevant.
The characteristic that is in the film under the stress changes with respect to their natural states that does not stress.For example, the recombination rate of energy band aligning, carrier mobility, minority carrier, state density, piezoelectric field etc. are owing to the strain in the film changes.Through structural interface structure suitably, above-mentioned physical characteristic alternately can be and Be Controlled according to interfacial structure.This provides and has been used to make up the basis based on the plural layers of photovoltaic junction, and this has satisfied the solar energy equipment performance demands of expectation.Specifically, according to the embodiment of the present invention, the charge carrier collection efficiency of the solar cell of based thin film can be enhanced through using the strain in the anode, is used for assembling from absorber the tunnelling barrier in hole with minimizing.As shown in Figure 3, be present between anode and the absorber by the definite energy barrier of conduction band skew (band rank, band offset).The band skew of expectation can be in the scope from 0.1eV to 0.3eV.Relative band between the multiple material in the battery is aimed at attribute and and then the definite battery efficiency factor of confirming the IV curve.The discontinuity (particularly those in the conduction band are discontinuous) of band causes irregular perhaps " kinking " in the battery IV curve.In the solar cell of based thin film, aiming at the relative band at heterojunction place is the principal element when confirming final performance.Field at the knot place is rational for electronics with hole separating in space charge region.Be diffused into the edge of space charge region at the charge carrier of quasi-neutrality region generating, drift about down in this place's charge carrier influence at internal electric field.When the strain in the anode layer was changed and internal electric field is changed thus, aiming at band at the interface can be by adjustment to help helping the gathering in charge carrier hole.For example, can reduce internal electric field, thereby make that the energy barrier that is used for tunneled holes can be reduced greatly.Perhaps, internal electric field is turned to relative direction towards anode, directly helps carrier flow.
Another influence that influences the anode-material at absorber interface and the selection of structure is included in the phenomenon of fermi level pinning at the interface.The surface of pinning can make diode (diode, commutator) reduce also thereby the photovoltaic response of battery is reduced, to put forward the performance that changes battery.Most semiconductor has the dangling bonds that have fracture in chemically active surface.Asymmetric fracture in crystal potential energy makes and forms the energy state as the intermediate gaps defective shape of recombination center.These surface state possibly be that determining cause is plain really in Fermi level (the replacing the intrinsic carrier level) position.The scope that fermi level pinning arrives is confirmed by the density of said surface state, cross section and their positions in energy band that they obtain.In the order forming process of film lamination, because the upper strata covers lower floor, so surface state generally remains at the interface.The pinning of the Fermi level through interface state makes across the space charge region " freezing " at interface, that is, its confirms in advance that band from the absorber to the anode is aimed at and be crooked, and does not consider the doping rank across arbitrary layer at interface.
Fig. 5 is at anode-absorber figure of the internal electric field of the change of the combination through strain in the anode and interface fermi level pinning at the interface according to an embodiment of the invention.As shown in the figure, before intermediate layer 105 is arranged on the substrate 101 at formation anode layer 110 (and forming absorbed layer 115 subsequently).In some embodiments, intermediate layer 105 is played at least two effects through changing internal electric field wherein for the double-sided solar battery that improves based thin film.The intermediate layer forms first interface 107 between n+ semiconductor AZO layer 110 and intermediate layer 105.First at the interface, the chemical bond of arbitrary layer fracture in two layers and interface atom are constructed and are made and form interface state, and this directly causes the fermi level pinning effect.In addition, the fermi level pinning 111 of the fermi level pinning 108 at 107 places, first interface and second contact surface 112 places (it is between the absorber 115 of AZO layer 110 and formation afterwards) couples.Because at the interface fermi level pinning 108 and 111, the energy barrier that is used for tunneled holes can be adjusted to help improving the combination again in electronics-hole that the charge carrier collection efficiency reduces to be caused by light simultaneously.
Secondly; The basic unit that is used to form AZO layer 110 has been set in the intermediate layer 105 that is formed on glass substrate 101 tops, and this basic unit can be utilized so that be controlled at the lattice mismatch strain in the AZO layer 110 that forms subsequently better than the AZO layer directly being arranged in glass substrate 101 tops.In one embodiment, the material and the thickness in intermediate layer 105 are used as engineering parameter, so that in AZO layer 110, adjust strain field.For example, the intermediate layer can comprise the material with one (on average) lattice constant (this lattice constant is less than the lattice constant of AZO layer), is in compressive state so that covering AZO layer is controlled as.The intermediate layer can comprise having the more material of macrolattice constant, so that the strain field that covers in the AZO layer can be converted into tensile properties.The AZO layer can be doped with the sputtering technology formation of the zinc or the zinc oxide target of aluminium through utilization.Replacedly, the AZO layer can utilize the MOCVD method to form.AZO layer 110 can comprise from 5x10
19Cm
-3To 1x10
21Cm
-3The severe doping A1 material that changes.
Fig. 6 is the cross section SEM image with sputter AZO layer of directed cylinder form, and it shows the zinc oxide film that forms through sputter and is characterised in that the cylinder form.The orientation of column structure runs through the whole film thickness of about 600nm generally perpendicular to substrate.Aspect atomic structure; The zinc oxide (ZnO:Al) that zinc oxide (ZnO) perhaps is doped with aluminium is Wurzite structure (referring to the illustration among Fig. 7); It has element cell, and this element cell has in (100) plane the elongated c-axis perpendicular to zinc atom layer and oxygen atomic layer.Fig. 7 also shows the x-ray diffraction pattern with domination [002] summit, and it clearly indicates cylindrical orientation along the c-axis.For the ZnO or the AZO layer 110 that are formed on the intermediate layer 105, the c-axis normal is in first interface 107.Directed zinc oxide film demonstrates maximum piezoelectric effect, and this becomes favourable characteristic, and it can be used to the change that is caused by strain of the internal electric field in the controlling diaphragm.The illustration of Fig. 7 also shows the element cell that is in the zinc oxide under the pressure, and one is in compressive state and one and is in extended state.As shown in the figure, element cell only shrinks in (100) plane or expansion, and since the c-axis normal in the interface 107 and correspondingly extend or shrink along the c-axis direction.Therefore the misfit strain in ZnO or AZO layer is directly aimed at its atomic distance again and is changed its intrinsic piezoelectric property in element cell, makes that subsequently the internal electric field in the AZO layer produces the upper film that replaces and pass through second contact surface arrival such as the absorber layer that covers the AZO layer.
With reference to Fig. 5; In specific execution mode, the combination of the fermi level pinning at 107 places, first interface in the strain in the anode 110 (it is caused by the lattice mismatch between the intermediate layer 105 of anode layer 110 and below) and anode layer 110 and intermediate layer 105 makes second contact surface 112 places of internal electric field between anode 110 and absorber 115 reduce.In one embodiment, through the combined effect of stress and fermi level pinning, reduce across the intensity of the internal electric field E3 of second contact surface 107.In another embodiment, be reversed signal rotating its direction across the internal electric field E2 of second contact surface 107, rather than point to absorber towards anode.These greatly about-face tunnelling barrier arrive the AZO layer and/or directly help hole stream so that the hole is passed from absorber to improve the aggregation rate in hole through the rear electrode contact.As the result of combined effect, the photovoltaic cell of based thin film can have improved greatly photon-electronic switch efficient, and this conversion provides the efficient of solar energy module.
In interchangeable execution mode, the internal electric field of anode layer can change through near relevant Zn and the oxygen component the second contact surface in the change AZO layer.ZnO or ZnO:Al that sputter forms for example, when forming zinc oxide or specifically forming the AZO layer, can reduce or be increased in the oxygen content in the sputter working gas, so that can be rich zinc or oxygen enrichment.In atomic energy level, the Zn atom in the Zn atomic plane can be replaced by too much oxygen or alternate manner.This can change inherent strain, piezoelectric property, interfacial energy state and fermi level pinning and last internal electric field.
Although use specific execution mode to describe the present invention, it should be understood that under not departing from the situation that is limited to the spirit and scope of the present invention in the accompanying claims, can carry out multiple change, modification and modification to the method for using among the present invention.For example, the AZO layer being used for the back electric contacting layer is used as example and illustrates.Can use other transparent conductive layer to improve the photovoltaic conversion efficiency, said other transparent conductive layer can be in one way or the alternate manner adjustment assemble to change anode-absorber interface internal electric field and to change subsequently at the charge carrier at electric contact place, back.Because the essence of double side photovoltaic battery is importantly through one or more materials or structural parameter control interface internal electric field, to improve separation of charge and to improve charge carrier at the preceding electrode of battery and the collection efficiency at rear electrode place.In addition; Although above-mentioned execution mode be applied to process by CdTe or CIS and/or CIGS and by the AZO layer cover be used for the preceding of film lamination and after in the absorber that electrically contacts; Be benefited from this execution mode but the double-sided solar battery of other based thin film with single, two or more knots is also sure, and do not depart from the described invention of this paper claim.
Claims (20)
1. method that is used to form the two-side film membrane photovoltaic cell, said method comprises:
The glass substrate that has by intermediate layer covered surfaces zone is provided;
On said surf zone, form film photovoltaic cell; Said film photovoltaic cell comprises the anode that covers said intermediate layer, is positioned at the absorber of said anode top and window layer and the negative electrode that is positioned at said absorber top, has resilient coating between said window layer and negative electrode and the said absorber;
Wherein, Said anode comprises zinc oxide (AZO) layer that aluminium mixes forming first interface and to form second contact surface with said absorber with said intermediate layer, and said AZO layer is configured to cause said first at the interface fermi level pinning and the strain field from said first interface to said second contact surface.
2. method according to claim 1, wherein, said intermediate layer comprises film, said film is by the tin-oxide (TFO), indium tin oxide (ITO), the Si that mix from fluorine
3N
4, SiO
2, molybdenum, and their combination in the material selected process.
3. method according to claim 1, wherein, said absorber comprises the p-type semiconductor layer of being processed by CdTe material or copper indium gallium diselenide CIGS material.
4. method according to claim 1, wherein, said AZO layer comprises from 5x10
19Cm
-3To 1x10
21Cm
-3The A1 material that the severe that changes is mixed.
5. method according to claim 1, wherein, said first at the interface said fermi level pinning and the said strain field from said first interface to said second contact surface makes the internal electric field intensity of said second contact surface reduce.
6. method according to claim 5, wherein, the internal electric field intensity at said second contact surface place reduced to be used for barrier across the tunneled holes of said second contact surface from said absorber to said anode.
7. method according to claim 1, wherein, said first at the interface said fermi level pinning and the said strain field from said first interface to said second contact surface makes the internal electric field direction upset of said second contact surface.
8. method according to claim 7, wherein, the upset of the internal electric field direction at said second contact surface place directly helps the gathering in the hole of said second contact surface place from said absorber to said anode.
9. method according to claim 1, wherein, said substrate comprises receives lime glass.
10. method according to claim 1, wherein, said substrate comprises optional transparent material.
11. a utilization is used for the thin film solar device of the strain AZO layer at anode-absorber interface, said device comprises:
Optional transparency carrier;
Cover the intermediate layer of said transparency carrier;
Anode layer comprises zinc oxide (AZO) layer that forms the aluminium doping at first interface with said intermediate layer;
Absorber comprises the copper indium gallium diselenide with p-type dopant that forms second contact surface with said AZO layer;
Resilient coating, following is the window layer that covers said absorber after said resilient coating; And
Cathode layer covers said window layer;
Wherein, said AZO layer causes strain field and said first fermi level pinning at the interface in the said anode layer, is used to change the internal electric field at said second contact surface place.
12. device according to claim 11, wherein, said optional transparency carrier comprises receives lime glass.
13. device according to claim 11, wherein, said intermediate layer comprises film, and said film is by the tin-oxide (TFO), indium tin oxide (ITO), the Si that mix from fluorine
3N
4, SiO
2, molybdenum, and their combination in the material selected process.
14. device according to claim 11, wherein, said AZO layer comprises from 5x10
19Cm
-3To 1x10
21Cm
-3The A1 material that the severe that changes is mixed.
15. device according to claim 11; Wherein, Said strain field in the said anode layer and said first fermi level pinning at the interface makes the internal electric field intensity at said second contact surface place reduce, to be used to the promoting hole of passing through said anode layer from said absorber to assemble.
16. device according to claim 11; Wherein, Said strain field in the said anode layer and said first fermi level pinning at the interface makes the internal electric field direction at said second contact surface place overturn, to be used to the promoting hole of passing through said anode layer from said absorber to assemble.
17. device according to claim 11, wherein, said resilient coating comprises the cadmium sulfide with n-type dopant.
18. device according to claim 11, wherein, said window layer comprises transparent conductive oxide, and said transparent conductive oxide comprises the zinc oxide that aluminium mixes.
19. device according to claim 11, wherein, said cathode layer comprises the zinc oxide that severe aluminium mixes.
20. device according to claim 11, wherein, said absorber comprises the cadmium tellurides with p-type dopant.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US13/049,190 | 2011-03-16 | ||
| US13/049,190 US20110220198A1 (en) | 2010-03-31 | 2011-03-16 | Method and Device Utilizing Strained AZO Layer and Interfacial Fermi Level Pinning in Bifacial Thin Film PV Cells |
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| CN102683482A true CN102683482A (en) | 2012-09-19 |
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|---|---|---|---|---|
| US20020050289A1 (en) * | 2000-10-31 | 2002-05-02 | Kenji Wada | Solar cell substrate, thin-film solar cell, and multi-junction thin-film solar cell |
| US6951689B1 (en) * | 1998-01-21 | 2005-10-04 | Canon Kabushiki Kaisha | Substrate with transparent conductive layer, and photovoltaic element |
| US7235736B1 (en) * | 2006-03-18 | 2007-06-26 | Solyndra, Inc. | Monolithic integration of cylindrical solar cells |
| US20100258191A1 (en) * | 2009-04-13 | 2010-10-14 | Miasole | Method and apparatus for controllable sodium delivery for thin film photovoltaic materials |
| CN101908566A (en) * | 2009-06-02 | 2010-12-08 | 精工爱普生株式会社 | Solar cell and manufacture method thereof |
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2012
- 2012-03-14 TW TW101108612A patent/TW201246560A/en unknown
- 2012-03-16 CN CN2012100722140A patent/CN102683482A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6951689B1 (en) * | 1998-01-21 | 2005-10-04 | Canon Kabushiki Kaisha | Substrate with transparent conductive layer, and photovoltaic element |
| US20020050289A1 (en) * | 2000-10-31 | 2002-05-02 | Kenji Wada | Solar cell substrate, thin-film solar cell, and multi-junction thin-film solar cell |
| US7235736B1 (en) * | 2006-03-18 | 2007-06-26 | Solyndra, Inc. | Monolithic integration of cylindrical solar cells |
| US20100258191A1 (en) * | 2009-04-13 | 2010-10-14 | Miasole | Method and apparatus for controllable sodium delivery for thin film photovoltaic materials |
| CN101908566A (en) * | 2009-06-02 | 2010-12-08 | 精工爱普生株式会社 | Solar cell and manufacture method thereof |
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