CN103107214B - Nano dipoles solar cell and preparation method thereof - Google Patents

Nano dipoles solar cell and preparation method thereof Download PDF

Info

Publication number
CN103107214B
CN103107214B CN201110358135.1A CN201110358135A CN103107214B CN 103107214 B CN103107214 B CN 103107214B CN 201110358135 A CN201110358135 A CN 201110358135A CN 103107214 B CN103107214 B CN 103107214B
Authority
CN
China
Prior art keywords
nano
dipoles
electrode layer
conductive electrode
solar cell
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201110358135.1A
Other languages
Chinese (zh)
Other versions
CN103107214A (en
Inventor
刘向鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institute of Electrical Engineering of CAS
Original Assignee
Institute of Electrical Engineering of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institute of Electrical Engineering of CAS filed Critical Institute of Electrical Engineering of CAS
Priority to CN201110358135.1A priority Critical patent/CN103107214B/en
Publication of CN103107214A publication Critical patent/CN103107214A/en
Application granted granted Critical
Publication of CN103107214B publication Critical patent/CN103107214B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • Y02E10/543—Solar cells from Group II-VI materials
    • 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
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Photovoltaic Devices (AREA)

Abstract

A kind of nano dipoles solar cell, its photovoltaic effect layer (116) is made up of jointly the material and the nano dipoles particle be embedded in photovoltaic absorbing material with photovoltaic effect, and described nano dipoles particle has electric dipole moment or piezoelectric properties.The electric dipole moment of described nano dipoles particle is polarized and arrange in the same way at least partly, and nano dipoles polarize particles direction is important on the direction perpendicular to transparency conductive electrode layer or conductive electrode layer, and provides the macroscopic electric field be separated needed for photogenerated charge.Photovoltaic effect layer can generation current and voltage when receiving electromagenetic wave radiation.By obtaining required solar cell at the composite material of deposited on substrates N-shaped and p-type simultaneously.

Description

Nano dipoles solar cell and preparation method thereof
Technical field
The present invention relates to a kind of solar cell without planar junction electric field and preparation method thereof.
Background technology
Solar cell adopts the semi-conducting material at smooth interface to collect incident light energy and to generate electricity usually.Semi-conducting material is divided into two classes usually: electron rich material and n-type semiconductor and be rich in the p-type semiconductor of hole or depleted of electrons state.When solar cell is exposed under light source, the electron motion in n-layer is the generation current through the planar junction arrival p-type layer of semi-conducting material formation also.The generating capacity of solar cell is relevant with the surface area of p-n junction.The solar cell with single p-n junction may have larger surface area.Solar cell can adopt laminated construction to form many p-n junctions.In fact, multijunction solar cell stacks up to the single junction cell of specific band optical transparency.These multijunction cells may produce the power output identical or larger with single p-n junction battery.
Figure 1A and Figure 1B gives conventional p-n junctions type solar cell 10.Solar cell 10 has substrate layer 12, is used for supporting transparent conductive oxide (TCO) layer 14.Solar cell 10 comprises p-type semiconductor layer 16, n-type semiconductor layer 18, and the planar p-n junction 20 of routine.As shown in the direction of arrow of Figure 1B, the preparation process of solar cell 10 is, deposition tco layer 14 is on substrate layer 12, and then n-layer 18 (being made up of cadmium sulfide (CdS)) deposits on tco layer 14.P-type layer 16 (being made up of cadmium telluride (CdTe)) is deposited in n-layer 18, and p-n junction 20 contacts formation by n-layer 18 with the direct of p-type layer 16, has planar structure.Last metal conducting electrodes layer 22 deposits to preparation p-type layer 16 completing solar cell.As mentioned previously, p-type layer 16 and n-layer 18 are prepared respectively from different targets and obtain.Constructed p-n junction 20 be used for being formed electronics from p-type layer 16 to n-layer 18 and hole from n-layer 18 to the transmission of p-type layer 16 thus generating.
But the battery of every type has certain function limit.Single-junction photovoltaic cell may allow the light in very broadband to reach p-n junction, but is limited to selected materials, can not utilize all light reaching p-n junction.Many p-n junctions can utilize the light of specific band, but add up along with these are stacked, and every one deck all can stop that some to generate electricity useful light to lower floor.And each layer also needs to be " currents match ", ensureing the equal and opposite in direction of output current, because minimum output current is the factor that restriction battery always exports.Currents match equally by the selectional restriction of material on the material that those have close output.Along with the increase of the number of plies, the resistance in battery will cause extra parasitic loss and reduce battery efficiency.And the step preparing multijunction cell is complicated, too increases battery cost.Therefore, unijunction and multijunction solar cell meet each other half way always and improve battery efficiency and power output between battery size, flexibility, cost.
In prior art, the planar semiconductor layer preparation technology of solar cell is sequential and often walks relatively independent.Every one deck can realize with different process, e.g., and chemistry or physical vapour deposition (PVD) or sputtering.Usually one deck under then preparing on outermost metal conducting electrodes layer (as back electrode) or transparency conducting layer (as front window layer).Substrate is called as when being close to dorsum electrode layer " lower substrate ", is then called as " upper substrate ", depends on the relative ranks of each layer during use when substrate is close to front window layer.
Usually, different materials can be used to form each semiconductor layer.Such as, thin-film solar cells may have cadmium sulfide (CdS) n-layer and cadmium telluride (CdTe) p-type layer.Different source materials can be used to grow these layers in order.If sputter deposition craft, source material refers to target, by high energy particle (energetic ion as containing plasma) bombardment.The atom of material is shelled out and clashes into the battery layers surface prepared from target.Every one deck target used is all different.By changing target or selecting different target as sputter can realize preparing each layer semiconductor required in battery in single chamber.
But this preparation method can affect cost and the quality of solar cell.The deposition of every layer must be carried out in order, and deposition velocity is slow, causes throughput rate on the low side.If use single chamber, then changing target can increase technique and processing time and chamber may be made to be polluted.If sputter different targets according to process choice at different chambers, equipment and maintenance cost then can increase.In addition, single chamber prepares the output of battery limitation batch production solar cell.If use multi-chamber to realize high production capacity, namely pipeline system is produced, and significantly will increase equipment cost.Therefore, a kind of surface area can ideally be produced and thickness is all low and the solar cell that p-n junction surface area is large.
Compared with there is the photovoltaic device of p-n junction junction field structure, nano dipoles photovoltaic device can have following basic advantage in theory: 1) can realize symmetrical structure, substrate does not have difference lower with affecting battery efficiency in upper structure, be free to select transparent or opaque backing material, be also free to the backing material selecting rigidity or flexibility; 2) be expected to obtain higher output voltage; 3) one deck is only needed to be embedded with the material of nano dipoles, instead of such two-layer of p-n junction, greatly reduce equipment cost (estimating about half) and the production technology of film preparation; 4) between nano dipoles material and photovoltaic effect medium, do not need good electrical contact, therefore alternative photovoltaic medium and nano dipoles particle type many, the restriction by raw material supply is few.
Utilize the nano dipoles preparation method of solar battery of this invention, the conversion efficiency of thin-film solar cells, uniformity and yield rate can be promoted further, there is great diversity.The preparation method of this nano dipoles solar cell can produce on existing CdTe thin film manufacture of solar cells line, can reduce expensive vacuum equipment cost.
The technology of dipole antenna array battery of the prior art, such as JournalofSolarEnergyEngineering2010 to perm February 132 table " TheoryandManufacturingProcessesofSolarNanoantennaElectro magneticCollectors " literary composition described by.Its principle produces alternating current by the dipoles scatter sub antenna of array arrangement to electromagnetic induction to produce absorption to solar energy, but the biggest problem that current this technology runs into is 10 13-10 16the high-frequency rectification diode of Hz (visible light wave range) does not also exist, and therefore this battery reality does not also realize.Further, dipole antenna array battery absorbs solar photon by dipole, and nano dipoles aerial array battery is that technology makes slowly by costlinesses such as electron beam micro-nano technology, X-ray lithographies, and cost of manufacture is very high.
The preparation method of current solar cell at least needs two kinds of remarkable different compositions to form enough strong p-n junction electric field, requires to keep excellent electric contact between them simultaneously.This essential disadvantages of prior art result in and must often deposit respectively in order by layer material in production solar cell process.If at single vacuum chamber deposition different materials, then may cross pollution be produced, and limit the speed of production of solar cell.If sputter different targets according at different chambers, equipment and maintenance cost then can increase.
Summary of the invention
The object of the invention is the above-mentioned shortcoming overcoming prior art, propose a kind of solar cell and preparation method thereof, and the macro property of solar cell described in quantization signifying and the method for relation between its microstructure and polarization characteristic.The surface area of solar cell of the present invention and thickness are all lower, and p-n junction surface area ratio is larger.
The structure of solar cell of the present invention is:
Described solar cell comprises substrate layer, the first transparency conductive electrode layer, photovoltaic effect layer and the second conductive electrode layer, and wherein the second conductive electrode layer is made by transparent material or opaque material.The order that the position relationship of described each layer enters with sunlight arranges, and is followed successively by the first transparency conductive electrode layer, photovoltaic effect layer and the second conductive electrode layer.When substrate layer be made into by transparent material time, as glass or transparent organopolysiloxane film, before substrate layer can be positioned at the first transparency conductive electrode layer; When substrate layer is made up of opaque material, as thin aluminium foil, molybdenum foil, stainless steel substrates, after substrate layer must be positioned at the second conductive electrode layer.
Described photovoltaic effect layer is made up of jointly the material and the nano dipoles particle be embedded in photovoltaic effect material with photovoltaic effect, and described nano dipoles particle has polarization or piezoelectric properties.
Be with the structural similarity part of traditional p-n junction battery or similar junction field battery, the present invention is made up of photovoltaic effect layer and two conductive layers.With p-n junction battery or similar junction field battery unlike, the photovoltaic effect layer of battery of the present invention only has independent one deck, and traditional p-n junction battery needs at least each one deck of p-type layer and n-layer.And, the photovoltaic effect layer of nano dipoles battery of the present invention is jointly made up of the nano dipoles particle of the material and wherein patchiness with photovoltaic effect, can form internal electric field when the electric dipole moment of described nano dipoles particle (as nano particle) arranges in the same way; When the direction that electric dipole moment arranges in the same way is important on the direction perpendicular to transparency conductive electrode layer or conductive electrode layer, will generation current and voltage under electromagnetic radiation; First transparency conductive electrode layer allows photon to pass through, and produces photo-generated carrier after photon is absorbed by photovoltaic effect layer; A kind of photo-generated carrier simultaneously produced by the first transparency conductive electrode layer collection photovoltaics effect layer, the second conductive electrode layer collects another kind of photo-generated carrier; Substrate layer provides mechanical support for solar cell of the present invention.
The first described transparency conductive electrode layer can allow the electromagnetic wave of certain wave band penetrate and have electrical conductance.Permeable electromagnetic radiation is the light that a kind of wavelength is less than 1100nm, comprises near-infrared, visible ray and ultraviolet light.
Described photovoltaic effect layer contacts with the first transparency conductive electrode layer, for absorbing the electromagnetic wave of a part by the first transparency conductive electrode layer.Photovoltaic effect layer includes nano dipoles particle, and described nano dipoles particle can be the one in p-type or n-type semiconductor, and photovoltaic dielectric material is the another kind in p-type or N-shaped material.Such as the present invention uses the CdS of the CdS of N-shaped or rich S xte (1-x)the nano particle that alloy is formed, photovoltaic medium is made up of the CdTe photovoltaic dielectric material of p-type.There is the CdS-CdTe alloy transition district of gradual change from nano particle to CdTe photovoltaic medium, alloy has higher S composition near nano dipoles particle, has higher Te composition near CdTe photovoltaic proximate dielectric.The transition region of CdS-CdTe alloy is described as CdS xte (1-x), wherein, what x characterized is the relative components of sulphur and tellurium, and x=0 represents not sulfur-bearing, and x=1 represents not containing tellurium.The each CdS nano particle be embedded in photovoltaic layer of dielectric material produces an electric dipole with electric dipole moment, and forms the electric field relevant to electric dipole.The formation of electric dipole is because the ion of a surface enrichment positively charged of nano particle, as cadmium Cd atom, at the relative electronegative ion of another side enrichment, as sulphur S atom.Relatively arranging in the same way appears in electric dipole at least partly, and polarised direction court is perpendicular to TCO or conductive electrode layer.Such as, Cd atom in CdS electric dipole is usually towards in TCO or conductive electrode layer, and S atom is usually towards another in TCO or conductive electrode layer.
The second described conductive electrode layer can be and the first transparency conductive electrode layer same or similar transparent conductive oxide (TCO) material, can be also opaque electric conducting material, as metal, graphite etc.The second described conductive electrode layer is used for the positive and negative polarities forming solar cell with the first transparency conductive electrode layer, can connect load, exports electric current and the voltage of battery generation.
The preparation method of solar cell of the present invention can the mixture of depositing n-type material and p-type material on the backing material covering transparency conductive electrode layer simultaneously, and a step makes the photovoltaic effect layer of solar cell.
Preparation method of solar battery of the present invention specifically describes as follows:
First prepare the mixed film of N-shaped material and p-type material, then by (PhaseSegregation) characteristic that is separated of bi-material in high-temperature heat treatment process, isolate N-shaped material and p-type material.When N-shaped material has dipolar nature, the method just can be formed in p-type material the numerous molecules inlaying the N-shaped material formation with dipole moment; When p-type material has dipolar nature, the numerous molecules inlaying the p-type material formation with dipole moment just can be formed in N-shaped material.
For p-type CdTe photovoltaic effect material and N-shaped CdS piezoelectric, the concrete preparation method that the present invention forms the molecule with electric dipole moment in photovoltaic film is: the target using cadmium sulfide CdS and cadmium telluride CdTe bi-material mixing compacting, described target in CdS:CdTe mass ratio be between 1:2.5 to 1:30 ratio mixing after, at 1000 to 10000N/cm 2pressure under compacting form target; Adopt the method for vacuum sputtering, there is transparent conductive oxide (TCO) conductive layer, be i.e. the glass substrate of the second conductive electrode layer deposits CdSTe alloy firm; And through heat treatment, heat-treatment temperature range is 350 DEG C to 650 DEG C, is incubated 10 – 120 minutes, makes CdSTe alloy be separated at a certain temperature, as shown in Figure 4, in CdSTe film, form the molecule being rich in CdS.
Described cadmium sulfide CdS is a kind of piezoelectric, its molecule has obvious electric dipole moment, in its forming process, can nature be arranged in roughly consistent, perpendicular to transparent conductive oxide (TCO) conductive layer, i.e. the direction on the first transparency conductive electrode layer surface.This roughly consistent arrangement in the same way also constitutes the internal electric field of alternative p-n junction perpendicular to the macroscopic electric field that the electric dipole of electrode layer is formed.
Preparation method of the present invention is similar to traditional C dS/CdTe hull cell, uses vacuum deposition method, can directly realize in conventional equipment.But conventional method needs to prepare at least double-layer films (i.e. N-shaped CdS and p-type CdTe layer) realizes photovoltaic effect, and the present invention only need prepare one deck CdSTe film just can realize photovoltaic effect.
Present invention utilizes this semi-conducting material with piezoelectric properties of CdS.CdS is the same with other II-VI group material have significantly ionic.Its most stable crystal structure is wurtzite structure, belongs to hexagonal crystal system, does not have a mirror symmetry.Therefore, because the asymmetric CdS of the making crystal of the distribution of Cd with S ion can form positive elecrtonegativity respectively on relative two sides and with electric dipole moment.The CdS particle of nano-scale with dipole moment, can arrange roughly in the same way under electric field force outside, and still retain certain electric polarity, i.e. so-called ferroelectric effect after outfield is eliminated.
The present invention prepares one of preparation method of described nano dipoles solar cell and comprises following steps:
A) the clean glass substrate being coated with the first described transparency conductive electrode layer, then the mixed film of sputtering sedimentation CdTe and CdS in described glass substrate, described film thickness scope is 0.2-20 μm, and the target of use is CdS and CdTe compacting after the mixing of 1:30-1:2.5 scope in mass ratio;
B) glass substrate that deposited CdTe and CdS mixed film is placed in CdCl 2with heat treatment in the mixed-gas atmosphere of air, heating-up temperature is 350 ~ 650 DEG C, temperature retention time 5-120 minutes;
C) at CdCl 2film surface after heat treatment re-uses the second conductive electrode layer described in sputtering method deposition, the solar cell described in formation.
Implement described in step a) and step b) while, the first described transparency conductive electrode layer applies polarized electric field, and voltage is 10 ~ 3000V, and deposited CdTe and CdS mixed film is placed among electric field.
The present invention prepares the preparation method's of described nano dipoles solar cell two and comprises following steps:
A) the clean glass substrate being coated with the second described conductive electrode layer, then sputtering sedimentation CdTe and CdS mixed film in described glass substrate, described film thickness scope is 0.2-20 μm, and the target of use presses compacting after 1:30-1:2.5 (mass ratio) mixing for CdS and CdTe;
B) glass substrate that deposited CdTe and CdS mixed film is placed in CdCl 2heat treatment in the mist of steam and air, heat treatment temperature is 350 ~ 650 DEG C, and temperature retention time is 5-120 minutes;
C) in step b) CdCl 2film surface after heat treatment deposits the first transparency conductive electrode layer again, forms complete solar cell.
While the step described in implementing a) and b), the first described transparency conductive electrode layer applies polarized electric field, and voltage is 10 ~ 3000V, and deposited CdTe and CdS mixed film is placed among electric field.
The present invention drives the nano dipoles with dipole moment to arrange the method forming macroscopical internal electric field in the same way and has two kinds:
1) because CdSTe alloy firm has been deposited on the first transparency conductive electrode layer or the second conductive electrode layer before heat treatment, in heat treatment process, the image force effect of this two-layer conductive electrode layer can be utilized, arrange in the same way in the direction of described conductive electrode layer at the granuloplastic nano dipoles particles at right angles that drives of nano dipoles simultaneously;
2) can after CdSTe alloy firm, deposit one deck conductive electrode layer again or cover layer of conductive material non-contiguously, between described conductive electrode layer and this layer of conductive electrode layer deposited again after CdSTe alloy firm or conductive material layer, apply the applied direct current bias electric field of 10 ~ 3000V, drive the arrangement in the same way of nano dipoles.Both the image force of TCO and extra electric field can have been utilized in CdSTe alloy firm deposition process to drive the arrangement in the same way of nano dipoles, also can after CdSTe alloy firm deposition, utilize the image force of TCO and extra electric field to drive the arrangement in the same way of nano dipoles.The method forming electric dipole macroscopic view internal electric field is versatile and flexible, can do necessary adjustment, can realize same object in conjunction with different apparatus and process.
The first transparency conductive electrode layer that the present invention uses can be the zinc oxide (ZnO:Al mixing aluminium 2o 3or AZO), tin indium oxide (ITO), mix the tin oxide (SnO of fluorine 2: F or FTO) etc., the method for sputtering or chemical vapour deposition (CVD) (CVD) can be used to make.Second conductive electrode layer both can be transparent conductive oxide also can be opaque metal, graphite etc., and the conductive electrode layer such as metal, graphite then can adopt sputtering or electric plating method preparation.
The present invention also proposes a kind of method verifying nano dipoles particle solar cell of the present invention, and this method utilizes the piezoelectric effect of the piezoelectric forces microscopy checking nano dipoles based on piezoelectric forces microscope (PFM) principle.The innovation of this method is to contact directly setting up between the piezoelectric property of nano dipoles particle and the conversion efficiency of nano dipoles particle solar cell, for solar cell of the present invention process modification, improve macro property effect and provide microcosmic and direct foundation.
The present invention is by the macro property of piezoelectric forces microscope (PiezoresponseForceMicroscopy) quantization signifying nano particle solar cell and relation between its microstructure and polarization characteristic, by longitudinal piezoelectric effect (VerticalPFM) and the piezo-electric traverse effect (LateralPFM) of scanning survey solar cell of the present invention, evidence and the distributed intelligence of nano dipoles existence are found in scanning, are obtained the information of the local polarisation directional spreding of electric dipole by vectorial piezoelectric effect (VectorPFM) scanning simultaneously.Under contact mode, a concussion voltage is applied to film surface by the microscopical conducting probe of piezoelectric forces, piezoelectric property due to electric dipole particle can produce the deformation concussion of same frequency under the impact of this local biases, does not have the other materials of piezoelectric property then can not change.Coordinate the position of piezoelectric forces microscope conducting probe, just can draw out the distribution of nano dipoles particle.The longitudinal oscillation of probe can be caused when nano dipoles particle stretches, produce longitudinal piezoelectric effect figure; Probe teeter can be caused during the tangential deformation of nano dipoles particle, and produce piezo-electric traverse effect figure.The Oscillation Amplitude of nano dipoles particle is then directly proportional to polar intensity.And the polarised direction of nano dipoles particle and applying bias field direction inconsistent time, the phase place of deformation has and relatively lags behind, therefore this phase difference can provide the information of electric dipole polarised direction, and the information of electric dipole polarised direction is called vectorial piezoelectric effect figure.
More detailed data can be obtained by scanning film surface and cross section two kinds of modes.Because piezoelectric forces microscope is a kind of atomic force microscopy system installing conducting probe, resolution can reach nanometer scale, directly and accurately can obtain the information that electric dipole polarized electric field distributes, this will be the direct verification method proving that CdS nano dipoles exists in the devices.Make the information such as size, distribution, local polarisation direction and intensity intuitively can drawing out electric dipole particle in semiconductive thin film in this way, for the optimization of nano dipoles particle solar cell properties provides foundation.
Accompanying drawing explanation
Figure 1A routine has the solar cell cross-sectional structure figure of planar p-n junction;
Figure 1B routine has preparation method's schematic diagram of planar p-n junction solar cell;
The solar battery structure schematic diagram of Fig. 2 A upper substrate of the present invention;
Solar battery structure schematic diagram during Fig. 2 B lower substrate of the present invention;
Preparation method's schematic diagram of Fig. 2 C solar cell of the present invention;
The enlarged cross sectional views of the nano dipoles particle that Fig. 3 solar cell of the present invention is inlayed in photovoltaic medium;
Fig. 4 relative components figure of tellurium and sulphur under different temperatures in cadmium-tellurium-sulphur alloy, x is the relative amount of sulphur;
Fig. 5 A nano dipoles particle enlarged drawing, has marked S and Cd;
The film blank layer schematic diagram of formation nano particle solar cell prepared by Fig. 5 B the present invention, gives relatively chaotic electric dipole orientation in figure;
Fig. 5 C nano particle solar cell schematic diagram, gives relatively consistent electric dipole orientation in figure;
Fig. 5 D the present invention another kind of nano particle solar battery structure schematic diagram, gives the electric dipole orientation of high consistency in figure;
The incident electromagnetic wave wavelength of the different solar cell of Fig. 6 and external quantum efficiency graph of a relation;
The transformation efficiency of Fig. 7 A nano particle solar cell and CdCl 2the box of processing time relation must be schemed;
The transformation efficiency of the planar junction battery of Fig. 7 B common process and CdCl 2the box of processing time relation must be schemed;
The open circuit voltage of Fig. 8 A nano particle solar cell and CdCl 2the box of processing time relation must be schemed;
The open circuit voltage of the planar junction battery of Fig. 8 B common process and CdCl 2the box of processing time relation must be schemed;
The short circuit current of Fig. 9 A nano particle solar cell and CdCl 2the box of processing time relation must be schemed;
The short circuit current of the planar junction battery of Fig. 9 B common process and CdCl 2the box of processing time relation must be schemed;
The absorption coefficient of the various film of Figure 10 and the square value [(α * hv) of the product of corresponding energy hv 2] with the graph of a relation of band gap, compare the different of common process planar junction battery and nano particle solar cell;
The current-voltage curve of the CdS nano dipoles solar cell that Figure 11 uses the present invention to prepare;
Figure 12 A, Figure 12 B adopt the schematic diagram of piezoelectric forces microscope checking nano dipoles solar cell.
Embodiment
The present invention is further illustrated below in conjunction with the drawings and the specific embodiments.
As shown in Figure 2 A, the position relationship of each layer of solar cell 100 described in composition puts in order and is followed successively by the structure of solar cell 100 of the present invention from inside to outside: substrate layer 112, first transparency conductive electrode layer 118, photovoltaic effect layer 116 containing nano dipoles particle and the second conductive electrode layer 114.After substrate layer 112 also can be positioned at the second conductive electrode layer 114, other each layer invariant positions, as shown in Figure 2 B.
Described substrate layer 112 is made up of transparent material, and such as, glass, polyimide-based polymer film also can be opaque metal levels, such as, and thin aluminium foil, molybdenum foil, stainless steel substrates.When substrate layer 112 is made up of transparent material, substrate layer 112 first deposits the first transparency conductive electrode layer 118, more successively depositing photovoltaic effect layer 116 and the second conductive electrode layer 114, as shown in Figure 2 A.During use, electromagnetic wave, as visible ray, by transparent substrate layer 112 and the first transparency conductive electrode layer 118, enters photovoltaic effect layer 116.When substrate layer 112 is made up of opaque material, then need first the second conductive electrode layer 114 to be deposited on substrate layer 112, more successively depositing photovoltaic effect layer 116 and the first transparency conductive electrode layer 118, as shown in Figure 2 B.And in use, electromagnetic wave need from the first transparency conductive electrode layer 118 through entering photovoltaic effect layer 116.
Described photovoltaic effect layer 116 is made up of jointly the material and the nano dipoles particle be embedded in photovoltaic effect material with photovoltaic effect, and described nano dipoles particle has polarization or piezoelectric properties.
First transparency conductive electrode layer 114 is transparent conductive oxides, e.g., and the zinc oxide (ZnO:Al of alumina doped 2o 3or AZO), tin indium oxide (ITO), mix the tin oxide (SnO of fluorine 2: F or FTO) etc.Therefore electromagnetic wave also can arrive adjacent lower one deck photovoltaic effect layer 116 by this layer.Adjacent lower one deck photovoltaic effect layer 116 can convert sunlight to electric energy.Described photovoltaic effect layer 116 is deposited between the first transparency conductive electrode layer 114 and the second conductive electrode layer 118.Photovoltaic effect layer 116 comprises p-type photovoltaic medium 122 and is included in wherein and the N-shaped nano particle 120 be in contact with it.N-shaped nano particle 120 can partially or completely be embedded in p-type photovoltaic medium 122, as shown in Figure 2 A.N-shaped nano-particle material can be any semi-conducting material that can be used for preparing n-layer in planar junction solar cell, such as, and CdS.
In the nano particle solar battery structure of another kind of form, the nano particle in photovoltaic effect layer also can be p-type.P-type nano particle can be partially or completely be embedded in photovoltaic dielectric material.P-type nano particle can be any material that can be used for being formed planar junction solar cell p-type layer.Such as, p-type nano particle can be ZnTe:N, or other material and material/doping combination.ZnTe material can realize the doping to ZnTe by introducing nitrogen in sputtering technology.Nitrogen is introduced in ZnTe material lattice and forms ZnTe:N as p-type particle.
Figure 3 shows that the structure be exaggerated of photovoltaic effect layer 116 in Fig. 2 A.Nano particle 120 represents with N-shaped CdS nano particle.P-type photovoltaic medium 122 is CdTe layer.Transition region 126 is present between N-shaped nano particle 120 and p-type photovoltaic medium 122.In a kind of non-limitative example of photovoltaic effect layer 116, transition region 126 is made up of cadmium, sulphur and tellurium alloy.In a kind of version of nano particle solar cell 100, transition region 126 is characterized as being CdS (x)te (1-x), wherein x represents CdS (x)te (1-x)the relative components of sulphur and tellurium in alloy, the span of x is in the scope between 0 to 1, and x=0 represents not sulfur-bearing, and x=1 represents not containing tellurium.
Described transition region 126 is a kind of CdS (x)te (1-x)alloy is from rich tellurium region to the gradual change in rich sulphur region.At the point closest to nano particle electric dipole CdS120, x is 1.Along with distance increases to photovoltaic medium 122 gradually from nano particle 120, the value of x gradually becomes 0.Therefore, move along with to photovoltaic medium, element T e replaces S gradually and combines with Cd.
In another kind of non-limitative example, x also can represent the distance from one end of transition region 126 to the other end, from photovoltaic medium 122 to nano particle 120.Such as, at CdS (x)te (1-x)in x can the distance of Linear proportional in from photovoltaic medium 122 to nano particle 120.
As shown in Figure 2 C, in the method preparing nano particle solar cell 100 of the present invention, by suitable depositing operation, as sputtering, on the first transparency conductive electrode layer, form photovoltaic effect layer.
Sputtering forms the first step of nano dipoles particle solar cell 100 method, need provide target 124.Contained by target 124, material has suitable ingredients, to form photovoltaic effect layer.Target 124 can be the mixture of alloy or metallic compound or simple substance, as CdTe and CdS mixing, or simple substance Cd, S and Te mixing.Target 124 can comprise any compound or element simple substance, such as CdTe photovoltaic dielectric material and the CdS that are used for being formed photovoltaic effect layer.Target 124 can be by granulate mixture, and as the material used in powder metallurgical technique 5, or the solid alloy material compacting of required component forms.
The present invention prepares one of preparation method of described nano dipoles solar cell and comprises following steps:
A) the clean glass substrate being coated with the first described transparency conductive electrode layer, then the mixed film of sputtering sedimentation CdTe and CdS in described glass substrate, described film thickness scope is 0.2-20 μm, and the target of use is CdS and CdTe compacting after the mixing of 1:30-1:2.5 scope in mass ratio;
B) glass substrate that deposited CdTe and CdS mixed film is placed in CdCl 2with heat treatment in the mixed-gas atmosphere of air 5-120 minutes, heating-up temperature was 350 ~ 650 DEG C;
C) at CdCl 2film surface after heat treatment re-uses the second conductive electrode layer described in sputtering method deposition, the solar cell described in formation.
While the step described in implementing a) and b), the first described transparency conductive electrode layer applies polarized electric field, and voltage is 10 ~ 3000V, and deposited CdTe and CdS mixed film is placed among electric field.
The present invention prepares the preparation method's of described nano dipoles solar cell two and comprises following steps:
A) the clean glass substrate being coated with the second described conductive electrode layer, then sputtering sedimentation CdTe and CdS mixed film in described glass substrate, described film thickness scope is 0.2-20 μm, and the target of use presses compacting after 1:30-1:2.5 (mass ratio) mixing for CdS and CdTe;
B) mixed film that deposited CdTe and CdS is placed in CdCl 2heat treatment in the mist of steam and air; Heat treatment temperature is 350 ~ 650 DEG C, and temperature retention time is 5-120 minutes;
C) in step b) CdCl 2film surface after heat treatment deposits the first transparency conductive electrode layer again, forms complete solar cell.
While the step described in implementing a) and b), the first described transparency conductive electrode layer applies polarized electric field, and voltage is 10 ~ 3000V, and deposited CdTe and CdS mixed film is placed among electric field.
It is below the embodiment of the solar cell described in preparation.
Embodiment 1
First high-purity ZnO:Al target of 99.999% is installed on the target position of magnetron sputtering apparatus; Then clean glass substrate is sent into the vacuum chamber of thermal evaporation apparatus, and be heated to 200 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between target and glass substrate is 10cm; The ZnO:Al transparent conductive film (TCO) that sputtering sedimentation 1.0 μm is thick under these process conditions, i.e. the first transparency conductive electrode layer.
Again by CdS and CdTe in mass ratio 1:30 ratio mixing, at 6000N/cm 2pressure under be pressed into hybrid target material, this target of making of mixing target is installed on the target position of magnetron sputtering apparatus.Then the glass substrate depositing the first transparency conductive electrode layer is sent in the vacuum chamber of magnetron sputtering apparatus, be heated to 250 DEG C.Vacuum chamber is evacuated to lower than 4 × 10 -4pa.Argon gas is filled with to 2Pa in vacuum chamber.Open radio frequency sputtering power supply, regulate its power output to 2.5W/cm 2.Distance between target and glass substrate is 10cm.The CdSTe alloy firm that sputtering sedimentation 0.2 μm is thick under these process conditions, makes the solar battery thin film base Rotating fields be made up of substrate, the first transparency conductive electrode layer and photovoltaic effect layer, as 150 in Fig. 5 B.
As shown in Figure 5A, CdS electric dipole nano particle 200 is cadmium sulfide molecules of a polarization, has electric field 210 between positive pole 212 and negative pole 214.N-shaped CdS nano particle 120 can be formed by one or more CdS electric dipole molecule 200.There is electric dipole moment between positive pole 212 and negative pole 214, its direction as shown by arrow A.Described solar battery thin film base layer 150 comprises many CdS nano particles 120.
Described solar battery thin film base Rotating fields 150 is taken out from sputtering vacuum chamber.Fig. 5 C gives electric dipole through CdCl 2arrangement in the same way after heat treatment, wherein electric dipole arrangement also can be rightabout, and this depends on the cohesion forming process of nano dipoles particle and the control of heating-up temperature.As shown in Figure 5 C, nano dipoles particle solar battery thin film base Rotating fields 150 is placed in CdCl 2in heat-treat by Technology for Heating Processing 160, namely containing CdCl 2be heated to 350 DEG C in the mist of saturated steam and dry air, and be incubated 120 minutes, thus the nano particle solar cell 150 ' that forming section arranges in the same way.CdS electric dipole 200 is at CdCl 2react in treatment process 160, to such an extent as to the electric dipole moment of each nano particle 120 is arranged with substantially identical direction.As shown in Figure 5 C, the common direction of nano particle 120 is away from the first transparency conductive electrode layer 114.The in the same way arrangement of CdS electric dipole 200 in p-type photovoltaic medium 122 improves power stage and battery efficiency.Complete the CdCl as 160 or 170 2after heat treatment, cool to room temperature.
Then by CdCl 2nano dipoles particle solar battery thin film base Rotating fields after heat treatment sends into the vacuum chamber of this sputtering equipment, puts into the High Purity Gold of 99.99% in evaporator crucible; Vacuumize and reach lower than 4 × 10 -4pa; Opening heating power supply powers until gold dissolves to evaporator crucible; Open baffle plate to glass substrate hydatogenesis gold, thickness is 600nm, prepares the second conductive electrode layer, completes described solar cell preparation.
Embodiment 2
High-purity ZnO:Al target of 99.999% is installed on the target position of magnetron sputtering apparatus; Then clean glass substrate is sent into the vacuum chamber of thermal evaporation apparatus, and be heated to 200 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between target and glass substrate is 10cm; The ZnO:Al transparent conductive film (TCO) that sputtering sedimentation 1.0 μm is thick under these process conditions, i.e. the first transparency conductive electrode layer.
By ZnTe and CdTe in mass ratio 1:30 ratio mixing after, at 10000N/cm 2pressure under be pressed into hybrid target material, this target of being pressed into of mixing target is installed on the target position of magnetron sputtering apparatus.Then TCO Conducting Glass is sent in the vacuum chamber of this sputtering equipment, and be heated to 250 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon Ar and nitrogen N is filled with in vacuum chamber 2mist to 2Pa, the volume ratio of mist is Ar:N 2=97:3; Open radio frequency sputtering power supply, regulate the power output of this power supply to 2.5W/cm 2.Distance between target and glass substrate is 10cm.The CdZnTe:N alloy firm that sputtering sedimentation 2.0 μm is thick under these process conditions, makes nano dipoles particle solar battery thin film base Rotating fields 150.
The TCO thin film of nano dipoles particle solar battery thin film base Rotating fields 150 is added the direct voltage of 1000V, and base Rotating fields is exposed to CdCl 2be heated to 650 DEG C in the mist of steam and dry air, and be incubated 10 minutes, then cool to room temperature.Due to ZnTe more easily formed high concentration of p-type doping and CdTe substantially not by the characteristic that N doping affects, in CdTe photovoltaic medium, form the heavily p-type ZnTe:N nano dipoles particle of N doping.
Then by CdCl 2nano dipoles particle solar battery thin film base Rotating fields after heat treatment sends into the vacuum chamber of this sputtering equipment, puts into the High Purity Gold of 99.99% in evaporator crucible; Vacuumize and reach lower than 4 × 10 -4pa; Opening heating power supply powers until gold dissolves to evaporator crucible; Open baffle plate to glass substrate hydatogenesis gold, thickness is 600nm, prepares the second conductive electrode layer, completes battery preparation.
Embodiment 3
High-purity ZnO:Al target of 99.999% is installed on the target position of magnetron sputtering apparatus; Then clean glass substrate is sent into the vacuum chamber of thermal evaporation apparatus, and be heated to 200 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between target and glass substrate is 10cm; The ZnO:Al transparent conductive film (TCO) that sputtering sedimentation 1.0 μm is thick under these process conditions, i.e. the first transparency conductive electrode layer.
By CdS and CdTe in mass ratio 1:20 ratio mixing after, at 1000N/cm 2pressure under be pressed into hybrid target material, the target that this composite material is made is installed on the target position of magnetron sputtering apparatus; Then TCO Conducting Glass is sent into the vacuum chamber of this sputtering equipment, and be heated to 250 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between target and glass substrate is 10cm; The CdSTe alloy firm that sputtering sedimentation 5 μm is thick under these process conditions, makes nano dipoles particle solar battery thin film base Rotating fields 150.
Nano dipoles particle solar battery thin film base Rotating fields 150 is placed in CdCl 2dry air in be heated to 650 DEG C, and be incubated 5 minutes, then cool to room temperature.
Then by CdCl 2nano dipoles particle solar battery thin film base Rotating fields after heat treatment sends into the vacuum chamber of this sputtering equipment, puts into the High Purity Gold of 99.99% in evaporator crucible; Vacuumize and reach lower than 4 × 10 -4pa; Opening heating power supply powers until gold dissolves to evaporator crucible; Open baffle plate to glass substrate hydatogenesis gold, thickness is 600nm, prepares the second conductive electrode layer, completes battery preparation.
Embodiment 4
Clean glass substrate is sent into the vacuum chamber of thermal evaporation apparatus, in evaporator crucible, put into the High Purity Gold of 99.99%; Vacuumize and reach lower than 4 × 10 -4pa; Opening heating power supply powers until gold dissolves to evaporator crucible; Open baffle plate to glass substrate hydatogenesis gold, thickness is 600nm.Complete the preparation of the second conductive electrode layer.
By CdS and CdTe in mass ratio 1:20 ratio mixing after, at 1000N/cm 2pressure under be pressed into hybrid target material, the target that this composite material is made is installed on the target position of magnetron sputtering apparatus; Then the glass substrate having deposited gold thin film is sent into the vacuum chamber of this sputtering equipment, and be heated to 250 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between target and glass substrate is 10cm; The CdSTe alloy firm that sputtering sedimentation 2.0 μm is thick under these process conditions, makes nano dipoles particle solar battery thin film base Rotating fields.
Second conductive electrode layer-the gold thin film of the nano dipoles particle solar battery thin film base Rotating fields be made up of substrate, the second conductive electrode layer and photovoltaic effect layer is added the direct voltage of 10V, and base Rotating fields is placed in CdCl 2dry air in be heated to 550 DEG C, and be incubated 90 minutes, then cool to room temperature.
Complete CdCl 2after heat treatment, prepare the first transparency conductive electrode layer on the solar cell, complete battery preparation.High-purity ZnO:Al target of 99.999% is installed on the target position of magnetron sputtering apparatus; Then by CdCl 2nano dipoles particle solar battery thin film base Rotating fields after heat treatment sends into the vacuum chamber of this sputtering equipment, and is heated to 200 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between target and glass substrate is 10cm; The ZnO:Al transparent conductive film that sputtering sedimentation 1.0 μm is thick under these process conditions, makes nano dipoles particle solar cell.
Embodiment 5
High-purity ZnO:Al target of 99.999% is installed on the target position of magnetron sputtering apparatus; Then will send into the vacuum chamber of this sputtering equipment at the bottom of clean stainless steel lining, and be heated to 400 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between at the bottom of target and stainless steel lining is 10cm; The ZnO:Al transparent conductive film (TCO) that sputtering sedimentation 1.0 μm is thick under these process conditions, i.e. the first transparency conductive electrode layer.
By CdS and CdTe in mass ratio 1:20 ratio mixing after, at 1000N/cm 2pressure under be pressed into hybrid target material, the target that this composite material is made is installed on the target position of magnetron sputtering apparatus; Then will at the bottom of the stainless steel lining having deposited ZnO:Al, send into the vacuum chamber of this sputtering equipment, and be heated to 300 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between at the bottom of target and stainless steel lining is 10cm; The CdSTe alloy firm that sputtering sedimentation 20 μm is thick under these process conditions, makes nano dipoles particle solar battery thin film base Rotating fields.
Nano dipoles particle solar battery thin film base Rotating fields is placed in CdCl 2dry air in be heated to 650 DEG C, and be incubated 5 minutes, then cool to room temperature.
Then by CdCl 2nano dipoles particle solar battery thin film base Rotating fields after heat treatment sends into the vacuum chamber installing the sputtering equipment of high-purity ZnO:Al target of 99.999%, and is heated to 400 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate this output power of power supply to 2.5W/cm 2, the distance between at the bottom of target and stainless steel lining is 10cm; The ZnO:Al transparent conductive film that sputtering sedimentation 1.0 μm is thick under these process conditions, opaque substrate is made nano dipoles particle solar cell.
Embodiment 6
First nano dipoles particle solar battery thin film base Rotating fields 150 is prepared.By CdS and CdTe in mass ratio 1:2.5 ratio mixing after, at 6000N/cm 2pressure under be pressed into hybrid target material, the target that this composite material is made is installed on the sputtering target position of magnetron sputtering apparatus; Then the glass substrate (TCO glass) being coated with the first transparency conductive electrode layer is sent into the vacuum chamber of this sputtering equipment, and be heated to 250 DEG C; To vacuum chamber extremely lower than 4 × 10 -4pa; Argon gas is filled with to 2Pa in vacuum chamber; Open radio frequency sputtering power supply, regulate its power output to 2.5W/cm 2, the distance between target and glass substrate is 10cm; The CdSTe alloy firm that sputtering sedimentation 20 μm is thick under these process conditions, makes nano dipoles particle solar battery thin film base Rotating fields 150.
Fig. 5 D gives the CdCl through applying polarization field 2electric dipole after process arranges in the same way.Wherein electric dipole arrangement also can be rightabout.As shown in Figure 5 D, nano dipoles particle solar battery thin film base Rotating fields 150 can at electric field-enhanced CdCl 2the nano dipoles particle solar cell 150 that polarizability is higher is formed " in Technology for Heating Processing 170.Electric field-enhanced CdCl 2treatment process 170 is similar to CdCl 2treatment process 160, but carrying out CdCl 2on the first transparency conductive electrode layer 114, apply polarized electric field while process, intensity is 3000V.Polarized electric field is applied on the first transparency conductive electrode layer 114, thus drives CdS electric dipole 200 in photovoltaic medium 122, form more consistent arrangement in the same way.Complete CdCl 2after heat treatment (as 160 or 170), prepare the second conductive electrode layer on the solar cell, complete battery preparation.
Figure 6 shows that the performance of nano dipoles particle solar cell prepared by embodiment 1, in Fig. 6, compare planar p-n junction battery (conventional batteries) 135 and the described quantum efficiency of nano dipoles particle solar cell (mixed film) 136 and the relation of wavelength.Spectral band is 430 ~ 850nm.Fig. 6 gives glass substrate and tco layer to the impact of solar cell integrated efficiency, and they can absorb the light (glass absorber part 133, TCO absorption portion 134) that a part enters their inside, because this reducing battery efficiency.But nano particle solar cell is compared planar junction battery at the energetic portions (i.e. shortwave strong point, about 430 ~ 550nm wave band) 137 of incident light and is shown very strong improvement.Planar p-n junction battery is because the absorption of CdSn type layer causes in the loss 138 of this wave band.Therefore can convert more light to electricity, thisly to improve in the present output of battery of final body.
Fig. 7 A to 9B gives the measurement data of solar cell prepared by several groups of the present invention, so that CdCl to be described 2treatment process on nano dipoles particle solar cell and not containing the impact of plane solar energy battery (Fig. 7 B, 8B and 9B) performance of nano dipoles, CdCl 2treatment process on the impact of nano dipoles particle solar cell properties as shown in Fig. 7 A, 8A and 9A, CdCl 2treatment process on not containing the impact of plane solar energy battery performance of nano dipoles as shown in Fig. 7 B, 8B and 9B.As shown in Figure 7, the mean value of solar battery efficiency is through CdCl 2promote all to some extent after process.Also find out from figure, at every turn through CdCl 2after process, nano dipoles particle solar cell is compared and is not all shown narrower with more consistent efficiency distribution containing nano dipoles planar junction battery, two kinds of samples show the efficiency (6% and 3.3%) almost differing one times, and the yields of nano dipoles particle solar cell reaches 100%.Therefore, nano particle solar cell large-scale production preferably.
Fig. 8 A and 8B give CdCl 2processing time is on the impact of battery open circuit voltage (Voc).Obviously find out from figure, the open circuit voltage of the nano particle solar cell shown in Fig. 8 A is higher than the open circuit voltage of the planar junction solar cell shown in Fig. 8 B a lot.And two kinds of batteries are at given CdCl 2under processing time, show close short circuit current.
Figure 10 compares the relation between the projectile energy of planar junction and nano particle solar cell and the square value of absorption coefficient and projectile energy product, includes CdCl 2situation before and after process.Absorption coefficient determines the light injection degree of depth in solar cells of specific wavelength.Therefore, high absorption coefficient illustrative material can absorb more luminous energy.To direct band gap material (as CdTe, CdS), when the relation of the long-pending quadratic sum projectile energy pressing absorption coefficient and projectile energy is mapped, curve can provide linear segment.The intercept of linear segment in energy axes is the band gap of this material.Band gap characterizes the required minimum photon energy producing free electron generating, therefore means absorption threshold value.Low band gaps material or structure compare the spectrum that scope can be utilized wider of high band gap.
Figure 10 gives nano solar battery at CdCl 2absorbance curves 250 before treatment.Curve 250 does not provide the clear and definite range of linearity and does not provide very strong ABSORPTION EDGE.Therefore, absorbing threshold value is gradual change, which has limited battery and absorbs the ability that projectile energy produces free electron.Curve group 260 indicates CdCl 2key to nano particle solar cell of process.Sharp-pointed ABSORPTION EDGE is exactly evidence, illustrates that band gap is approximately 1.486eV.By comparing, the curve group 270 not containing the planar junction battery of nano dipoles gives the similar range of linearity and has clear and definite ABSORPTION EDGE, but band gap is higher, is approximately 1.50eV.
Figure 11 describes the current-voltage performance test curve of the CdS nano dipoles particle battery using the inventive method to prepare, and as an instantiation, its preparation method is described above.Although do not have p-n junction structure in battery, the I-V characteristic of diode is obvious.This illustrates that in battery, the granuloplastic polarized electric field of electric dipole serves the one-way conduction effect same with p-n junction electric field.The concrete test performance of this battery is:
Test condition is:
Spectrum AM1.5G
Light intensity 100mW/cm 2
Battery temperature 25 DEG C.
Embodiment 7
Use piezoelectric forces microscope to characterize the sample of solar cell of the present invention, its method is: in piezoelectric forces microscope, install conducting probe, and control system is adjusted to measurement pattern; Under the sample of solar cell of the present invention being put into the microscopical conducting probe of piezoelectric forces, and alternation oscillating voltage is added to probe, then record each coordinate position probe of battery sample surface with the length travel of oscillating voltage and teeter information; Each coordinate position probe of battery sample surface described in collection is with while the length travel of oscillating voltage and teeter information, the probe using lock-in amplifier (Lock-inAmplifier) process to obtain from the microscopical light sensor of piezoelectric forces is with the length travel of oscillating voltage and teeter signal, therefrom filter out the signal with oscillating voltage source same frequency, remove noise.Solar cell surface of the present invention is scanned, and draws out the battery thin film surface length travel of each point or the teeter signal distribution map with corresponding probe coordinate; Phase difference between the local deformation of nano dipoles particle and oscillating voltage can provide the local polarisation directional information of electric dipole particle, and the corresponding probe coordinate of phase difference draws out the vectorial piezoelectric effect distribution map of film.
Figure 12 A, what Figure 12 B described is longitudinal piezoelectric effect (VerticalPFM) by piezoelectric forces microscope (PiezoresponseForceMicroscopy), i.e. Figure 12 A, with piezo-electric traverse effect (LateralPFM), i.e. Figure 12 B, scanning obtains size, the distributed intelligence of nano dipoles particle.Same equipment can also obtain the information of the local polarisation directional spreding of electric dipole by vectorial piezoelectric effect (VectorPFM) scanning.Its principle is, an oscillating voltage 320 is applied by piezoelectric forces microscopic system conducting probe 300 pairs of film surfaces under contact mode, piezoelectric property due to nano dipoles particle 120 can produce the deformation concussion of same frequency under the impact of this local biases, does not have the photovoltaic dielectric material 122 of piezoelectric property then can not change.Therefore solar cell surface of the present invention is scanned, coordinate the position of AFM scan-probe, and draw out the battery thin film surface length travel of each point or the teeter signal distribution map with corresponding probe coordinate, nano dipoles particle and photovoltaic dielectric material can be distinguished, and obtain the information such as distribution, size, shape, electric dipole moment of nano dipoles particle.Draw the distribution map of the local deformation probe coordinate corresponding with the phase difference between oscillating voltage, i.e. vectorial piezoelectric effect distribution map, can provide the information in the electric dipole moment direction of electric dipole particle.
The longitudinal oscillation of probe can be caused when nano dipoles particle stretches, produce longitudinal piezoelectric effect figure, i.e. Figure 12 A; Probe teeter can be caused during tangential deformation, and produce piezo-electric traverse effect figure, be i.e. Figure 12 B.Oscillation Amplitude is then directly proportional to polar intensity.The length travel of probe and teeter can be obtained by four phase light sensors 310 amplifications of PFM system, and record formation scintigram.And the polarised direction of nano dipoles particle and applying bias field direction inconsistent time, the phase place of deformation has and relatively lags behind, and therefore this phase difference can provide the information of electric dipole polarised direction, is called vectorial piezoelectric effect figure.Therefore, this method can also provide the polarised direction of each nano dipoles particle, is the quantitative relationship between the distribution of the macroscopical output characteristic (as open circuit voltage) and its microstructure and electric dipole of setting up this battery, polarised direction.

Claims (7)

1. prepare a method for nano dipoles solar cell, described nano dipoles solar cell comprises substrate layer (112), the first transparency conductive electrode layer (114), photovoltaic effect layer (116) and the second conductive electrode layer (118); The order that the position relationship of described each layer enters with sunlight arranges, be followed successively by the first transparency conductive electrode layer (114), photovoltaic effect layer (116), the second conductive electrode layer (118), it is characterized in that the mixed film first preparing N-shaped material and p-type material, again by the characteristic that is separated of bi-material in high-temperature heat treatment process, isolate N-shaped material and p-type material; When N-shaped material has dipolar nature, be formed in p-type material the numerous molecules inlaying the N-shaped material formation with dipole moment; When p-type material has dipolar nature, in N-shaped material, form the numerous molecules inlaying the p-type material formation with dipole moment;
Described preparation method comprises following steps:
A) cleanly the first described transparency conductive electrode layer (114) or the glass substrate of described the second conductive electrode layer (118) is coated with, then the mixed film of sputtering sedimentation CdTe and CdS in described glass substrate, described film thickness scope is 0.2-20 μm, and the target of use is CdS and CdTe compacting after the mixing of 1:30-1:2.5 scope in mass ratio;
B) glass substrate that deposited CdTe and CdS mixed film is placed in CdCl 2with heat treatment in the mixed-gas atmosphere of air 5-120 minutes, heating-up temperature was 350 ~ 650 DEG C;
C) at CdCl 2film surface after heat treatment re-use sputtering method deposition described in the first transparency conductive electrode layer or the second described conductive electrode layer, the solar cell described in formation.
2. prepare the method for nano dipoles solar cell as claimed in claim 1, it is characterized in that implement described in step a) and step b) while, the first described transparency conductive electrode layer (114) or described the second conductive electrode layer (118) apply polarized electric field, voltage is 10 ~ 3000V, and deposited CdTe and CdS mixed film is placed among electric field.
3. prepare the method for nano dipoles solar cell as claimed in claim 1 or 2, it is characterized in that, in described photovoltaic effect layer (116), described nano dipoles particle is the one in p-type or n-type semiconductor, and photovoltaic absorbing material is the another kind in p-type or N-shaped material; In photovoltaic effect layer (116), each nano dipoles particle produces an electric dipole.
4. prepare the method for nano dipoles solar cell as claimed in claim 1 or 2, it is characterized in that described nano dipoles particle is polarized and arrange in the same way at least partly, nano dipoles polarize particles direction is important on the direction perpendicular to the first transparency conductive electrode layer (114) or the second conductive electrode layer (118).
5. prepare the method for nano dipoles solar cell as claimed in claim 1 or 2, it is characterized in that described nano dipoles particle is by CdS xte (1-x)alloy is formed, x=0 ~ 1; Described photovoltaic absorbing material is made up of CdTe.
6. prepare the method for nano dipoles solar cell as claimed in claim 1, it is characterized in that in prepared nano dipoles solar cell, described photovoltaic effect layer (116) is made up of jointly photovoltaic absorbing material and the nano dipoles particle be embedded in photovoltaic effect layer, and described nano dipoles particle has polarization or piezoelectric properties; The material forming the second conductive electrode layer (118) had both comprised the transparent conductive material identical with the first transparency conductive electrode layer (114), also comprised opaque electric conducting material; When the second conductive electrode layer (118) adopts transparent conductive material to make, form symmetrical structure, this time both entered battery from the first transparency conductive electrode layer (114), also entered battery from the second conductive electrode layer (118); In described symmetrical structure, when substrate layer (112) makes for transparent material, before substrate layer (112) is positioned at the first transparency conductive electrode layer (114) or after being positioned at the second conductive electrode layer (118); When substrate layer (112) is made up of opaque material, after substrate layer (112) is positioned at the second conductive electrode layer (118).
7. the macro property of a quantization signifying nano particle solar cell and the method for relation between its microstructure and polarization characteristic, described nano particle solar cell is obtained by the preparation method described in claim 1 or 6, it is characterized in that, described method passes through longitudinal piezoelectric effect and the piezo-electric traverse effect of the solar cell described in scanning survey, evidence and the distributed intelligence of nano dipoles existence are found in scanning, obtained the information of the local polarisation directional spreding of electric dipole by vectorial piezoelectric effect scanning, step is as follows simultaneously:
A) microscopical for piezoelectric forces probe be replaced by conducting probe and adjust to contact measurement pattern, and alternation oscillating voltage is applied to conducting probe, to described solar cell sample surface scan, and the probe recording each coordinate position is with the length travel of oscillating voltage and teeter information;
B) according to the solar cell sample surface information that step a) obtains, draw out the length travel of described solar battery thin film surface each point or the teeter signal distribution map with corresponding probe coordinate, distinguish nano dipoles particle and photovoltaic absorbing material, and obtain the distribution of nano dipoles particle, size, shape, the size of electric dipole moment and polarizability information;
C) according to step b) obtain between the local deformation of nano dipoles and oscillating voltage phase difference, there is provided the electric dipole moment polarised direction information of electric dipole particle, corresponding probe coordinate draws out the vectorial piezoelectric effect distribution map of described solar battery thin film;
D) size of the electric dipole moment of the nano dipoles particle of solar cell of the present invention, polarizability and direction is measured.
CN201110358135.1A 2011-11-11 2011-11-11 Nano dipoles solar cell and preparation method thereof Active CN103107214B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201110358135.1A CN103107214B (en) 2011-11-11 2011-11-11 Nano dipoles solar cell and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201110358135.1A CN103107214B (en) 2011-11-11 2011-11-11 Nano dipoles solar cell and preparation method thereof

Publications (2)

Publication Number Publication Date
CN103107214A CN103107214A (en) 2013-05-15
CN103107214B true CN103107214B (en) 2016-04-06

Family

ID=48314931

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201110358135.1A Active CN103107214B (en) 2011-11-11 2011-11-11 Nano dipoles solar cell and preparation method thereof

Country Status (1)

Country Link
CN (1) CN103107214B (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104300043A (en) * 2014-09-29 2015-01-21 常州回天新材料有限公司 Solar piezoelectric film compression molding method
CN104393108A (en) * 2014-10-27 2015-03-04 中国科学院半导体研究所 Strong polarization device for high-efficiency nano dipole solar cell and method
CN109427488A (en) * 2017-08-28 2019-03-05 絜静精微有限公司 In conjunction with electrochemistry and the thin-film solar cells epitaxy method of nanometer transfer printing
CN108550634A (en) * 2018-03-15 2018-09-18 上海大学 Using the cadmium-zinc-teiluride radiation detector and preparation method thereof of zinc oxide conductive electrode

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101567274A (en) * 2009-05-21 2009-10-28 长兴化学工业股份有限公司 Dye-sensitized solar battery using compound semiconductor material

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW200425530A (en) * 2002-09-05 2004-11-16 Nanosys Inc Nanostructure and nanocomposite based compositions and photovoltaic devices
JP2008103670A (en) * 2006-09-22 2008-05-01 Nissan Motor Co Ltd Organic thin film photodetector, manufacturing method thereof, organic thin film light receiving/emitting element, manufacturing method thereof, and pulse sensor
US20110048534A1 (en) * 2008-01-24 2011-03-03 University Of Toledo Nanodipole Photovoltaic Devices, Methods of Making and Methods of Use Thereof
DE102008060179A1 (en) * 2008-11-30 2010-07-29 Brandenburgische Technische Universität Cottbus Solar cell with electrostatic local fields in the photoactive area

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101567274A (en) * 2009-05-21 2009-10-28 长兴化学工业股份有限公司 Dye-sensitized solar battery using compound semiconductor material

Also Published As

Publication number Publication date
CN103107214A (en) 2013-05-15

Similar Documents

Publication Publication Date Title
Tang et al. Highly efficient and stable planar heterojunction solar cell based on sputtered and post-selenized Sb2Se3 thin film
Wu High-efficiency polycrystalline CdTe thin-film solar cells
Bouich et al. Experimental, theoretical, and numerical simulation of the performance of CuInxGa (1-x) S2-based solar cells
Islam et al. Thickness study of Al: ZnO film for application as a window layer in Cu (In1− xGax) Se2 thin film solar cell
JP5748787B2 (en) Solar cell and manufacturing method thereof
Liu et al. Preparation of Cu (In, Ga) Se2 thin film by sputtering from Cu (In, Ga) Se2 quaternary target
Rampino et al. 15% efficient Cu (In, Ga) Se2 solar cells obtained by low-temperature pulsed electron deposition
Lugo et al. Characterization of CuInS2 thin films prepared by chemical bath deposition and their implementation in a solar cell
CN103107214B (en) Nano dipoles solar cell and preparation method thereof
Hsu et al. Improvement of Ga distribution and enhancement of grain growth of CuInGaSe2 by incorporating a thin CuGa layer on the single CuInGa precursor
CN106206249B (en) Topological insulator thin film with photovoltaic characteristic and preparation method thereof
Lare et al. ZnO thin films fabricated by chemical bath deposition, used as buffer layer in organic solar cells
Yan et al. Structure and properties of CIGS films based on one-stage RF-sputtering process at low substrate temperature
KR20120080045A (en) Manufacturing method of solar cell
Hu et al. Pulsed laser deposited and sulfurized Cu2ZnSnS4 thin film for efficient solar cell
CN103137770A (en) Graphene/Sip-n double-junction solar cell and preparing method thereof
CN102544230A (en) Method for growing variable forbidden bandwidth cadmium (Cd1)-x zinc (Zn) x tellurium (Te) film
KR101734362B1 (en) Forming method for acigs film at low temperature and manufacturing method for solar cell by using the forming method
KR101782965B1 (en) method for manufacturing solar cell and vacuum deposition equipment used the same
Zhang et al. Fabrication of 4.9% efficient Cu2ZnSnS4 solar cell using electron-beam evaporated CdS buffer layer
Ghorashi et al. Optical simulation and investigation of different coating methods CdS&TiO2 for buffer layer in CIGS solar cell efficiency
Siebentritt Basics of chalcogenide thin film solar cells
CN105144402A (en) Photovoltaic device with graded grain size and S:Se ratio
Ezema et al. EFFECT OF ANNEALING ON THE PROPERTIES OF CHEMICAL BATH DEPOSITED CdS BUFFER LAYER OF CIS SOLAR CELLS.
Pal et al. Chalcogenide-Based 2D Nanomaterials for Solar Cells

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant