CN101882640B - CuInSe2-based thin film solar cell - Google Patents

CuInSe2-based thin film solar cell Download PDF

Info

Publication number
CN101882640B
CN101882640B CN2010102129235A CN201010212923A CN101882640B CN 101882640 B CN101882640 B CN 101882640B CN 2010102129235 A CN2010102129235 A CN 2010102129235A CN 201010212923 A CN201010212923 A CN 201010212923A CN 101882640 B CN101882640 B CN 101882640B
Authority
CN
China
Prior art keywords
film
cuinse
interface
cuin
inse
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.)
Expired - Fee Related
Application number
CN2010102129235A
Other languages
Chinese (zh)
Other versions
CN101882640A (en
Inventor
张晓勇
王东
李学耕
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.)
OPTONY SOLAR (HANGZHOU) CO Ltd
Original Assignee
OPTONY SOLAR (HANGZHOU) CO Ltd
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 OPTONY SOLAR (HANGZHOU) CO Ltd filed Critical OPTONY SOLAR (HANGZHOU) CO Ltd
Priority to CN2010102129235A priority Critical patent/CN101882640B/en
Publication of CN101882640A publication Critical patent/CN101882640A/en
Application granted granted Critical
Publication of CN101882640B publication Critical patent/CN101882640B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • Y02E10/547—Monocrystalline silicon PV cells

Abstract

The invention discloses a CuInSe2-based thin film solar cell, which comprises a substrate, a metal anode, a reflecting layer, a photoelectric conversion layer and a transparent conductive layer in sequence, wherein the reflecting layer comprises CuAlSe2/CuAlxGa(1-x)Se2/CuGaSe2 films in sequence; the photoelectric conversion layer comprises CuIn(1-m)GamSe2/CuInSe(2-y)Sy/Cu(1-a)ZnaInSe(2-b)Sb films; and the transparent conductive layer comprises CdS/i-ZnO/AZO films. In the invention, the photoelectric conversion layer and the reflecting layer are constructed by adopting multilayer film and gradient film technologies; and a better p-n energy band structure can be formed by adjusting and controlling the bottom of a conduction band and a value band edge through interlayer charge migration, so that the long wave response of devices and the collection efficiency of current carriers can be improved and further the photoelectric conversion efficiency of the devices can be improved.

Description

A kind of CuInSe＜sub〉2＜/sub〉based thin film solar cell
Technical field
The invention belongs to technical field of solar batteries, be specifically related to CuInSe 2Based thin film solar cell.
Background technology
At present, commercial solar cell mainly comprises: silica-based wafer battery, thin-film solar cells and GaAs based concentrating solar battery, wherein, CuInSe 2Based thin film solar cell is low because of its production cost, conversion efficiency is high, low light level performance is good, capability of resistance to radiation is strong, no photic decline and can be deposited on the first-class characteristics of flexible substrates, is called " the most promising novel thin film solar cell of next epoch " in the world.
CuInSe 2The structural development of based thin film solar cell has mainly experienced three phases.1976, Kazmerski etc. prepared first CuInSe 2Thin-film solar cells, its structure is: substrate of glass/Mo electrode/low resistance CuInSe 2/ high resistance CuInSe 2/ high resistance CdS/ low resistance CdS/ grid electrode.1981, Boeing etc. studied on the basis forefathers, and preparing that photoelectric conversion efficiency reaches is 9.4% CuInSe 2Thin-film solar cells, its structure is: ceramic bases/Mo/CuInSe 2/ high resistance Cd xZn (1-x)The S/ZnO/ grid electrode, since then, CuInSe 2Thin-film solar cells causes people's extensive attention.After this, people are on the basis of Boeing device, to CuInSe 2The structure of based thin film solar cell has been carried out a large amount of research and optimal design, and obtains structure and be: substrate of glass/Mo/Cu (InGa) Se 2/ CdS/ high resistance ZnO/ low resistance ZnO/MgF 2The thin-film solar cells of/grid electrode, its high conversion efficiency is 19.6%, first of each based thin film solar cell.
In 30 years of development courses, CuInSe 2The structural research of based thin film solar cell and optimal design mainly concentrate on following four aspects:
1. increase CuInSe by congeners displacement doping way 2The optical band gap of material is to improve the open circuit voltage and the conversion efficiency of battery;
2. with other broad stopband film or its combination replacement Cd xZn 1-xS reduces Cd content, increases the transmitance of short wavelength light, increases the short wave response and the short circuit current of battery;
3. use the substrate of alternative pottery of soda-lime glass, stainless steel or polymer or Pyrex as battery;
4. introduce CuInSe 2Base absorbed layer band gap gradual change technology, the open circuit voltage and the carrier collection efficient of raising device;
Wherein, to CuInSe 2The research of absorbent layer structure optimization aspect mainly comprises the following aspects:
1. partly substitute the Cu atom with Ag, Au, or the partly alternative In atom of Al, Ga, or the partly alternative Se atom of S, Te, increase optical band gap with this, improve conversion efficiency.
2. form CuGaSe at the Mo film surface 2Enriched layer increases CuInSe with this 2With the Mo adhesion of thin film, reduce the boundary defect density of states.
3. make Ga content from CuInSe 2/ Mo interface is to CuInSe 2/ CdS interface descends gradually, improves carrier collection efficient by the band gap gradual change.
4. make S content from CuInSe 2/ Mo interface is to CuInSe 2/ CdS interface increases gradually, improves carrier collection efficient by the band gap gradual change.
5. by the varied configurations homojunction photocell of Fermi level, reduce CuInSe with this 2/ CdS interface compound.
Though CuInSe 2The research of based thin film solar cell has obtained great success, but still there is the problem of following two aspects in current device architecture:
Since elements such as Ga, S to CuInSe 2The thin-film material electronic band structure influence difference, the method for single-element content gradually variational can only improve a kind of collection efficiency of charge carrier, and is very limited to the contribution of device conversion efficiency;
2. depletion region is main photoelectric conversion region, but the thickness of depletion region only is 0.1-0.5 μ m (0 bias voltage), much smaller than CuInSe 2The thickness 1.5-2 μ m of rete, so CuInSe 2Layer is high not enough to utilization of incident light.
Summary of the invention
The invention provides a kind of CuInSe 2Based thin film solar cell, its photoelectric conversion layer and reflector are made of the multi-gradient film of Al, Ga, S codope, realize at the bottom of the conduction band of layers of material and the regulation and control of top of valence band by interlayer charge migration, form more excellent p-n junction band structure, with the long wave response of raising device and the collection efficiency of photo-generated carrier, thus the photoelectric conversion efficiency of raising device.
A kind of CuInSe 2Based thin film solar cell is made of substrate, metal positive-pole, reflector, photoelectric conversion layer and transparency conducting layer successively, wherein,
Described reflector is by CuAlSe 2/ CuAl xGa 1-xSe 2/ CuGaSe 2Film constitutes successively, and described photoelectric conversion layer is by CuIn 1-mGa mSe 2/ CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bFilm constitutes successively, and described transparency conducting layer is made of successively the CdS/i-ZnO/AZO film;
That described reflector contacts with described metal positive-pole is CuAlSe 2Film, the interface of described reflector and described photoelectric conversion layer are CuGaSe 2/ CuIn 1-mGa mSe 2Interface, the interface of described photoelectric conversion layer and described transparency conducting layer are Cu 1-aZn aInSe 2-bS b/ CdS interface.
In the described reflector, CuAlSe 2The thickness of film is 5～50nm, is preferably 10nm; CuAl xGa 1-xSe 2The thickness of film is 5～60nm, is preferably 15nm; CuGaSe 2The thickness of film is 10～100nm, is preferably 25nm.CuAlSe 2, CuAl xGa 1-xSe 2And CuGaSe 2Film all adopts the preparation of coevaporation technology.
Wherein, CuAlSe 2Film is a p N-type semiconductor N thin-film material, and its carrier concentration is 1 * 10 18～7 * 10 18/ cm 3, be preferably 5 * 10 18/ cm 3, electron affinity is 2.6eV, and optical band gap is 2.70eV, and top of valence band is 5.35eV to the energy difference of vacuum Fermi level.Described CuAlSe 2The existing higher conductivity of film can form ohmic contact and bigger film-substrate cohesion preferably with metal positive-pole again.Described CuAlSe 2Film can adopt the method for Cu, Al, three kinds of element coevaporations of Se to be prepared from.
Wherein, CuGaSe 2Film is a p N-type semiconductor N thin-film material, and its carrier concentration is 1 * 10 18～7 * 10 18/ cm 3, be preferably 3 * 10 18/ cm 3, electron affinity is 3.69eV, and optical band gap is 1.68eV, and top of valence band is 5.36eV to the energy difference of vacuum Fermi level.Described CuGaSe 2Film can adopt the method for Cu, Ga, three kinds of element coevaporations of Se to be prepared from.
Wherein, CuAl xGa 1-xSe 2Film is CuAlSe 2Film and CuGaSe 2Resilient coating between the film is at CuAlSe 2/ CuAl xGa 1-xSe 2The interface, x=1; At CuAl xGa 1-xSe 2/ CuGaSe 2The interface, x=0; At CuAl xGa 1-xSe 2Film inside, the x value is from CuAlSe 2/ CuAl xGa 1-xSe 2The interface is to CuAl xGa 1-xSe 2/ CuGaSe 2Successively decrease in the interface.
CuAl xGa 1-xSe 2Film is a p N-type semiconductor N thin-film material, and carrier concentration is about 1 * 10 18～7 * 10 18/ cm 3, be preferably 4 * 10 18/ cm 3, optical band gap is from CuAlSe 2The 2.70eV at interface carries out the transition to CuGaSe 2The 1.68eV at interface.Described CuAl xGa 1-xSe 2Film can adopt the method for Cu, Al, Ga, four kinds of element coevaporations of Se to be prepared from.
Adopt CuAl xGa 1-xSe 2Film can reduce CuAlSe as resilient coating 2Film and CuGaSe 2Film directly contacts the lattice mismatch that causes, reduces the boundary defect density of states and charge carrier recombination rate with this, avoids at CuAlSe simultaneously 2/ CuAl xGa 1-xSe 2Interface and CuAl xGa 1-xSe 2/ CuGaSe 2The interface forms can be with spike, improves the collection efficiency of charge carrier with this.
Described CuAlSe 2Film, CuAl xGa 1-xSe 2Film and CuGaSe 2The electron affinity of film satisfies: CuGaSe 2＞CuAl xGa 1-xSe 2＞CuAlSe 2The optical band gap width satisfies: CuAlSe 2＞CuAl xGa 1-xSe 2＞CuGaSe 2Top of valence band satisfies to the energy difference of vacuum Fermi level: CuGaSe 2＞CuAl xGa 1-xSe 2＞CuAlSe 2Carrier concentration satisfies: CuAlSe 2＞CuAl xGa 1-xSe 2＞CuGaSe 2, therefore, when these three kinds of films are pressed CuAlSe 2/ CuAl xGa 1-xSe 2/ CuGaSe 2When the synthetic reflector of der group is in contact with one another, with charge migration between genetic horizon.Charge migration makes each layer have unified Fermi level, and simultaneously the conduction band and the valence band of each layer rise with the rising of Fermi level, descends and descends, consequently: from CuGaSe 2To CuAlSe 2, at the bottom of the conduction band and the position of top of valence band raises gradually, and the absorption coefficient of longwave optical is reduced gradually.Therefore, the effect of following three aspects can be played in the reflector:
(1) by effective field of force the electron reflection to the positive pole diffusion is gone back, improve short circuit current;
(2) reduce absorption, and pass through CuAlSe longwave optical 2/ Mo interface is improved the spectral response of longwave optical to the longwave optical reflected back photoelectricity transition zone that sees through with this;
(3) by optimizing top of valence band, improve the collection efficiency in hole, improve short circuit current with this.
In the described photoelectric conversion layer, described CuIn 1-mGa mSe 2The thickness of film is 100-1500nm, is preferably 800nm; Described CuInSe 2-xS xThe thickness of film is 10～1200nm, is preferably 600nm; Described Cu 1-yZn yInSe 2-xS xThe thickness of film is 10～300nm, is preferably 70nm.
Wherein, CuIn 1-mGa mSe 2Film is the p N-type semiconductor N thin-film material that Ga element and hole concentration are total to gradual change.At CuGaSe 2/ CuIn 1-mGa mSe 2The interface, m=1; At CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, 0.15＜m＜0.24 is preferably m=0.2; At CuIn 1-mGa mSe 2Film inside, the m value is from CuGaSe 2/ CuIn 1-mGa mSe 2The interface is to CuIn 1-mGa mSe 2/ CuInSe 2-yS ySuccessively decrease in the interface.
CuIn 1-mGa mSe 2The optical band gap E of film g, E at the bottom of the conduction band c, top of valence band E vAnd the relation between the representative fraction m of Ga element is respectively:
E g＝1.011+0.42m+0.244m 2 (1)
E c＝4.35-0.42m-0.244m 2 (2)
E v＝E g+E c (3)
Therefore, CuIn 1-mGa mSe 2The optical band gap of film is from CuGaSe 2/ CuIn 1-mGa mSe 2The 1.676eV at interface is reduced to CuIn gradually 1-mGa mSe 2/ CuInSe 2-yS yThe 1.12eV at interface, at the bottom of the conduction band from CuGaSe 2/ CuIn 1-mGa mSe 2The 3.685eV at interface drops to CuIn gradually 1-mGa mSe 2/ CuInSe 2-yS yThe 4.35eV at interface, top of valence band is constant substantially.From CuGaSe 2/ CuIn 1-mGa mSe 2The interface is to CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, hole concentration reduces gradually, and is corresponding, CuIn 1-mGa mSe 2The Fermi level of film is from CuGaSe 2/ CuIn 1-mGa mSe 2The interface is to CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface raises gradually.
Wherein, CuInSe 2-yS yFilm is the P type semiconductor thin-film material that S element and hole concentration are total to gradual change, at CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, y=0; At CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, 0.05＜y＜0.6 is preferably y=0.35; At CuInSe 2-yS yFilm inside, the y value is from CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface is to CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface increases gradually.Opposite with the effect of Ga element, the S element to conduction band at the bottom of influence little, but can significantly reduce top of valence band, thereby increase CuInSe 2The optical band gap of thin-film material.From CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface is to CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, hole concentration reduces gradually, and is corresponding, CuInSe 2-yS yThe Fermi level of film is from CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface is to CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface raises gradually.
Wherein, Cu 1-aZn aInSe 2-bS bFilm is the semiconductor film material that Zn element and S element are total to gradual change.At CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, a=0, b=y, preferred a=0, b=0.35; At Cu 1-aZn aInSe 2-bS bFilm and electrically conducting transparent bed boundary, 0.001＜a＜0.1, b＜2, preferred 0.001＜a＜0.1,0.35＜b＜1, a=0.02 more preferably, b=0.55; At Cu 1-aZn aInSe 2-bS bFilm inside, a and b value are all from CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface is to Cu 1-aZn aInSe 2-bS bFilm and electrically conducting transparent bed boundary increase gradually.
At CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, Cu 1-aZn aInSe 2-bS bBe weak p type, along with the gradient of Zn content (a value) increases progressively, the electron concentration at the bottom of the conduction band increases thereupon, Cu 1-aZn aInSe 2-bS bThe Fermi level of film also increases, Cu 1-aZn aInSe 2-bS bFilm changes the n type of attaching most importance to by weak p type gradually.
Described CuIn 1-mGa mSe 2Film, CuInSe 2-yS yFilm and Cu 1-aZn aInSe 2-bS bThe Fermi level of film satisfies: CuIn 1-mGa mSe 2＜CuInSe 2-yS y＜Cu 1-aZn aInSe 2-bS bTop of valence band satisfies to the energy difference of vacuum Fermi level: CuIn 1-mGa mSe 2＞CuInSe 2-yS y＞Cu 1-aZn aInSe 2-bS bElectron affinity satisfies: CuIn 1-mGa mSe 2＞CuInSe 2-yS yAnd CuIn 1-mGa mSe 2＞Cu 1-aZn aInSe 2-bS b, wherein, CuInSe 2-yS yAnd Cu 1-aZn aInSe 2-bS bElectron affinity very approaching.Therefore, press CuIn when this three-layer thin-film 1-mGa mSe 2/ CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bWhen order composition photoelectric conversion layer contacts with each other, with charge migration between genetic horizon, make each layer have unified Fermi level, the conduction band and the valence band that drive each layer simultaneously move, and form Homojeneous p-n Junction.
In the described transparency conducting layer, the thickness of described CdS film is 30～90nm, is preferably 60nm; The thickness of described i-ZnO film is 10～100nm, is preferably 50nm; The thickness of described AZO film is 300～900nm, is preferably 500nm.The AZO film is that Al is ZnO thin film doped, also can be write as ZnO:Al.
Among the present invention, described substrate can be adopted glass, stainless steel or polymeric material, is preferably the soda-lime glass material, and this is because the thermal coefficient of expansion and the CuInSe of soda-lime glass 2Film is very approaching, adopts soda-lime glass to do substrate and can obtain film-substrate cohesion preferably.In addition, the sodium ion in the soda-lime glass can pass metal positive-pole and enter CuInSe 2Layer, and make oxygen atom occupy CuInSe by catalytic action 2Hole concentration is improved in Se room on the crystal boundary, can also promote CuInSe simultaneously 2Crystal grain obtains the CuInSe of high-quality along the growth of (112) axle 2Thin-film material.
Among the present invention, described metal positive-pole is the Mo film, and its thickness is 0.5～2 μ m, and preferred thickness is 1 μ m, and square resistance is 0.1～0.2 Ω/, can adopt magnetron sputtering method to deposit in substrate and obtain.
Operation principle of the present invention is as follows:
The present invention is by heavy n type transparency conducting layer, heavy n type Cu 1-aZn aInSe 2-bS b, with weak p type CuInSe 2-yS y, weak p type CuIn 1-mGa mSe 2Contact successively forms CuInSe 2The homojunction photocell of base has reduced photo-generated carrier at CdS/CuInSe 2The recombination rate at interface; Simultaneously, form single side abrupt junction with contacting of weak p N-type semiconductor N material,, improve the spectral response of each glistening light of waves incident light with this width that increases depletion region by heavy n type.
The present invention is by the reflector of heavy p type and the CuIn of weak p type 1-mGa mSe 2Contact diffuses to form effective field of force by interlayer charge, strengthens the CuIn outside the depletion region 1-mGa mSe 2Photoelectric conversion result.
The present invention is by making at the bottom of the conduction band and the CuGaSe of Fermi level inverse change 2, CuAl xGa 1-xSe 2And CuAlSe 2Contact makes charge migration between its genetic horizon successively, makes at the bottom of the conduction band and top of valence band raises gradually with this, and optical band gap increases gradually.Raising gradually at the bottom of the conduction band suppressed the diffusion of light induced electron to positive pole, strengthened the motion of light induced electron to negative pole simultaneously; Raising gradually of top of valence band strengthened the motion of hole to positive pole, improved the collecting effect in hole; The increasing gradually of optical band gap reduced the absorption of the relatively poor zone of photoelectric conversion result to longwave optical, makes more longwave optical can arrive CuAlSe 2/ Mo interface, and pass through CuAlSe 2/ Mo interface is reflected back toward photoelectric conversion region, improves the spectral response of longwave optical with this.
The present invention also by the doping of various elements, has increased CuInSe 2The optical band gap of film when increasing open circuit voltage, has reduced short circuit current, has reduced series loss, has therefore improved conversion efficiency.Under the standard radiation parameter, CuInSe of the prior art 2The high conversion efficiency of based thin film solar cell is 19.6%, adopts technical scheme of the present invention, and its high conversion efficiency is reached more than 23%.
With respect to prior art, the present invention has following beneficial technical effects:
(1) by the contacting of heavy n type and weak p type, increase the width of depletion region, the higher depletion region of raising photoelectric conversion efficiency has improved the photoelectric conversion efficiency of device to absorption of incident light with this;
(2) be formed with the effectiveness field action by weak p type with contacting of heavy p type, enable band and bend, strengthen the photoelectric conversion result in p type district outside the depletion region;
(3) effectively suppressed the diffusion of light induced electron by the reflector, and strengthened the diffusion of light induced electron, also optimized collecting effect simultaneously, improved short circuit current the hole to negative pole to positive pole;
(4) by the combination in photoelectric conversion layer and reflector, improve absorption and the conversion effect of device to longwave optical, improve the spectral response of longwave optical with this.
In a word, the present invention passes through the analysis to the action effect of the depletion region of traditional devices and diffusion region, find out the deficiency and the root thereof of traditional devices, on this basis, constructed photoelectric conversion layer and reflector by multilayer film and gradient membrane technology, realized forming more excellent p-n junction band structure at the bottom of the conduction band and the regulation and control of top of valence band by interlayer charge migration, improved the long wave response of device and the collection efficiency of charge carrier, improved the photoelectric conversion efficiency of device with this.
Description of drawings
Fig. 1 is CuInSe of the present invention 2The schematic diagram of based thin film solar cell;
Fig. 2 is CuInSe of the present invention 2The energy band diagram in reflector in the based thin film solar cell, wherein, a is the energy band diagram when not considering charge migration, b is the energy band diagram of each tunic behind the unified Fermi level of formation;
Fig. 3 is CuInSe of the present invention 2The energy band diagram of photoelectric conversion layer in the based thin film solar cell, wherein, a is the energy band diagram of each tunic when not considering charge migration, b is the energy band diagram of each tunic behind the unified Fermi level of formation;
Fig. 4 is CuInSe of the present invention 2The energy band diagram of based thin film solar cell under poised state.
Embodiment
Describe the present invention in detail below in conjunction with embodiment and accompanying drawing, but the present invention is not limited to this.
Embodiment 1
As shown in Figure 1, a kind of CuInSe 2Based thin film solar cell is made of substrate of glass 101, Mo membrane electrode 102, reflector 103, photoelectric conversion layer 104 and transparency conducting layer 105 successively.
Substrate of glass 101 adopts soda-lime glass, and Mo membrane electrode 102 adopts magnetron sputtering method to be deposited on the substrate of glass 101, and the thickness of Mo membrane electrode 102 is 1 μ m, and square resistance is 0.1～0.2 Ω/.
As shown in Figure 2, reflector 103 is by CuAlSe 2/ CuAl xGa 1-xSe 2/ CuGaSe 2Film constitutes successively, wherein, and CuAlSe 2The thickness of film 201 is 10nm; CuAl xGa 1-xSe 2The thickness of film 202 is 15nm; CuGaSe 2The thickness of film 203 is 25nm.
In the reflector 103, CuAlSe 2Film 201 is a p N-type semiconductor N thin-film material, and its carrier concentration is 5 * 10 18/ cm 3, electron affinity is 2.6eV, and optical band gap is 2.70eV, and top of valence band 213 is 5.35eV to the energy difference of vacuum Fermi level, can form ohmic contact preferably with metal positive-pole.
In the reflector 103, CuAl xGa 1-xSe 2Film 202 is CuAlSe 2Film 201 and CuGaSe 2Resilient coating between the film 203 is the p N-type semiconductor N thin-film material of optical band gap and Fermi level 212 gradual changes.At CuAlSe 2/ CuAl xGa 1-xSe 2The interface, x=1; At CuAl xGa 1-xSe 2/ CuGaSe 2The interface, x=0.Along with reducing of x value, CuAl xGa 1-xSe 2The optical band gap of film 202 is from CuAlSe 2The 2.70eV at film 201 interfaces carries out the transition to CuGaSe 2The 1.68eV at film 203 interfaces, carrier concentration is from 5 * 10 18/ cm 3Be reduced to 3 * 10 gradually 18/ cm 3
In the reflector 103, CuGaSe 2Film 203 is a p N-type semiconductor N thin-film material, and its electron affinity is 3.69eV, and optical band gap is 1.68eV, and top of valence band 213 is 5.36eV to the energy difference of vacuum Fermi level, and carrier concentration is 2 * 10 18/ cm 3
In the reflector 103, adopt CuAl xGa 1-xSe 2Film 202 reduces CuAlSe as resilient coating 2Film 201 and CuGaSe 2Film 203 directly contacts the lattice mismatch that causes, reduces interface state density and charge carrier recombination rate with this, avoids at CuAlSe simultaneously 2 Film 201 and CuGaSe 2Film 202 interfaces form can be with spike, improves the collection efficiency of charge carrier with this.
Described CuAlSe 2Film 201, CuAl xGa 1-xSe 2Film 202 and CuGaSe 2The electron affinity of film 203 satisfies: CuGaSe 2＞CuAl xGa 1-xSe 2＞CuAlSe 2The optical band gap width satisfies: CuAlSe 2＞CuAl xGa 1-xSe 2＞CuGaSe 2The height of Fermi level 212 satisfies: CuGaSe 2＞CuAl xGa 1-xSe 2＞CuAlSe 2The height basically identical of top of valence band 213, therefore, in the time of this three-layer thin-film contact, with charge migration between genetic horizon.Charge migration makes CuAlSe 2Film 201, CuAl xGa 1-xSe 2Film 202 and CuGaSe 2Film 203 has unified Fermi level 222, at the bottom of the conduction band of simultaneously above-mentioned three-layer thin-film 211 and top of valence band 213 rise with the rising of Fermi level, descend and descend, consequently: from CuGaSe 2Film 203 to CuAlSe 2Film 201, at the bottom of the conduction band 221 and the position of top of valence band 223 raise gradually, the absorption coefficient of longwave optical is reduced gradually being with shown in Fig. 2 b of formation.Therefore, the reflector can by the effective field of force to the electron reflection of positive pole diffusion to negative pole, improve the collection efficiency in hole simultaneously, improve short circuit current with this; Can also see through longwave optical and pass through CuAlSe 2/ Mo interface is improved the quantum efficiency of longwave optical to the longwave optical reflected back photoelectricity transition zone that sees through with this.
As shown in Figure 3, photoelectric conversion layer 104 is by CuIn 1-mGa mSe 2/ CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bFilm constitutes successively, wherein, and CuIn xGa 1-xSe 2The thickness of film 301 is 700nm; CuInSe 2-xS xThe thickness of film 302 is 500nm; Cu 1-yZn yInSe 2-xS xThe thickness of film 303 is 70nm.
In the photoelectric conversion layer 104, CuIn 1-mGa mSe 2Film 301 is p N-type semiconductor N thin-film materials that Ga element and hole concentration are total to gradual change.At CuGaSe 2/ CuIn 1-mGa mSe 2The interface, m=1; At CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, m=0.2 is from CuGaSe 2/ CuIn 1-mGa mSe 2The interface is to CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, the m value reduces gradually, and is corresponding, CuIn 1-mGa mSe 2The optical band gap of film 301 is reduced to 1.011eV, CuIn gradually from 1.676eV 1-mGa mSe 2311 are bent downwardly gradually at the bottom of the conduction band of film 301, and its electron affinity is increased to 4.35eV, CuIn gradually from 3.685eV 1-mGa mSe 2The top of valence band 313 of film 301 is constant substantially, and hole concentration is from CuGaSe 2/ CuIn 1-mGa mSe 2The interface is to CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface reduces gradually, CuIn 1-mGa mSe 2312 of the Fermi levels of film 301 raise gradually.
In the photoelectric conversion layer 104, CuInSe 2-yS yFilm 302 is P type semiconductor thin-film materials that S element and hole concentration are total to gradual change, at CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, y=0 is at CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, y=0.35.From CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface is to CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, the y value increases gradually, correspondingly, CuInSe 2-yS y311 do not have marked change at the bottom of the conduction band of film 302, CuInSe 2-yS yThe top of valence band 313 of film 302 descends gradually, CuInSe 2-yS y The Fermi level 312 of film 302 raises gradually.
In the photoelectric conversion layer 104, Cu 1-aZn aInSe 2-bS bFilm 303 is semiconductor film materials that Zn element and S element are total to gradual change.At CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, a=0, b=0.35; At Cu 1-aZn aInSe 2-bS bThe interface of the CdS film of film and transparency conducting layer, a=0.02.B==0.55; From CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface is to Cu 1-aZn aInSe 2-bS bThe interface of the CdS film of film and transparency conducting layer, a and b value increase gradually, correspondingly, Cu 1-aZn aInSe 2-bS b311 do not have marked change at the bottom of the conduction band of film 303, Cu 1-aZn aInSe 2-bS bThe top of valence band 313 of film 303 reduces gradually, Cu 1-aZn aInSe 2-bS b The Fermi level 312 of film 303 raises gradually.At CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, Cu 1-aZn aInSe 2-bS bFilm is weak p type, along with the gradient of Zn content (a value) increases progressively Cu 1-aZn aInSe 2-bS bFilm changes the n type of attaching most importance to by weak p type gradually.
Described CuIn 1-mGa mSe 2Film 301, CuInSe 2-yS yFilm 302 and Cu 1-aZn aInSe 2-bS bThe Fermi level of film 303 satisfies: CuIn 1-mGa mSe 2＜CuInSe 2-yS y＜Cu 1-aZn aInSe 2-bS bTop of valence band satisfies to the energy difference of vacuum Fermi level: CuIn 1-mGa mSe 2＞CuInSe 2-yS y＞Cu 1-aZn aInSe 2-bS bElectron affinity satisfies: CuIn 1-mGa mSe 2＞CuInSe 2-yS yAnd CuIn 1-mGa mSe 2＞Cu 1-aZn aInSe 2-bS b, wherein, CuInSe 2-yS yAnd Cu 1-aZn aInSe 2-bS bElectron affinity very approaching.Therefore, in the time of this three-layer thin-film contact, with charge migration between genetic horizon, make each layer have unified Fermi level, the conduction band and the valence band that drive each layer simultaneously move, and form CuInSe 2The base Homojeneous p-n Junction is shown in Fig. 3 b.Wherein, 321,322 and 323 be conduction band after the balance respectively at the bottom of, Fermi level and top of valence band.
Transparency conducting layer 105 is made of successively the CdS/i-ZnO/AZO film, and wherein, the thickness of CdS film is 60nm; The thickness of i-ZnO is 50nm; The thickness of AZO is 500nm.
Fig. 4 is above-mentioned CuInSe 2The schematic diagram of the band structure of based thin film solar cell under poised state, wherein, 101 is substrate of glass, 102 is the Mo membrane electrode, 103 is the reflector, and 104 is photoelectric conversion layer, and 105 is transparency conducting layer, 401 be conduction band at the bottom of, 402 is Fermi level, 403 is top of valence band.As can be seen from Figure 4:
1. from CdS/Cu 1-aZn aInSe 2-bS bThe interface is to CuAlSe 2/ Mo interface, at the bottom of the conduction band 401 and top of valence band 403 all form a curve that tilt to rise, this band structure helps the electronics drift to anodal (Mo membrane electrode) to the drift of negative pole (transparency conducting layer) and the hole in the valence band in the conduction band, can effectively improve the short circuit current of device.
2. from CdS/Cu 1-aZn aInSe 2-bS bThe interface is to CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, optical band gap reduces gradually, and the absorption of incident light coefficient is increased gradually.Because this district is the zone of photoelectric conversion result the best, therefore, the absorption coefficient increase can make more light be absorbed in this zone, and is converted to more electric energy.
From CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface is to CuAlSe 2/ Mo interface, optical band gap increases gradually, and the absorption of incident light coefficient is reduced gradually.Because this zone photoelectric conversion result is lower, thereby absorption coefficient reduces to reduce this zone to absorption of incident light, makes incident light see through this zone as much as possible and arrives CuAlSe 2/ Mo interface, and pass through CuAlSe 2The reflection at/Mo interface enters photoelectric conversion layer once more, thus by fully, absorb efficiently and change.
3.p-n the interface of knot is at Cu 1-aZn aInSe 2-bS bIn the film 303, but not CdS/Cu 1-aZn aInSe 2-bS bThe interface, this design has significantly reduced CdS/Cu 1-aZn aInSe 2-bS bThe defect state at interface and complex centre are to the compound influence of electron-hole pair.
Above-mentioned CuInSe 2The operation principle of based thin film solar cell structure is as follows:
Heavy n type transparency conducting layer, heavy n type Cu 1-aZn aInSe 2-bS bFilm 303, with weak p type CuInSe 2-yS yFilm 302, weak p type CuIn 1-mGa mSe 2Film 301 contacts successively, forms CuInSe 2The homojunction photocell of base has reduced photo-generated carrier at CdS/CuInSe 2The recombination rate at interface; Simultaneously, form single side abrupt junction with contacting of weak p N-type semiconductor N material, increase the width of depletion region, improved the spectral response of each glistening light of waves incident light by heavy n type.
The reflector of heavy p type and the CuIn of weak p type 1-mGa mSe 2Film 301 contacts diffuse to form effective field of force by interlayer charge, strengthen the CuIn outside the depletion region 1-mGa mSe 2The photoelectric conversion result of film 301.
At the bottom of the conduction band and the CuGaSe of Fermi level inverse change 2Film 203, CuAl xGa 1-xSe 2Film 202 and CuAlSe 2Film 201 contacts successively, makes at the bottom of the conduction band and top of valence band raises gradually by interlayer charge migration, and optical band gap increases gradually.Raising gradually at the bottom of the conduction band suppressed the diffusion of light induced electron to positive pole, strengthened the motion of light induced electron to negative pole simultaneously; Raising gradually of top of valence band strengthened the motion of photohole to positive pole, improved the collecting effect in hole; The increasing gradually of optical band gap reduced the absorption of the relatively poor zone of photoelectric conversion result to longwave optical, makes more longwave optical can arrive CuAlSe 2/ Mo interface, and pass through CuAlSe 2/ Mo interface is reflected back toward photoelectric conversion region, improves the spectral response of longwave optical with this.
In addition, the doping of Ga, Al, the various elements of S has increased CuInSe 2The optical band gap of base film when increasing open circuit voltage, has reduced short circuit current, has reduced series loss, has therefore improved conversion efficiency.
The CuInSe of present embodiment 2The photoelectric conversion efficiency of based thin film solar cell under the standard radiation parameter can reach more than 23%.
Embodiment 2
With embodiment 1, except:
CuAlSe 2The thickness of film 201 is 15nm, CuAl xGa 1-xSe 2The thickness of film 202 is 20nm, CuGaSe 2The thickness of film 203 is 30nm; CuIn xGa 1-xSe 2The thickness of film 301 is 750nm; CuInSe 2-xS xThe thickness of film 302 is 550nm; Cu 1-yZn yInSe 2-xS xThe thickness of film 303 is 100nm; The thickness of CdS film is 50nm, and the thickness of i-ZnO film is 60nm, and the thickness of AZO film is 800nm.
The CuInSe of present embodiment 2The photoelectric conversion efficiency of based thin film solar cell under the standard radiation parameter can reach more than 23%.
Embodiment 3
With embodiment 1, except:
CuAlSe 2The thickness of film 201 is 20nm, CuAl xGa 1-xSe 2The thickness of film 202 is 50nm, CuGaSe 2The thickness of film 203 is 20nm; CuIn xGa 1-xSe 2The thickness of film 301 is 850nm; CuInSe 2-xS xThe thickness of film 302 is 450nm; Cu 1-yZn yInSe 2-xS xThe thickness of film 303 is 120nm; The thickness of CdS film is 70nm, and the thickness of i-ZnO film is 70nm, and the thickness of AZO film is 650nm.
The CuInSe of present embodiment 2The photoelectric conversion efficiency of based thin film solar cell under the standard radiation parameter can reach more than 22%.
Embodiment 4
With embodiment 1, except:
At CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, m=0.15; CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, y=0.55; At Cu 1-aZn aInSe 2-bS bThe interface of film and transparency conducting layer, a=0.025, b=0.75.
The CuInSe of present embodiment 2The photoelectric conversion efficiency of based thin film solar cell under the standard radiation parameter can reach more than 21%.
Embodiment 5
With embodiment 1, except:
At CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, m=0.24; At CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, y=0.60; At Cu 1-aZn aInSe 2-bS bFilm and electrically conducting transparent bed boundary, a=0.015, b=0.9.
The CuInSe of present embodiment 2The photoelectric conversion efficiency of based thin film solar cell under the standard radiation parameter can reach more than 21%.

Claims (6)

1. CuInSe 2Based thin film solar cell is made of substrate, metal positive-pole, reflector, photoelectric conversion layer and transparency conducting layer successively, it is characterized in that,
Described reflector is by CuAlSe 2/ CuAl xGa 1-xSe 2/ CuGaSe 2Film constitutes successively, and described photoelectric conversion layer is by CuIn 1-mGa mSe 2/ CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bFilm constitutes successively, and described transparency conducting layer is made of successively the CdS/i-ZnO/AZO film; Described AZO film is that Al is ZnO thin film doped;
That described reflector contacts with described metal positive-pole is CuAlSe 2Film, the interface of described reflector and described photoelectric conversion layer are CuGaSe 2/ CuIn 1-mGa mSe 2Interface, the interface of described photoelectric conversion layer and described transparency conducting layer are Cu 1-aZn aInSe 2-bS b/ CdS interface;
In the described reflector, CuAl xGa 1-xSe 2Film is CuAlSe 2Film and CuGaSe 2Resilient coating between the film is at CuAlSe 2/ CuAl xGa 1-xSe 2The interface, x=1; At CuAl xGa 1-xSe 2/ CuGaSe 2The interface, x=0; At CuAl xGa 1-xSe 2Film inside, the x value is from CuAlSe 2/ CuAl xGa 1-xSe 2The interface is to CuAl xGa 1-xSe 2/ CuGaSe 2Successively decreased to x=0 by x=1 in the interface;
In the described photoelectric conversion layer, at CuGaSe 2/ CuIn 1-mGa mSe 2The interface, m=1; At CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, 0.15＜m＜0.24; At CuIn 1-mGa mSe 2Film inside, the m value is from CuGaSe 2/ CuIn 1-mGa mSe 2The interface is to CuIn 1-mGa mSe 2/ CuInSe 2-yS ySuccessively decreased by m=1 to 0.15＜m＜0.24 in the interface;
In the described photoelectric conversion layer, at CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface, y=0; At CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, 0.05＜y＜0.6; At CuInSe 2-yS yFilm inside, the y value is from CuIn 1-mGa mSe 2/ CuInSe 2-yS yThe interface is to CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface is increased gradually by y=0 to 0.05＜y＜0.6;
In the described photoelectric conversion layer, at CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface, a=0, b=y; At Cu 1-aZn aInSe 2-bS b/ CdS interface, 0.001＜a＜0.1, b＜2; At Cu 1-aZn aInSe 2-bS bFilm inside, a value is from CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface is to Cu 1-aZn aInSe 2-bS b/ CdS interface is increased gradually by a=0 to 0.001＜a＜0.1, and the b value is from CuInSe 2-yS y/ Cu 1-aZn aInSe 2-bS bThe interface is to Cu 1-aZn aInSe 2-bS b/ CdS interface is increased to b＜2 gradually by b=y.
2. CuInSe as claimed in claim 1 2Based thin film solar cell is characterized in that, in the described reflector, and CuAlSe 2The thickness of film is 5～50nm, CuAl xGa 1-xSe 2The thickness of film is 5-60nm, CuGaSe 2The thickness of film is 10～100nm.
3. CuInSe as claimed in claim 1 2Based thin film solar cell is characterized in that, in the described photoelectric conversion layer, and CuIn 1-mGa mSe 2The thickness of film is 100～1500nm, CuInSe 2-xS xThe thickness of film is 10～1200nm, Cu 1-yZn yInSe 2-xS xThe thickness of film is 10～300nm.
4. CuInSe as claimed in claim 1 2Based thin film solar cell is characterized in that, in the described transparency conducting layer, the thickness of CdS is 30～90nm, and the thickness of i-ZnO is 10～100nm, and the thickness of AZO is 300～900nm.
5. CuInSe as claimed in claim 1 2The based thin film solar cell structure is characterized in that, described substrate is a soda-lime glass.
6. CuInSe as claimed in claim 1 2The based thin film solar cell structure is characterized in that, described metal positive-pole is the Mo film, and its thickness is 0.5～2 μ m.
CN2010102129235A 2010-06-28 2010-06-28 CuInSe2-based thin film solar cell Expired - Fee Related CN101882640B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2010102129235A CN101882640B (en) 2010-06-28 2010-06-28 CuInSe2-based thin film solar cell

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2010102129235A CN101882640B (en) 2010-06-28 2010-06-28 CuInSe2-based thin film solar cell

Publications (2)

Publication Number Publication Date
CN101882640A CN101882640A (en) 2010-11-10
CN101882640B true CN101882640B (en) 2011-08-10

Family

ID=43054594

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2010102129235A Expired - Fee Related CN101882640B (en) 2010-06-28 2010-06-28 CuInSe2-based thin film solar cell

Country Status (1)

Country Link
CN (1) CN101882640B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103508406B (en) * 2012-06-29 2016-08-24 无锡华润上华半导体有限公司 AZO thin film, preparation method and include its MEMS
CN113899458A (en) * 2021-09-22 2022-01-07 Oppo广东移动通信有限公司 Optical sensor and electronic device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100383982C (en) * 2004-06-14 2008-04-23 王东生 Multi-absorbing-layer solar battery and manufacturing method thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060060237A1 (en) * 2004-09-18 2006-03-23 Nanosolar, Inc. Formation of solar cells on foil substrates
JP2008218937A (en) * 2007-03-08 2008-09-18 Showa Shell Sekiyu Kk Small-sized (small-area) cis-based thin film solar cell module

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100383982C (en) * 2004-06-14 2008-04-23 王东生 Multi-absorbing-layer solar battery and manufacturing method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
JP特开2008-218937A 2008.09.18

Also Published As

Publication number Publication date
CN101882640A (en) 2010-11-10

Similar Documents

Publication Publication Date Title
KR101372536B1 (en) Tandem Thin Film Solar Cell And Fabrication Method Thereof
CN102054897B (en) Method for preparing thin film solar cell from multi-element alloy single target material
CN207320169U (en) A kind of perovskite battery of graded bandgap
US9812593B2 (en) Solar cell and preparing method of the same
CN102396076B (en) Solar battery and production method for same
EP2430670A1 (en) Tandem photovoltaic cell and method using three glass substrate configuration
US8044477B1 (en) Photovoltaic device and method for making
CN101097968A (en) Highly-effective laminate solar battery and method for making same
CN103426943B (en) A kind of copper-zinc-tin-sulfur film solar cell rhythmo structure and its preparation method
JP4394366B2 (en) Double-sided solar cell
KR102350885B1 (en) Solar cell
CN101127371A (en) A nano structure thin film solar battery and its making method
US9941424B2 (en) Solar cell
US8227291B2 (en) Method of manufacturing stacked-layered thin film solar cell with a light-absorbing layer having band gradient
US9691927B2 (en) Solar cell apparatus and method of fabricating the same
CN102244111A (en) Thin film solar cell
CN103988317B (en) Solar cell and solar module
CN101882640B (en) CuInSe2-based thin film solar cell
CN107039554A (en) A kind of cadmium telluride diaphragm solar battery and preparation method
CN104600146A (en) Double-sided thin-film solar cell
CN206460967U (en) A kind of cadmium telluride diaphragm solar battery
CN201708162U (en) CuInSe2-based thin film solar cell
CN108172645A (en) A kind of CIGS/CdTe lamination solar cells and preparation method thereof
CN208570618U (en) A kind of solar battery
KR20090034079A (en) Solar cell using mose2 layer and fabrication method thereof

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
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20110810

Termination date: 20210628

CF01 Termination of patent right due to non-payment of annual fee