CN205542804U - Full back electrode solar cell - Google Patents

Abstract

The utility model discloses a full back electrode solar cell, front surface n+ diffuse layer, preceding surface passivation layer and front surface including superposeing in proper order at n type silicon front surface increase the layer of turning over, the stack of crisscross interval is regional with the surperficial p+ diffuse layer of the back of the body at the surperficial n+ diffuse layer of the back of the body on n type silicon back of the body surface, the surperficial n+ diffuse layer of back of the body region and the surperficial p+ diffuse layer region of the back of the body coat is stamped out -of -the -way surface passivation layer, be connected with the battery negative pole on the surperficial n+ diffuse layer region of the back of the body, be connected with the battery positive pole on the surperficial p+ diffuse layer region of the back of the body, battery positive pole and battery negative pole are formed by electrocondution slurry sintering of the same race. Adopt positive electrode that electrocondution slurry sintering of the same race formed and negative electrode and the surperficial p+ diffuse layer of the n type silicon back of the body and n+ diffuse layer to form the electrical contact, the contact resistance of formation is rateed lessly, has just simplified the production technology of IBC battery greatly, has reduced the manufacturing cost of IBC battery.

Description

A kind of all back-contact electrodes solaode

Technical field

This utility model belongs to area of solar cell, is specifically related to a kind of all back-contact electrodes solaode Production technology.

Background technology

Instantly, the core of the industrial revolution for the third time is new forms of energy revolutions, improves solar battery efficiency technology As the key of raising solar energy utilization ratio, represent the technological development direction of advanced person, China's photovoltaic is produced Structural adjustment and the sustainable development of industry have material impact, belong to the important technical that currently should develop it One.

Current crystal silicon solar energy battery is fabricated by by N-shaped or p-type silicon.With regard to the p-type crystalline silicon sun From the point of view of energy battery, owing to burning the application of front side silver paste and back field aluminum paste, cause silicon chip battery technique simple, Cost is relatively low, so p-type crystal silicon solar energy battery is current main product, and the p-type of current main flow Silicon solar cell efficiency can be stablized more than 19%, but wants do not changing battery structure and gold Efficiency is improved further the most extremely difficult in the case of belonging to metallization processes.

The usual carrier lifetime of n-type silicon chip is longer, and battery efficiency can do more, simultaneously photo attenuation Little, the gross generation of battery is the highest, is the Main way of high efficiency crystalline silicon solar cell from now on, wherein Three kinds of N-shaped type silicon solar cells may become the solaode of main flow within the coming years below, They are, (1) fourchette type back contacts (IBC) solaode: SunPower company, can produce The IBC solaode of the highest transformation efficiency of 25%.The flexible solar battery of Solexel, falls within IBC battery, the electrocondution slurry currently with the exploitation of Sichuan milky way Xing Yuan Science and Technology Ltd. makes electrical contact with, Efficiency is up to 21.5%.(2) n-type silicon type double-sided solar battery: English profit solar energy, panda battery, Efficiency > 20%.(3) n-type silicon heterojunction solar battery: PANASONIC, 25.6%, optimal effect Rate.The potentiality of solaode the most traditional the most substituted silicon solar cell of three of the above type. Wherein, the feature of all back-contact electrodes (fourchette type back contacts) IBC crystal silicon solar batteries is that front is without palisade Electrode, both positive and negative polarity cross arrangement is rearward.The battery structure that this front metal grid removes has a lot Advantage: (1) reduces front shading loss, is equivalent to add effective quasiconductor area；(2) assembly Assembly cost reduces；(3) IBC battery component is of superior reliability；(4) if the live width of silver is sufficiently small, IBC battery can use with double-side cell, can further improve integral battery door efficiency.But this solar energy The preparation process of battery needs to print different electrocondution slurries, and respectively can only be at p+ diffusion layer or n+ Form electrical contact both positive and negative polarity on diffusion layer, and the contact resistivity of the positive and negative electrode formed is higher.

Utility model content

A purpose of the present utility model is to solve at least the above and/or defect, and provides after at least Advantage by explanation.

In order to realize according to these purposes of the present utility model and further advantage, it is provided that a kind of all back-contact electrodes Solaode, is passivated including front surface n+ diffusion layer, the front surface being sequentially overlapped at n-type silicon front surface Layer and front surface increase anti-layer；Staggered interval be superimposed upon n-type silicon back surface back surface n+ diffusion layer region and Back surface p+ diffusion layer region, on described back surface n+ diffusion layer region and back surface p+ diffusion layer region It is coated with back surface passivation layer；Connect on described back surface n+ diffusion layer region and have battery cathode；The described back of the body Connect on surface p+diffusion layer region and have anode；Described anode and battery cathode are by same conductive Slurry sintering forms.

Preferably, described n-type silicon is N-shaped monocrystal silicon, and its resistivity at 1-12 Ω cm, thickness is 100-150 micron；Described n-type silicon front surface is provided with matte.

Preferably, the junction depth of described front surface n+ diffusion layer is 0.1～0.5 μm.

Preferably, described front surface passivation layer is matte passivation layer；Described front surface passivation layer is for first to use Thermal oxidation method one layer of SiO of deposition₂Film, then using plasma strengthens chemical vapour deposition technique at SiO₂ Layer of sin is deposited on film_xFilm；

Preferably, described SiO₂The thickness of film is 2～10 nanometers；Described SiN_xThe thickness of film is 40～100 Nanometer.

Preferably, described front surface increases anti-layer is that matte increases anti-layer；It is SiN that described front surface increases anti-layer_x Film layer；Described SiN_xThe thickness of film layer is 40～100 nanometers.

Preferably, the junction depth of described back surface n+ diffusion layer and back surface p+ diffusion layer is 0.1～0.5 μ m；The square resistance of described back surface n+ diffusion layer is 15～80 Ω/.

Preferably, the thickness that described back surface passivation layer is is 50～80nm.

Preferably, described back surface passivation layer is SiN_xFilm layer, SiO₂/Si₃N₄Stack membrane, SiO₂/Al₂O₃/Si₃N₄Stack membrane, Al₂O₃/Si₃N₄Any one in stack membrane.

Preferably, the width of described anode is 45～80um, and the width of described battery cathode is 45～80um.

This utility model at least includes following beneficial effect: the positive and negative electrode of all back-contact electrodes solaode The back surface of the n-type silicon being all made in, decreases shading-area, adds photogenerated current, can be preferably Collect the electric current that n-type silicon chip produces, use anelectrode and the negative electricity of same conductive slurry sintering simultaneously Pole forms electrical contact with n-type silicon back surface p+ diffusion layer and n+ diffusion layer, and the contact resistivity of formation is less, And enormously simplify the production technology of IBC battery, reduce the production cost of IBC battery.

Part is embodied by further advantage of the present utility model, target and feature by description below, part Also will be by research of the present utility model and practice be understood by the person skilled in the art.

Accompanying drawing illustrates:

Fig. 1 is the structural representation of all back-contact electrodes solaode described in one embodiment of this utility model；

Detailed description of the invention:

Below in conjunction with the accompanying drawings this utility model is described in further detail, to make those skilled in the art Can implement according to this with reference to description word.

Should be appreciated that used herein such as " have ", " comprising " and " including " term also Do not allot other element one or more or the existence of a combination thereof or interpolation.

Fig. 1 shows all back-contact electrodes solaode of the present utility model, including being sequentially overlapped at n-type silicon The front surface n+ diffusion layer 2 of 1 front surface, front surface passivation layer 3 and front surface increase anti-layer 4；Staggered interval It is superimposed upon back surface n+ diffusion layer region 5 and the back surface p+ diffusion layer region 6 of n-type silicon 1 back surface, It is coated with back surface passivation layer on described back surface n+ diffusion layer region 5 and back surface p+ diffusion layer region 6 7；Connect on described back surface n+ diffusion layer region 5 and have battery cathode 8；Described back surface p+ diffusion layer Connect on region 6 and have anode 9；Described anode 9 and battery cathode 8 are by same conductive slurry Sintering forms.

In technique scheme, use the positive and negative electrode of battery to be all made in the back side of n-type silicon, subtract Lack shading-area, added photogenerated current, can preferably collect the electric current that silicon chip produces, use simultaneously The anelectrode of same conductive slurry sintering and negative electrode and n-type silicon back surface p+ diffusion layer region 6 and N+ diffusion layer region 5 forms electrical contact, and the contact resistivity formed is less, enormously simplify IBC electricity The production technology in pond, reduces the production cost of IBC battery.

In another kind of embodiment, described n-type silicon is N-shaped monocrystal silicon, its resistivity at 1-12 Ω cm, Thickness is 100-150 micron；Described n-type silicon front surface is provided with matte.

In another kind of embodiment, the junction depth of described front surface n+ diffusion layer is 0.1～0.5 μm.

In another kind of embodiment, described front surface passivation layer is matte passivation layer；Described front surface is passivated Layer is first to deposit one layer of SiO with thermal oxidation method₂Film, then using plasma strengthens chemical gaseous phase deposition skill Art is at SiO₂Layer of sin is deposited on film_xFilm, uses the front surface of passivation layer passivation cell to effectively reduce The recombination rate of surface minority carrier, improves the surface photon life-span.

In another kind of embodiment, described SiO₂The thickness of film is 2～10 nanometers；Described SiN_xThe film of film Thickness is 40～100 nanometers, SiO₂Film has good passivation, reduces minority carrier answering on surface Close, increase the short circuit current of battery；SiN_xFilm is as anti-reflection film, and thickness is 40～during 100 nanometer to light There is optimal antireflective effect, thus increase battery conversion efficiency.

In another kind of embodiment, it is that matte increases anti-layer that described front surface increases anti-layer；Described front surface increases anti- Layer is SiN_xFilm layer；Described SiN_xThe thickness of film layer is 40～100 nanometers；Described front surface increases anti-layer energy Enough increase light transmission rate.

In another kind of embodiment, the junction depth of described back surface n+ diffusion layer and back surface p+ diffusion layer is 0.1～0.5 μm；The square resistance of described back surface n+ diffusion layer is 15～80 Ω/.

In another kind of embodiment, the thickness that described back surface passivation layer is is 50～80nm；Use passivation The back surface of layer passivation cell can effectively reduce the recombination rate of surface minority carrier, improves surface light The sub-life-span.

In another kind of embodiment, described back surface passivation layer is SiN_xFilm layer, SiO₂/Si₃N₄Stack membrane, SiO₂/Al₂O₃/Si₃N₄Stack membrane, Al₂O₃/Si₃N₄Any one in stack membrane.

In another kind of embodiment, the width of described anode is 45～80um, described battery cathode Width is 45～80um.

Number of devices described herein and treatment scale are used to simplify explanation of the present utility model.To this Those skilled in the art is come by the application of all back-contact electrodes solaode of utility model, modifications and variations Say and be apparent from.

Although embodiment of the present utility model is disclosed as above, but it is not restricted to description and reality Executing listed in mode utilization, it can be applied to various applicable field of the present utility model completely, for For those skilled in the art, it is easily achieved other amendment, therefore without departing substantially from claim And under the general concept that limited of equivalency range, this utility model is not limited to specific details and shows here The legend gone out and describe.

Claims (10)

1. an all back-contact electrodes solaode, it is characterised in that include being sequentially overlapped table before n-type silicon The front surface n+ diffusion layer in face, front surface passivation layer and front surface increase anti-layer；Staggered interval is superimposed upon N-shaped The back surface n+ diffusion layer region of silicon back surface and back surface p+ diffusion layer region, described back surface n+ expands Dissipate and be coated with back surface passivation layer on layer region and back surface p+ diffusion layer region；Described back surface n+ spreads Connect on layer region and have battery cathode；Connect on described back surface p+ diffusion layer region and have anode；Institute State anode and battery cathode to be formed by same conductive slurry sintering.

2. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described n-type silicon For N-shaped monocrystal silicon, its resistivity is at 1-12 Ω cm, and thickness is 100-150 micron；Described n-type silicon Front surface is provided with matte.

3. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described front surface The junction depth of n+ diffusion layer is 0.1～0.5 μm.

4. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described front surface Passivation layer is matte passivation layer；Described front surface passivation layer is first to deposit one layer of SiO with thermal oxidation method₂Film, Then using plasma strengthens chemical vapour deposition technique at SiO₂Layer of sin x film is deposited on film；

5. all back-contact electrodes solaode as claimed in claim 4, it is characterised in that described SiO₂ The thickness of film is 2～10 nanometers；Described SiN_xThe thickness of film is 40～100 nanometers.

6. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described front surface Increasing anti-layer is that matte increases anti-layer；It is SiN that described front surface increases anti-layer_xFilm layer；Described SiN_xThe thickness of film layer It is 40～100 nanometers.

7. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described back surface The junction depth of n+ diffusion layer and back surface p+ diffusion layer is 0.1～0.5 μm；Described back surface n+ diffusion layer Square resistance is 15～80 Ω/.

8. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described back surface The thickness that passivation layer is is 50～80nm.

9. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described back surface Passivation layer is SiN_xFilm layer, SiO₂/Si₃N₄Stack membrane, SiO₂/Al₂O₃/Si₃N₄Stack membrane, Al₂O₃/Si₃N₄ Any one in stack membrane.

10. all back-contact electrodes solaode as claimed in claim 1, it is characterised in that described battery The width of positive pole is 45～80um, and the width of described battery cathode is 45～80um.