CN206628492U

CN206628492U - Solar cell

Info

Publication number: CN206628492U
Application number: CN201720301277.7U
Authority: CN
Inventors: 周仰皓; 周芳儀; 潘赠傑; 廖重期; 林国隆
Original assignee: Gintech Energy Corp
Current assignee: Gintech Energy Corp
Priority date: 2017-03-27
Filing date: 2017-03-27
Publication date: 2017-11-10
Anticipated expiration: 2027-03-27

Abstract

Solar cell, comprising：Semiconductor substrate, there is a preceding surface and a lower surface relative to surface before this；One emitter layer is located on preceding surface；One first passivation layer, on emitter layer；Multiple back surface electric field regions, at each interval on lower surface；One second passivation layer, on the back surface of semiconductor substrate, this second passivation layer has multiple openings, and wherein this second passivation layer includes at least two layers of stackable unit, and each stackable unit is formed by least two materials；Multiple first electrodes, it is arranged on this first passivation layer；With a second electrode, it is arranged on this second passivation layer, and contacts these back surface electric field regions through this second passivation layer via these openings respectively.Internal energy exponent number amount is reduced per layer of material characteristic by the second passivation layer, and forms back side reversed electric field to make carrier away from complex centre, while the refractive index using material in itself, allow reflection characteristic to optimize, improving luminous efficiency.

Description

Solar cell

Technical field

The utility model is on a kind of solar cell, and in particular to a kind of high power solar cell.

Background technology

In recent years, as environmental consciousness is surging and the shortage of fossil energy, alternative energy source has become heat with the renewable sources of energy The subject under discussion of door.Solar cell can convert solar energy into electric energy, and will not be produced during opto-electronic conversion carbon dioxide or The environmentally harmful material such as nitride, therefore, solar cell turn into renewable sources of energy research in recent years on it is quite important and by The ring welcome.

In general, solar cell includes active layers and is configured at the electrode layer of the offside of active layers two.When light beam shines When being incident upon solar cell, active layers can be produced electron-hole pair by the effect of luminous energy.Electricity is made by electric field between two electrode layers Son moves toward two electrode layers respectively with hole, and produces the storage form of electric energy.If now applied load circuit, electricity can be exported Can and drive electronics.

At present solar module because power output it is limited, and be difficult to provide family and the required electric power of industry.Therefore The power output of solar module how is lifted, is become as the trend in future.

Utility model content

The one technology aspect of this disclosure is to provide a kind of high power solar cell, this solar cell, comprising： Semiconductor substrate, there is a preceding surface and the back surface relative to the preceding surface；One emitter layer, positioned at the preceding surface； One first passivation layer, on the emitter layer；Multiple back surface electric field regions, at each interval positioned at the back surface；One second is blunt Change layer, on the back surface of the semiconductor substrate, second passivation layer has multiple openings, wherein the second passivation layer bag At least two layers of stackable unit is included, each stackable unit is formed by least two materials；Multiple first electrodes, be arranged at this On one passivation layer；And a second electrode, be arranged on second passivation layer, and respectively via the multiple opening through this Two passivation layers and contact the multiple back surface electric field region.

In an embodiment of this disclosure, semiconductor substrate is monocrystalline silicon substrate, polycrystalline silicon substrate or amorphous silicon substrate Plate.

In an embodiment of this disclosure, this at least two material comprise at least+2 to+4 valencys metal oxide or Nitride, and refractive index is between 1~3.

In an embodiment of this disclosure, each stackable unit also includes a first layer, a second layer and one the Three layers sequentially stack form.

In an embodiment of this disclosure, this first layer is aluminum oxide (Al₂O₃) layer, this second layer be titanium dioxide (TiO₂) layer and this third layer be zirconium nitride (Zr₄N₃) layer.

In an embodiment of this disclosure, first layer is alumina layer, zinc oxide film or zirconia layer.

In an embodiment of this disclosure, the second layer is alumina layer, titanium dioxide zirconium layer, titanium dioxide layer, oxidation Zirconium layer, silicon nitride layer or zirconium nitride layer.

In an embodiment of this disclosure, third layer is alumina layer, titanium dioxide zirconium layer, titanium dioxide layer, oxidation Zirconium layer, silicon nitride layer or zirconium nitride layer.

In an embodiment of this disclosure, each first layer, the second layer and the third layer thickness are 1nm- 10nm。

In an embodiment of this disclosure, stackable unit Al_xTi_yZr_zO_mN_tStackable unit, the Al_xTi_yZr_zO_mN_t Every kind of element wt ratio at least accounts for the Al in stackable unit_xTi_yZr_zO_mN_tThe material gross weight more than 10% of stackable unit, and entirely Portion's element wt ratio and for 100%.

In summary, the utility model is to form the second of solar cell back surface the passivation by multilayer lamination structure Layer, reduced by every layer of material characteristic in this multilayer lamination structure internal time can exponent number amount, and the formation back side is reverse Electric field makes carrier away from complex centre, while the refractive index using material in itself, allows reflection characteristic to optimize, improving luminous efficiency.

Brief description of the drawings

Fig. 1 show the skeleton diagram according to the embodiment solar cell of the utility model one；

Fig. 2 show the skeleton diagram according to the single stackable unit of the second passivation layer of embodiment of the utility model one.

Embodiment

Passivation emitter-base bandgap grading back electrode cell is to replace whole back aluminium alloy contact using back point contact, it is characterised in that There is passivation layer (Passivation) on the preceding surface of battery and back surface.Wherein, have at least in formation passivation layer on back surface Following benefits, except can directly reduce internal energy exponent number amount, and formation back side reversed electric field makes carrier away from complex centre Outside, the refractive index of material in itself more is used using formation passivation layer, allows reflection characteristic to optimize so that the light after reflection is more It is easy to be absorbed by solar cell substrate.Therefore the utility model is the stacked architecture design or mixing using passivation layer Design of material, each layer of passivation layer allowed in stacked architecture have an above-mentioned wherein at least feature, improving luminous efficiency.

Fig. 1 show the skeleton diagram according to the embodiment solar cell of the utility model one.As shown in figure 1, solar-electricity Pond 10 includes：Semiconductor substrate 11, one first passivation layer 12, one second passivation layer 13, multiple first electrodes 14, one second electricity Pole 15, local back surface field 16 (Back Surface Field, BSF).In one embodiment, solar cell 10 is one blunt Change the battery types of emitter-base bandgap grading back electrode cell (Passivated Emitter and Rear Cells, PERC).Wherein semiconductor Substrate 11 includes the preceding surface F and one of a light relative to the back surface R of the preceding surface F, the preceding surface F of semiconductor substrate 11 Concavo-convex texture (Texturing) is formed, reduces the reflectivity of incident light whereby.And in a manner of dopant and using thermal diffusion In forming emitter layer 111 (Emitter Layer) in the preceding surface F of semiconductor substrate 11, wherein emitter layer 111 coordinates preceding surface F The pattern that height rises and falls is configured in preceding surface F, and (the pn of pn junctions 101 is formed between semiconductor substrate 11 and emitter layer 111 junction).Semiconductor substrate 11 can be monocrystal material (single crystalline material), polycrystalline material (polycrystalline material) or non-crystalline material (amorphous material) are formed.In an embodiment, The essence of semiconductor substrate 11 can be monocrystalline silicon (single crystalline silicon), polysilicon (polycrystalline Silicon) or non-crystalline silicon (amorphous silicon) material.Semiconductor substrate 11 can utilize the crystalline substance of N-type or p-type base material Circle is formed.By taking p-type wafer as an example, N-type can be formed in the heavy doping of semiconductor substrate 11 (heavily dope) donor (donor) (N+) emitter layer 111.

First passivation layer 12 be arranged on emitter layer 11 as anti-reflecting layer (Anti-Reflection Coating, ARC), the first passivation layer 12 can be by silica (silicon dioxide), silicon nitride (silicon nitride) or oxidation The passivating materials such as aluminium (aluminum oxide) are formed.And first passivation layer 12 can surface treated, with the first passivation layer 12 Surface form various sizes of pyramid (pyramid) construction, pass through the machine that turns back of first reflection to reduce incident light Rate simultaneously protects emitter layer 11.Thereafter, the second passivation layer 13 is arranged on back surface R.In one embodiment, it is by repeatedly stacking one Stackable unit 17 forms this second passivation layer 13, and wherein this stackable unit 17 is formed by least two kinds of different materials, And the stacking number of this stackable unit 17 is at least 2 layers.

Fig. 2 show the skeleton diagram according to the single stackable unit of the second passivation layer of embodiment of the utility model one.It is real herein Apply in example, be by taking trilaminate material as an example, to illustrate the utility model.This single stackable unit 17 includes first layer 171, the second layer 172 and third layer 173.Wherein first layer 171 is formed in the layer on semiconductor substrate 11, for example, can contact in semiconductor Substrate 11.The second layer 172 is formed in the layer on first layer 171, for example, accessible first layer 171.Third layer 173 is to be formed Layer on the second layer 172, for example, the accessible second layer 172.Wherein, first layer 171, the second layer 172 and third layer 173 It is 1nm-10nm per thickness degree.Because first layer 171 is formed in the layer on semiconductor substrate 11, in order to directly reduce internal time Energy exponent number amount, therefore the main optimal material for selecting passivated surface complex centre (Recombination Center).And the Two layer 172 and third layer 173 make field effect passivation (field effect from the optimal material of fixed charge density characteristic Passivation, FEP) effect is most strong.Wherein selected material+2 arrives the metal oxide or nitride and refractive index n of+4 valencys Between 1~3.In one embodiment, the material of first layer 171 is aluminum oxide, and the material of the second layer 172 is titanium dioxide, third layer 173 materials are zirconium nitride, and form Al₂O₃/TiO₂/Zr₄N₃Stackable unit 17., can be because of it using aluminum oxide under this framework The presence of fixed negative charge, and it is used for the passivation of titanium dioxide, titanium dioxide gives birth to sky because irradiation produces electron hole pair Cave is because the negative electrical charge of aluminum oxide attracts, and past Al₂O₃/TiO₂Junction is close, and electronics then can be close toward center away from surface, Electron hole separates, so that it may reduces compound chance, lifts the life-span (lifetime) of carrier, therefore has preferable opto-electronic conversion Efficiency.It is worth noting that, the second layer 172 and material selected by third layer 173 can be with identical, but first layer 171 and Two layer 172 and the material selected by third layer 173 it is different.It is worth noting that, first layer 171, the second layer 172 and third layer Material selected by 173 is not limited with above-mentioned, and in another embodiment, the material of first layer 171 can be selected as aluminum oxide, zinc oxide One of with zirconium oxide.The second layer 172 and the material of third layer 173 can be selected aluminum oxide, zirconium dioxide, titanium dioxide, One of zirconium oxide, silicon nitride and zirconium nitride.And in another embodiment, a stackable unit 17 is by a mixing material institute shape Single layer architecture, this mixing material is Al_xTi_yZr_zO_mN_t, every kind of element wt ratio at least accounts for the mixing wherein in mixing material Material gross weight more than 10%, and whole element wts ratio and for 100%.

Afterwards, connect using laser or etching paste with forming electrode in forming multiple openings 18 on the second passivation layer 13 Point, preceding surface F and back surface R then at semiconductor substrate 11 carry out metal coating (Metallization), and are burnt jointly (Co-Firing) program is tied, multiple first electrodes 14 are formed with the preceding surface F in semiconductor substrate 11, and in semiconductor substrate 10 back surface R, which is adjacent at opening 18, to be formed local back surface field 16 (Back Surface Field, BSF) and is covered in Second electrode 15 on the passivation layer 13 of opening 18 and second, is passivated the manufacture of emitter-base bandgap grading back electrode cell with completion whereby.Wherein Two electrodes 15 can contact local back surface field 16 via these openings 18 through the second passivation layer 13 respectively.

The utility model is the second passivation layer that solar cell back surface is formed by multilayer lamination structure, passes through this Every layer of material characteristic in multilayer lamination structure come reduce internal time can exponent number amount, and form back side reversed electric field and make carrier Away from complex centre, while the refractive index using material in itself, allow reflection characteristic to optimize so that the light after reflection be easier to by Solar cell substrate is absorbed, improving luminous efficiency.

Although this disclosure is disclosed above with embodiment, so it is not limited to this disclosure, any ripe This those skilled in the art is known, in the spirit and scope for not departing from this disclosure, when can be used for a variety of modifications and variations, therefore this announcement The protection domain of content is worked as to be defined depending on the scope of which is defined in the appended claims.

Claims

1. a kind of solar cell, it is characterised in that include：

Semiconductor substrate, there is a preceding surface and the back surface relative to the preceding surface；

One emitter layer, positioned at the preceding surface；

One first passivation layer, on the emitter layer；

Multiple back surface electric field regions, at each interval positioned at the back surface；

One second passivation layer, on the back surface of the semiconductor substrate, second passivation layer has multiple openings, wherein should Second passivation layer includes at least two layers of stackable unit, and each stackable unit is formed by least two materials；

Multiple first electrodes, it is arranged on first passivation layer；And

One second electrode, be arranged on second passivation layer, and respectively via the multiple opening through second passivation layer and Contact the multiple back surface electric field region.

2. solar cell according to claim 1, it is characterised in that wherein the semiconductor substrate be monocrystalline silicon substrate, Polycrystalline silicon substrate or amorphous silicon substrate.

3. solar cell according to claim 1, it is characterised in that wherein at least two material arrives including at least+2 The metal oxide or nitride of+4 valencys, and refractive index is between 1~3.

4. solar cell according to claim 1, it is characterised in that stackable unit described in each of which also includes one the One layer, a second layer and a third layer are sequentially stacked and formed.

5. solar cell according to claim 4, it is characterised in that wherein the first layer be alumina layer, this second Layer is titanium dioxide layer and the third layer is zirconium nitride layer.

6. solar cell according to claim 4, it is characterised in that wherein the first layer is alumina layer, zinc oxide Layer or zirconia layer.

7. solar cell according to claim 4, it is characterised in that wherein the second layer is alumina layer, titanium dioxide Zirconium layer, titanium dioxide layer, zirconia layer, silicon nitride layer or zirconium nitride layer.

8. solar cell according to claim 4, it is characterised in that wherein the third layer is alumina layer, titanium dioxide Zirconium layer, titanium dioxide layer, zirconia layer, silicon nitride layer or zirconium nitride layer.

9. solar cell according to claim 4, it is characterised in that each of which first layer, the second layer and The third layer thickness is 1nm-10nm.

10. solar cell according to claim 1, it is characterised in that wherein the stackable unit is Al_xTi_yZr_zO_mN_tHeap Folded unit, the Al_xTi_yZr_zO_mN_tEvery kind of element wt ratio at least accounts for the Al in stackable unit_xTi_yZr_zO_mN_tThe material of stackable unit Expect gross weight more than 10%, and whole element wts ratio and for 100%.