CN201126823Y

CN201126823Y - Laminate solar battery

Info

Publication number: CN201126823Y
Application number: CN 200720172723
Authority: CN
Inventors: 李毅; 徐祥福
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-10-25
Filing date: 2007-10-25
Publication date: 2008-10-01
Anticipated expiration: 2017-10-25

Abstract

The utility model relates to a tandem solar cell, comprising integrated a plurality of photoelectric units serially connected. Each unit consists of insulation substrate, front electrode, intermediate transparent conductive film, photo-electric conversion layer and back electrode, which also comprises connecting wires between positive and negative electrodes of adjacent photoelectric units; the each photoelectric unit is provided with more than two parallelly-superimposed photo-electric conversion layers with intermediate transparent conductive film interbedded therebetween; the front electrode, intermediate transparent conductive film, photo-electric conversion layer and the back electrode are respectively provided with corresponding channels. The tandem solar cell of the utility model solves problem of current mismatch for two subcells, and also can meet requirements of high current and low voltage in some fields.

Description

A kind of lamination solar cell

Technical field

The utility model relates to a kind of lamination solar cell, belongs to thin-film solar cells and makes the field.

Background technology

The relative crystal silicon solar energy battery of non-crystal silicon solar cell or other solar cell have stronger absorption to visible light, but its shortcoming is to have the photo attenuation effect.In order to weaken this effect, adopt many knot laminated construction at present, promptly be the two-layer or Heterolamellar photovoltaic conversion layer of stack, the photoelectric conversion layer of stack can be an identical materials, as all being the amorphous silicon material, or different material, as amorphous silicon of amorphous silicon-polysilicon, amorphous silicon-doped germanium, carbon or fluorine etc., laminated construction had both improved the spectral absorption scope of having expanded, and had improved efficiency of light absorption, but also increased life-span of solar cell, weakened the photo attenuation effect.General laminated cell adopts the PIN-PIN structure, is equivalent to two sub-batteries are together in series, though this battery can improve conversion efficiency, weakens the photo attenuation effect, and there is the currents match problem in two sub-batteries of series connection.At present, on production technology, no matter be the solar cell of homojunction or heterojunction, the electric current that makes each sub-battery by the thickness of controlling each sub-battery is near coupling, but under different intensities of illumination, different spectrum, the currents match state of solar cell will be different, can not reach coupling fully during use.

Simultaneously, two sub-batteries are connected, and can increase the pressure of holding of battery, but in some applications, for example solar-powered photovoltaic curtain wall needs solar panel that relatively large electric current is provided.In using at present, can only reduce grid joint number order, increase each grid nodal section and amass and realize, but can bring solar panel " large tracts of land effect " like this, promptly increase area, will reduce conversion efficiency.

U.S. Pat 4948436 " Thin-film solar cell arrangement " discloses a kind of lamination solar cell, its structure as shown in Figure 4, the design of this invention is that laminated cell adopts mode in parallel, and the mode that use is connected between the joint of battery and the joint.Laminated cell realizes that parallel connection is to adopt the sedimentary sequence different with traditional lamination, and it is preceding electrode 2, P1 layer 3, I1 layer 4, N layer 5 in proper order, I2 layer 6, P2 layer 7, back electrode 8, two sub-battery sharing N layers.Battery joint with save between mode by laser grooving realize connecting, two steps 17,19 of electrode 2 and N layer 5 before in laser grooving, making respectively, remainder except that the back electrode 8 of step part and back one batteries in the groove is insulated with insulating material 20, and fill laser grooving with electric conducting material 21, adopt this mode, the N layer 5 of last batteries, the negative pole that is battery links to each other with back electrode 8 by the preceding electrode 2 of electric conducting material 21 with back one batteries, thus connecting between realizing the battery joint and saving.But this scheme requires to cover one deck insulating material at an end of film, and must guarantee to expose two steps 17,19, and its machining accuracy height if widen laser grooving, will reduce the effective area of solar cell.

The utility model content

By the above, the purpose of this utility model is the electric current mismatch problem that solves two straton batteries in the existing laminated cell, and a kind of solar cell that can realize big electric current, low-voltage is provided.

The technical solution adopted in the utility model is a kind of lamination solar cell of research, comprise: the integrated photovoltaic element that several are cascaded, each photovoltaic element is made up of dielectric substrate, preceding electrode, central, clear conducting film, photoelectric conversion layer, back electrode, and comprises the connecting line of positive and negative electrode between the adjacent light electric unit; Described each photovoltaic element has the photoelectric conversion layer of two stacks parallel with one another at least, and the central, clear conducting film is clipped between two photoelectric conversion layers; Preceding electrode, central, clear conducting film, photoelectric conversion layer, back electrode are respectively equipped with corresponding raceway groove.

As a kind of preferred version, described photoelectric conversion layer is made up of an amorphous silicon P-I-N photoelectric conversion layer and an amorphous silicon N-I-P photoelectric conversion layer stack in parallel.

As another preferred version, the positive and negative electrode connecting line constitutes by filling the back electrode material in the raceway groove of filling electrically conducting transparent membrane material and N-I-P photoelectric conversion layer in the raceway groove of P-I-N photoelectric conversion layer.

The raceway groove that further preferred scheme is described N-I-P photoelectric conversion layer be positioned at the P-I-N photoelectric conversion layer raceway groove vertically directly over, width is less than 0.1mm.

Before another preferred version, the isolating trenches of back electrode are positioned at the raceway groove of electrode vertically directly over, width is less than 0.1mm.

Another preferred version, the spacing between the raceway groove of photoelectric conversion layer and the raceway groove of preceding electrode is 0.1～0.3mm.

Another preferred version, central, clear conducting film are to be made by zinc oxide, tin oxide or ITO material.

The beneficial effects of the utility model are electric current mismatch problems of having avoided two sub-batteries, and can satisfy the demand of big electric current, low-voltage in some occasion.In addition, the lamination solar cell that utility model provides is compared with U.S. Pat 4948436 lamination solar cells, not only simple in structure, and the isolating trenches of back electrode be positioned at before electrode raceway groove vertically directly over, improved the effective area of solar cell effectively.

Description of drawings

Fig. 1 is the sectional view of lamination solar cell of the present utility model;

Fig. 2 is the both positive and negative polarity connection diagram of the utility model lamination solar cell;

Fig. 3 is the equivalent circuit diagram of solar battery structure described in the utility model;

Fig. 4 is U.S. Pat 4948436 disclosed a kind of lamination solar cell structure charts.

Among Fig. 1,26 is glass substrate; 27 is preceding electrode; Top battery 28 is a P-I-N amorphous silicon photoelectric conversion layer; 28-1 is the P layer of top battery; 28-2 is the I layer of top battery; 28-3 is the N layer of top battery; 29 is the central, clear conducting film; End battery 30 is a N-I-P amorphous silicon photoelectric conversion layer; 30-1 is the N layer of end battery; 30-2 is the I layer of end battery; 30-3 is the P layer of end battery; 31 is back electrode; 32 is the raceway groove of end battery; 33 is the raceway groove of top battery; 34 is the raceway groove of preceding electrode; 35 is the raceway groove of back electrode; 36 is the raceway groove of central, clear conducting film; 37,38 is two adjacent batteries.

In conjunction with Fig. 2 the principle of lamination solar cell is described, at first sunshine passes transparent by glass substrate 26 The front electrode 27 of conduction incides the top battery, and top battery absorbent portion light splitting changes electric energy into. Front electrode with The P layer 28-1 of top battery links to each other, and is the positive pole of top battery; Nesa coating 29 and top battery N layer 28-2 Link to each other, be the negative pole of top battery. The part sunshine that is not absorbed by the top battery incides end battery, the end The N layer 30-1 of battery links to each other with nesa coating 29, is the negative pole of end battery, back electrode 31 and end battery P layer 30-3 link to each other, be the positive pole of end battery. The negative pole of two sub-batteries links to each other by nesa coating 29, The anodal raceway groove 32,33 that passes through links to each other, thereby realizes two sub-cell parallels. The negative pole of front batteries 37 with The positive pole of rear batteries 38 joins, and has also just realized connecting of joint and batteries.

Fig. 4 is the lamination solar cell sectional view of U.S. Pat 4948436, as shown in Figure 4, and the U.S. The lamination solar cell of patent US4948436 adopts mode in parallel, and uses between the joint of battery and the joint The mode of series connection. Laminated cell realizes that parallel connection is to adopt the sedimentary sequence different from traditional lamination, and it is in proper order Front electrode 2, P1 layer 3, I1 layer 4, N layer 5, I2 layer 6, P2 layer 7, back electrode 8, two sub-batteries are altogether Use the N layer. Battery joint with save between mode by laser grooving realize connecting, in laser grooving, do respectively Go out two steps 17,19 of front electrode 2 and N layer 5, will remove the back of the body of step part and a rear batteries in the groove Remainder outside the electrode 8 insulate with insulating materials 20, and fills laser groovings with conductive material 21, Adopt this mode, the N layer 5 of last batteries, namely the negative pole of battery is by conductive material 21 and a rear joint The front electrode 2 of battery links to each other with back electrode 8, thus connecting between realizing the battery joint and saving.

Specific embodiment

As shown in Figure 2, the lamination solar cell that the utility model provides, perpendicular to direction, its structure is: glass substrate 26, preceding electrode 27, top battery 28, nesa coating 29, end battery 30, back electrode 31.Adopt this structure, two sub-battery cathode of laminated cell are linked to each other, and anodal continuous by the raceway groove on two

sub-batteries

32,33, the parallel connection of promptly having reached laminated cell.The N layer of each sub-battery be negative pole promptly the negative pole of two sub-batteries link to each other by nesa coating 29, and preceding electrode 27, back electrode 31 link to each other with the anodal P layer of each sub-battery; Preceding electrode 27 is led film 29 by raceway groove 33 and central, clear and is linked to each other, back electrode 31 links to each other with central, clear conducting film 29 by raceway groove 32, the negative pole of last like this batteries is by central, clear conducting film 29, link to each other with back electrode 31 with the preceding electrode 27 of next batteries, promptly link to each other, thereby reached joint and being connected in series of saving with the positive pole of next batteries.

The principle of lamination solar cell is described in conjunction with Fig. 2: at first sunlight passes electrode 27 before the nesa coating by glass substrate 26, incides the top battery, and top battery absorbent portion beam split changes electric energy into.Preceding electrode links to each other with the P layer 28-1 of top battery, is the positive pole of top battery; Central, clear conducting film 29 links to each other with top battery N layer 28-3, is the negative pole of top battery.The part sunlight that is absorbed by the top battery does not incide end battery, and the N layer 30-1 of end battery links to each other with central, clear conducting film 29, is the negative pole of end battery, and back electrode 31 links to each other with the P layer 30-3 of end battery, is the positive pole of end battery.The negative pole of two sub-batteries links to each other by nesa coating 29, and is anodal continuous by

raceway groove

32,33, thereby realizes two sub-battery parallel connections.Before the positive pole of negative pole and back batteries 38 of batteries 37 join, also just realized connecting of joint and batteries.

Fig. 3 is the equivalent circuit diagram of the utility model lamination solar cell central layer.If regard the single-unit solar cell as a photodiode, structure so of the present invention is equivalent to two

photodiodes

22,23 or 24,25 are connected in parallel, and then integral body is cascaded.

The production process of the lamination solar cell that the utility model provides is as follows:

Step 1, depict with the infrared light laser before the raceway groove 34 of electrode 27;

Step 2, use CVD method deposit top battery 28 on preceding electrode 27, promptly deposit P layer 28-1, I layer 28-2, the N layer 28-3 of top battery successively;

Step 3, use green (light) laser carve the raceway groove 33 of top battery, and width is less than 0.1mm; Distance between the raceway groove 33 of top battery and the raceway groove 34 of preceding electrode 27 is 0.1～0.3mm;

The method of step 4, use sputter prepares one deck central, clear conducting film 29, adopts the mask line to prepare the raceway groove 36 of central, clear conducting film 29 simultaneously;

Step 5, deposit N layer 30-1, I layer 30-2, the P layer 30-3 of end battery successively again;

Step 6, utilize the raceway groove 32 of green (light) laser delineation end battery, width is less than 0.1mm;

Step 7, utilize the method for evaporation to prepare back electrode 31, adopt the mask line to prepare the raceway groove 35 of back electrode 31 simultaneously.

Claims

1, a kind of lamination solar cell, comprise: the integrated photovoltaic element that several are cascaded, it is characterized in that each photovoltaic element is made up of dielectric substrate, preceding electrode, central, clear conducting film, photoelectric conversion layer, back electrode, and comprise the connecting line of positive and negative electrode between the adjacent light electric unit; Described each photovoltaic element has the photoelectric conversion layer of two stacks parallel with one another at least, and the central, clear conducting film is clipped between two photoelectric conversion layers; Preceding electrode, central, clear conducting film, photoelectric conversion layer, back electrode are respectively equipped with corresponding raceway groove.

2, lamination solar cell according to claim 1 is characterized in that described photoelectric conversion layer is made up of an amorphous silicon P-I-N photoelectric conversion layer and the stack in parallel of amorphous silicon N-I-P photoelectric conversion layer.

3, lamination solar cell according to claim 1 is characterized in that the positive and negative electrode connecting line constitutes by filling the back electrode material in the raceway groove of filling electrically conducting transparent membrane material and N-I-P photoelectric conversion layer in the raceway groove of P-I-N photoelectric conversion layer.

4, lamination solar cell according to claim 3, the raceway groove that it is characterized in that described N-I-P photoelectric conversion layer be positioned at the P-I-N photoelectric conversion layer raceway groove vertically directly over, width is less than 0.1mm.

5, lamination solar cell according to claim 1, before the raceway groove that it is characterized in that described back electrode is positioned at the raceway groove of electrode vertically directly over, width is less than 0.1mm.

6, lamination solar cell according to claim 1 is characterized in that the spacing between the raceway groove of the raceway groove of described photoelectric conversion layer and preceding electrode is 0.1～0.3mm.

7, lamination solar cell according to claim 1 is characterized in that described central, clear conducting film is to be made by zinc oxide, tin oxide or ITO material.