Conductive paste and conductive track or coating
地域：
London
摘要
The present invention relates to a conductive paste for forming a conductive track or coating on a substrate, particularly suitable for use in solar cells. The paste comprises a solids portion dispersed in an organic medium, the solids portion comprising electrically conductive material and an inorganic particle mixture wherein the inorganic particle mixture comprises substantially crystalline particles. The present invention also relates to a method of preparing a conductive paste, a method for the manufacture of a surface electrode of a solar cell, an electrode for a solar cell and a solar cell.
說(shuō)明書(shū)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
This application is the National Stage of International Patent Application No. PCT/GB2016/053484, filed Nov. 8, 2016, which claims priority from Great Britain Patent Application No. 1520060.3, filed Nov. 13, 2015, each of which applications is incorporated herein by reference in its entirety for any and all purposes.
The present invention relates to conductive pastes which are particularly suitable for use in solar cells and methods for making those pastes, to a method of manufacturing a conductive track or coating on a surface e.g. of a solar cell, and to a surface of a solar cell having a conductive track or coating formed thereon.
Screen printed conductive (e.g. silver) pastes are routinely used as conductive tracks for solar cells, such as silicon solar cells. The pastes typically comprise conductive (e.g. silver) powder, glass frit, and sometimes one or more additional additives, all dispersed in an organic medium. The glass frit has several roles. During firing, it becomes a molten phase and so acts to bond the conductive track to the semiconductor wafer. However, the glass frit is also important in etching away the anti-reflective or passivation layer (usually silicon nitride) provided on the surface of the semiconductor wafer, to permit direct contact between the conductive track and the semiconductor. The glass frit is typically also important in forming an ohmic contact with the semiconductor emitter.
權(quán)利要求
The invention claimed is:1. A conductive paste for forming a conductive track or coating on a substrate, the paste comprising a solids portion dispersed in an organic medium,the solids portion comprising electrically conductive material and an inorganic particle mixture; wherein the inorganic particle mixture comprises substantially crystalline particles of two or more different metal compounds and is substantially lead free; wherein the solids portion is glass free, wherein the inorganic particle mixture comprises a compound of tellurium, and wherein each one of the crystalline particles of the two or more different metal compounds contains only one metal element. 2. The conductive paste according to claim 1 , wherein the inorganic particle mixture comprises a compound of lithium. 3. The conductive paste according to claim 1 , wherein the electrically conductive material comprises one or more metals selected from silver, copper, nickel and aluminium. 4. The conductive paste according to claim 1 , wherein the solids portion includes 0.1 to 15 wt % of inorganic particle mixture. 5. The conductive paste according to claim 1 , wherein the solids portion includes 80 to 99.9 wt % of electrically conductive material. 6. The conductive paste according to claim 1 , wherein the particles of the inorganic particle mixture have a particle size distribution in which one or more of the following conditions applies:D10≤0.41 μm;??(a) D50≤1.6 μm;??(b) D90≤4.1 μm;??(c) (D50?D10)≤1.15 μm;??(d) (D90?D50)≤2.5 μm;??(e) (D90?D10)≤3.7 μm; or??(f) (D50/D10)≤3.85??(g). 7. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy the condition (b). 8. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy the condition (c). 9. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy the condition (d). 10. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy the condition (e). 11. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy the condition (f). 12. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy the condition (g). 13. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy D90≤2.2 μm. 14. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy D50≤1.05 μm. 15. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy D10≤0.4 μm. 16. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy D90?D10≤1.8 μm. 17. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy D90?D50≤1.15 μm. 18. A conductive paste according to claim 6 , wherein the particles of the inorganic particle mixture satisfy D50?D10≤0.6 μm. 19. A method of preparing a conductive paste comprising a solids portion dispersed in an organic medium, the solids portion comprising electrically conductive material and an inorganic particle mixture, wherein the inorganic particle mixture comprises substantially crystalline particles of two or more different metal compounds and is substantially lead free; wherein the solids portion is glass-free, and wherein the inorganic particle mixture comprises a compound of tellurium, and wherein each one of the crystalline particles of the two or more different metal compounds contains only one metal element,the method comprising: mixing the organic medium, the electrically conductive material, and the components of the inorganic particle mixture, in any order. 20. The method according to claim 19 , comprising co-milling the substantially crystalline particles of the inorganic particle mixture before they are mixed with the organic medium and the electrically conductive metal. 21. The method according to claim 19 , comprising milling each component of the inorganic particle mixture separately prior to mixing the organic medium, the electrically conductive material, and the components of the inorganic particle mixture. 22. A method for the manufacture of a surface electrode of a solar cell, the method comprising:applying, to a semiconductor substrate, a conductive paste comprising a solids portion dispersed in an organic medium, the solids portion comprising electrically conductive material and an inorganic particle mixture; wherein the inorganic particle mixture comprises substantially crystalline particles of two or more different metal compounds and is substantially lead free, wherein the solids portion is glass-free, wherein the inorganic particle mixture comprises a compound of tellurium, wherein each one of the crystalline particles of the two or more different metal compounds contains only one metal element, and firing the applied conductive paste. 23. An electrode for a solar cell, the electrode comprising a conductive track on a semiconductor substrate, wherein the conductive track is obtained or obtainable by firing, on the semiconductor substrate, a paste comprising a solids portion dispersed in an organic medium, the solids portion comprising electrically conductive material and an inorganic particle mixture;wherein the inorganic particle mixture comprises substantially crystalline particles of two or more different metal compounds and is substantially lead free, wherein the solids portion is glass-free, wherein the inorganic particle mixture comprises a compound of tellurium, and wherein each one of the crystalline particles of the two or more different metal compounds contains only one metal element. 24. A solar cell comprising a surface electrode, the surface electrode comprising electrode comprising a conductive track on a semiconductor substrate, wherein the conductive track is obtained or obtainable by firing, on the semiconductor substrate, a paste comprising a solids portion dispersed in an organic medium, the solids portion comprising electrically conductive material and an inorganic particle mixture; wherein the inorganic particle mixture comprises substantially crystalline particles of two or more different metal compounds and is substantially lead free, wherein the solids portion is glass-free, wherein the inorganic particle mixture comprises a compound of tellurium, and wherein each one of the crystalline particles of the two or more different metal compounds contains only one metal element.
意見(jiàn)反饋
使用該功能遇到問(wèn)題
該功能需要專(zhuān)業(yè)版企業(yè)版VIP權(quán)限，您可以：
您也可以聯(lián)系官方QQ: 2157717237 電話: 13264338900
PatentHub聯(lián)系方式
掃描加專(zhuān)利匯官方微信交流群
