10
nanotimes Research
11-08 :: August 2011
Solar Cells II // Long-Term-Stable Copper Metallization and Industrially
Feasible Processes Have Enabled 21.4% Efficiency © Text: Fraunhofer ISE
R
eductions in the electricity generation costs for photovoltaics can be reached through two
mechanisms: improving the efficiency of solar cells and reducing their production costs. With advanced processes for metallization of solar cells, both effects can be reached at the same time. In the ETAlab®
at
Fraunhofer ISE, Germany, the technology of produ- cing solar cell contacts 100% from low-cost materials has been achieved. In doing so, industrially feasible galvanic processes were used and expensive silver has been replaced, mostly by copper. The resear- chers achieved a solar cell efficiency of 21.4% using this approach. Especially remarkable: this result is comparable with values from solar cells using a highly efficient titanium/palladium/silver contact system, which must be created in comparatively expensive vacuum laboratory processes.
An efficiency potential for solar cells is provided by the galvanic nickel-copper system with direct de- position to silicon, without a printed silver contact layer. Using an industrially feasible process, such as laser ablation, the anti-reflection coating (ARC) is removed locally. Structural widths in the range of 20µm are achieved, which significantly reduces shading in comparison to screen printing. In the affected areas of the ARC, nickel will be selectively deposited, which is then reinforced and made sol-
“Our copper-metallized solar cells from the ETAlab® are not only comparable with the efficiency of the titanium/palladium/silver reference technology, but also show an excellent stability in long-term tests. A thermal stress test of 1600 hours at 200° C (392° F) had no consequences for the efficiency,” says Jonas Bartsch, Team Leader “Plating Process Technology”.
With the process knowledge built up at Fraunhofer ISE, the researchers at the ETAlab®
are working on transferring this technology to large solar cell formats.
derable by the addition of copper and zinc or silver. On solar cells with front and rear side passivation in a 2x2 cm² format, this technology reached an effici- ency of 21.4% in ETAlab®
, which was confirmed by CalLab PV Cells at Fraunhofer ISE.
Contact: Fraunhofer Institute for Solar Energy Systems ISE, Jonas Bartsch, Phone: +49 (0) 7 61 / 45 88 - 55 61
Dr. Markus Glatthaar, Phone: +49 (0) 7 61 / 45 88 - 52 72
http://www.ise.fraunhofer.de
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103