O. Haupt
A. Schoonderbeek
L. Richter
R. Kling
A. Ostendorf

A new process for laser edge isolation of crystalline solar cells

European Photovoltaic Solar Energy Conference (EU PVSEC)
1.-5. September
Valencia
2010
Type: Konferenzbeitrag
Abstract
We developed a novel laser process which can be used for edge isolation of crystalline solar cells without any damage to the active area. Today laser edge isolation processes cause damage to the material and the deposited material reduces the efficiency by shadowing the active area. Generally, all processes use the mechanism of ablating where the silicon is melted or vaporized along a path around the solar cell. The new process separates a small strip around the solar cell by using thermally induced stress. This is possible by heating the material in an uncritical temperature range where silicon deforms elastically. Due to the homogeneous edge, the fracture strength increases which creates less faulty specimens. This effect is especially applicable for the trend of producing thinner solar cells in the near future. In this paper, experimental investigations for the new thermally induced separating process will be shown. The achieved edge quality is compared with conventional laser ablation processes by using a three-point bending test.