Indirect ablation of Cu(In, Ga)Se2-layers by ns pulses with a wavelength of 1342 nm

Indirect ablation of thin layers from a substrate (lift-off) is a commonly known alternative to direct ablation. Since energy deposition takes place at the interface between thin film and substrate the thin film itself and especially the resulting scribe edges are less affected by laser irradiation which reduces the probability of thermally induced damage. We show that 10 ns pulses at 1342 nm are capable to remove CIGS layers from the Mo substrate. The experimental results are backed up by an optical thermal model based on the one dimensional heat equation which was modified to include the laser absorption.