Optimization of the structuring processes of CI(G)S thin-film solar cells with an ultrafast picosecond laser and a special beam shaping optics

Abstract

Low cost CuIn(Ga)Se2 (CI(G)S), CdTe and GaAs thin-film solar cells with photosensitive film thicknesses in the range of a few microns – either on thick flat glass substrates or thin flexible substrates like plastic or metal foils – are gaining ground in the solar cell market compared to the traditional and expensive Si solar cells. We report on the optimization of the different structuring processes (P1, P2 and P3 structuring) of CI(G)S thin-film solar cells regarding process speed, structuring quality and efficient ablation strategies with a special beam shaping optics and an ultrafast picosecond laser system. The structured samples were optically analyzed using stereo and confocal microscopes. The ablation structures obtained with the picosecond laser system are compared with the mechanical structuring processes using fine metal needles for high volume production of thin-film solar cells and modules.Low cost CuIn(Ga)Se2 (CI(G)S), CdTe and GaAs thin-film solar cells with photosensitive film thicknesses in the range of a few microns – either on thick flat glass substrates or thin flexible substrates like plastic or metal foils – are gaining ground in the solar cell market compared to the traditional and expensive Si solar cells. We report on the optimization of the different structuring processes (P1, P2 and P3 structuring) of CI(G)S thin-film solar cells regarding process speed, structuring quality and efficient ablation strategies with a special beam shaping optics and an ultrafast picosecond laser system. The structured samples were optically analyzed using stereo and confocal microscopes. The ablation structures obtained with the picosecond laser system are compared with the mechanical structuring processes using fine metal needles for high volume production of thin-film solar cells and modules.