Fast compositional mapping of solar cell by laser spectroscopy technique for process monitoring

Abstract

The applicability of laser-induced breakdown spectroscopy (LIBS) for elemental mapping in atmospheric condition is demonstrated using a commercial Cu(In,Ga)Se2 solar cells module. The LIBS analysis was carried out using a Q-switched Nd:YAG laser (λ = 532 nm, τ = 5 ns, top-hat profile) and a CCD spectrometer. At the laser fluence of 22 J/cm2 with He as the buffer gas, a spatial resolution of 130 μm was achieved and the LIBS mapping of a 2.58 × 2.58 mm2 area was completed in 24 min. It is demonstrated that the detailed variation of elemental concentrations across the scribing pattern and over the buried pattern could be measured with LIBS. The comparison of measured LIBS profiles with those from secondary ion mass spectrometry agreed closely.