In thin-film silicon photovoltaic modules the laser scribing processes are optimised to achieve low-loss performance of the segment interconnections. The characterisation of the component scribes and the contribution of the interconnect structure to the initial, degraded and low illumination performance of the module are described. Scribing processes based on nanosecond (ns) pulse duration lasers that are irradiated from the substrate side have been studied. These through-theglass (TTG) processes use selective laser wavelengths for targeted removal of the different layers in the photovoltaic cell structure. It is shown that wide process windows exist for the three laser scribing processes in the interconnect structure, with well defined behaviour at the limits of each process. In a second part of this paper, initial studies have been made on scribing processes using lasers with picosecond (ps) pulse durations with irradiation from the deposition layer side of the module. This 'top-scribe' approach allows a single wavelength for all three scribing processes and the high power ps laser sources now available can support scribe processing speeds of up to 120 m/min. The interaction between the ps laser and processed layers is characterised to derive the process ablation fluences and initial scribe process window parameters.

Date Published: 13 September 2011
PDF: 15 pages
Proc. SPIE 8110, Thin Film Solar Technology III, 811013 (13 September 2011); doi: 10.1117/12.893453

Published in SPIE Proceedings Vol. 8110:
Thin Film Solar Technology III
Louay A. Eldada, Editor(s)