title: CIGS thin-film solar module processing: case of high-speed laser scribing.
abstract: In this paper, we investigate the laser processing of the CIGS thin-film solar cells in the case of the high-speed regime. The modern ultra-short pulsed laser was used exhibiting the pulse repetition rate of 1 MHz. Two main P3 scribing approaches were investigated - ablation of the full layer stack to expose the molybdenum back-contact, and removal of the front-contact only. The scribe quality was evaluated by SEM together with EDS spectrometer followed by electrical measurements. We also modelled the electrical behavior of a device at the mini-module scale taking into account the laser-induced damage. We demonstrated, that high-speed process at high laser pulse repetition rate induced thermal damage to the cell. However, the top-contact layer lift-off processing enabled us to reach 1.7 m/s scribing speed with a minimal device degradation. Also, we demonstrated the P3 processing in the ultra-high speed regime, where the scribing speed of 50 m/s was obtained. Finally, selected laser processes were tested in the case of mini-module scribing. Overall, we conclude, that the top-contact layer lift-off processing is the only reliable solution for high-speed P3 laser scribing, which can be implemented in the future terawatt-scale photovoltaic production facilities.
authors.affiliation: Center for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300, Vilnius, Lithuania.
authors.forename: Paulius
authors.initials: P
authors.lastname: Gečys
authors.affiliation: Center for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300, Vilnius, Lithuania.
authors.forename: Edgaras
authors.initials: E
authors.lastname: Markauskas
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Swiss Federal Laboratories for Materials Science and Technology EMPA, Ueberlandstrasse 129, CH-8600 Duebendorf, Switzerland.
authors.forename: Shiro
authors.initials: S
authors.lastname: Nishiwaki
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Swiss Federal Laboratories for Materials Science and Technology EMPA, Ueberlandstrasse 129, CH-8600 Duebendorf, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Buecheler
authors.affiliation: Next Scan Technology, Noorwegenstraat 29, 9940 Evergem, Belgium.
authors.forename: Ronny
authors.initials: R
authors.lastname: De Loor
authors.affiliation: Bern University of Applied Sciences, Pestalozzistrasse 20, CH-3400 Burgdorf, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Burn
authors.affiliation: Bern University of Applied Sciences, Pestalozzistrasse 20, CH-3400 Burgdorf, Switzerland.
authors.forename: Valerio
authors.initials: V
authors.lastname: Romano
authors.affiliation: Center for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300, Vilnius, Lithuania.
authors.forename: Gediminas
authors.initials: G
authors.lastname: Račiukaitis