title: Micro-structuring of CIGS thin-film coated on Mo back contact by ultrafast laser 'rail-roading' patterning.
abstract: We report selective patterning process, laser 'rail-roading' scribing method, of which operating principle is based on transient force balance between the material properties including cohesion and adhesion forces subjected to underlying substrate and laser-induced shock compression and shear forces. By using dual fs-laser beam lines with an interval larger than laser spot size, we provide a proof of the concept by patterning the photovoltaic modules based on CIGS (Cu(In,Ga)Se2) coated on Mo electrode. With varying the interval between the two laser beam tracks, we can provide intact Mo back contact surface without any residues in a manner of more facile, high-speed and high scribing efficiency. We have interpreted the effect of the ambient gases and grooving width on the scribing performance in terms of the cohesion forces between the grains of CIGS thin films as well as adhesion force between underlying Mo layer and CIGS, which are mainly governed by local laser ablation and peening process followed by laser-induced shock compression, respectively.
authors.affiliation: Division of Convergence Technology, Korea Research Institute of Standards and Science, Doryong-Dong, Yuseong-Gu, Daejeon, Korea. scjeoung@kriss.re.kr
authors.forename: Sae Chae
authors.initials: SC
authors.lastname: Jeoung
authors.forename: Heung-Soon
authors.initials: HS
authors.lastname: Lee
authors.forename: Ji Sang
authors.initials: JS
authors.lastname: Yahng
authors.forename: Hyun Kyu
authors.initials: HK
authors.lastname: Lee
authors.forename: Heh Young
authors.initials: HY
authors.lastname: Moon
authors.forename: Kyoun Joon
authors.initials: KJ
authors.lastname: Kim
authors.forename: Dong Geun
authors.initials: DG
authors.lastname: Lee
authors.forename: Duck Hoon
authors.initials: DH
authors.lastname: Park
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Yu
authors.forename: Suk-Jae
authors.initials: SJ
authors.lastname: Ji