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Ablation mechanisms of nanosecond and picosecond laser scribing for metal halide perovskite module interconnection – An experimental and numerical analysis

Schultz, Christof ; Fenske, Markus ; Dagar, Janardan ; Zeiser, Andreas ; Bartelt, Andreas ; Schlatmann, Rutger ; Unger, Eva LU and Stegemann, Bert (2020) In Solar Energy 198. p.410-418
Abstract

Laser-based fabrication of metal-halide perovskite mini-modules has recently been demonstrated using nanosecond (ns) laser pulses. However, it still suffers from high-resistance contacts due to remaining PbI2 residues at the bottom of the absorber-opening P2 scribe line. Therefore, in this study, we investigate the effect of shorter picosecond (ps) laser pulses, and thus lower heat input, on the complete removal of perovskite during P2 laser patterning to achieve low series resistances and thus improved electrical performances. Based on a systematic variation of the incident laser fluence and a comprehensive electrical, morphological and compositional analysis of the scribed area, optimal process windows for successful... (More)

Laser-based fabrication of metal-halide perovskite mini-modules has recently been demonstrated using nanosecond (ns) laser pulses. However, it still suffers from high-resistance contacts due to remaining PbI2 residues at the bottom of the absorber-opening P2 scribe line. Therefore, in this study, we investigate the effect of shorter picosecond (ps) laser pulses, and thus lower heat input, on the complete removal of perovskite during P2 laser patterning to achieve low series resistances and thus improved electrical performances. Based on a systematic variation of the incident laser fluence and a comprehensive electrical, morphological and compositional analysis of the scribed area, optimal process windows for successful laser-based series interconnection are identified and evidenced by current density-voltage curves. The amount of PbI2 debris at the scribe bottom is reduced by using ps instead of ns pulses, resulting in improved j-V performance due to higher fill factor and lower series resistance. A numerical analysis of the laser-induced depth-dependent temperature profile shows that overcritical heating for both pulse durations induces explosive boiling of the excited volume, but only in the case of ns structuring the melting point of the underlying transparent oxide contact layer is exceeded. The corresponding scribed line morphology shows features of thermally-driven direct ablation (i.e., splashes), whereas ps pulses produce scribe lines with steep walls and delaminated areas, indicating a mechanical stress-assisted lift-off ablation. Accordingly, P2 laser patterning with ps pulses is recommended due to favorable morphological (steep edges) as well as composition-related (less PbI2 residues) scribe line properties.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
keywords
Ablation, Laser, Perovskite, Photovoltaic, Series interconnection, Solar module, Thin film
in
Solar Energy
volume
198
pages
9 pages
publisher
Elsevier
external identifiers
  • scopus:85078783065
ISSN
0038-092X
DOI
10.1016/j.solener.2020.01.074
language
English
LU publication?
no
id
2f83550b-1944-4e41-873b-070ea65ade76
date added to LUP
2021-01-22 16:32:32
date last changed
2022-04-26 23:50:51
@article{2f83550b-1944-4e41-873b-070ea65ade76,
  abstract     = {{<p>Laser-based fabrication of metal-halide perovskite mini-modules has recently been demonstrated using nanosecond (ns) laser pulses. However, it still suffers from high-resistance contacts due to remaining PbI<sub>2</sub> residues at the bottom of the absorber-opening P2 scribe line. Therefore, in this study, we investigate the effect of shorter picosecond (ps) laser pulses, and thus lower heat input, on the complete removal of perovskite during P2 laser patterning to achieve low series resistances and thus improved electrical performances. Based on a systematic variation of the incident laser fluence and a comprehensive electrical, morphological and compositional analysis of the scribed area, optimal process windows for successful laser-based series interconnection are identified and evidenced by current density-voltage curves. The amount of PbI<sub>2</sub> debris at the scribe bottom is reduced by using ps instead of ns pulses, resulting in improved j-V performance due to higher fill factor and lower series resistance. A numerical analysis of the laser-induced depth-dependent temperature profile shows that overcritical heating for both pulse durations induces explosive boiling of the excited volume, but only in the case of ns structuring the melting point of the underlying transparent oxide contact layer is exceeded. The corresponding scribed line morphology shows features of thermally-driven direct ablation (i.e., splashes), whereas ps pulses produce scribe lines with steep walls and delaminated areas, indicating a mechanical stress-assisted lift-off ablation. Accordingly, P2 laser patterning with ps pulses is recommended due to favorable morphological (steep edges) as well as composition-related (less PbI<sub>2</sub> residues) scribe line properties.</p>}},
  author       = {{Schultz, Christof and Fenske, Markus and Dagar, Janardan and Zeiser, Andreas and Bartelt, Andreas and Schlatmann, Rutger and Unger, Eva and Stegemann, Bert}},
  issn         = {{0038-092X}},
  keywords     = {{Ablation; Laser; Perovskite; Photovoltaic; Series interconnection; Solar module; Thin film}},
  language     = {{eng}},
  pages        = {{410--418}},
  publisher    = {{Elsevier}},
  series       = {{Solar Energy}},
  title        = {{Ablation mechanisms of nanosecond and picosecond laser scribing for metal halide perovskite module interconnection – An experimental and numerical analysis}},
  url          = {{http://dx.doi.org/10.1016/j.solener.2020.01.074}},
  doi          = {{10.1016/j.solener.2020.01.074}},
  volume       = {{198}},
  year         = {{2020}},
}