Micro- and Nanostructuring with Lasers

Energy dispersive X-ray spectroscopy image of a copper-indium-gallium-diselenid (CIGS) solar cell, with molybdenum back-contact and ITO front-contact, structured by picosecond laser irradiation.

This group works on the development of laser induced processes for the modification and structuring of surfaces and thin films, for use in micro- and nanotechnology. Apart from looking into the physical properties of laser deposition, the process itself is further optimized (low structural depth, precise determination of the ablation depth, selective layer ablation, lowest possible structural damage of materials and components).
This modification and structuring is carried out by the use of ultra-short laser pulses which excite non‑thermal laser photon-material interactions. 
This method represents a novel approach to the fabrication and processing of materials.

Apart from laser ablation, innovative laser induced processes for the creation of micro- and nanostructures as well as material modifications are increasingly used.

Selected Publications

  • X. Wang, M. Ehrhardt, P. Lorenz, C. Scheit, S. Ragnow, X.W. Ni, K. Zimmer, In-process measuring of the electrical shunt resistance of laser-scribed thin-film stacks by nested circular scribes, Rev. Sci. Instr. 84 (2013), 104704.
  • M. Ehrhardt, P. Lorenz, F. Frost, K. Zimmer, Fabrication of sub-microstructures in solid copper surfaces by inverse laser microembossing, Applied Physics A: Materials Science & Processing 111 (2013), 517-523.
  • M. Ehrhardt, A. Wehrmann, P. Lorenz, K. Zimmer, Patterning of CIGS thin films induced by rear-side laser ablation of polyimide carrier foil, Applied Physics A 113 (2013), 309-313

  • A. Wehrmann, S. Puttnins, L. Hartmann, M. Ehrhardt, P. Lorenz, K. Zimmer, Analysis of laser scribes at CIGS thin-film solar cells by localized electrical and optical measurements, Optics & Laser Technology 44 (2012), 1753-1757.
  • K. Zimmer, M. Ehrhardt, R. Böhme, Laser-Induced Backside Wet Etching: Processes, Results, and Applications, in: G. Yang (Ed.) Laser Ablation in Liquids, Pan Stanford Publishing Singapore (2012), 1013 - 1132.