LM-PS-8
Femtosecond and picosecond laser-induced damage thresholds of semiconductors in air and water
M. Stehlik1,2, C. Liberatore1,1. Mirza1, N.M. Bulgakova1,3, A.V. Bulgakov1,3
1HiLASE Centre, Institute of Physics of the Czech Academy of Sciences, Dolni Brezany, Czech
Republic
2Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Praha, Czech Republic
3Kuteteladze Institute of Thermophysics, Siberian Branch of RAS, Novosibirsk, Russian Federation
Nanoparticle synthesis and micro-/nanostructure generation can be achieved by an efficent and versatile method of pulsed laser ablation in liquids (PLAL). PLAL is based on a simple experimental arrangement but its theoretical description is difficult and still involves many unanswered questions. Theoretical models of the laser ablation process work usually with a damage threshold (DT) parameter which is precisely defined and can be accurately measured. Surprisingly, published experimental results on the DTs in liquids are contradictory when compared to results of the DTs in air. Explanations of the influence of the ambient environment are based on different physical mechanisms such as light scattering [1], heat transfer to liquid, reflectivity [2] or vapor pressure. Here, we provide results of a systematical study of the DTs of semiconductors (Si, Ge) irradiated by near infrared (1030 nm) laser pulses in water. The experiments were done with the targets irradiated by fs (260 fs) and ps (7 ps) laser pulses in singleshot and multi-shot regimes. The DT results in water are compared to ones in air which were obtained under the same irradiation multi-shot regimes. The discussion of DT results takes into account the influence of pulse duration, accumulation effects in the multi-shot irradiation regimes, and nonlinear effects during ultrashort laser pulse propagation in water.
References
[1] S. V. Starinskiy, Y. G. Shukhov, A. V. Bulgakov, Laser-induced damage thresholds of gold, silver and their alloys in air and water, Appl. Surf. Sci. 396, 1765 (2017).
[2] H. Liu, F. Chen, X. Wang, Q. Yang, H. Bian, J. Si, X. Hou, Influence of liquid environments on femtosecond laser ablation of silicon, Thin Solid Films. 518, 5188 (2010).