Two-dimensional periodic surface nanotexturing of 6H-SiC by ultrashort laser pulses

Year: 2024

Authors: Mastellone M., Bolli E., Valentini V., Bellucci A., Orlando S., Santagata A., Polini R., Lettino A., Sani E., Trucchi DM.

Autors Affiliation: Consiglio Nazl Ric ISM CNR, Ist Struttura Mat, Sede Secondaria Tito Scalo, I-85050 Potenza, Italy; Ist Struttura Mat ISM CNR, DiaTHEMA Lab, Consiglio Nazl Ric, Sede Secondaria Montelibretti, Via Salaria km 29-300, I-00015 Rome, Italy; Univ Roma Tor Vergata, Dipartimento Sci & Tecnol Chim, Via Ric Scientif 1, I-00133 Rome, Italy; Ist Metodol Anal Ambientale CNR IMAA, Consiglio Nazl Ric, I-85050 Potenza, Italy; Ist Nazl Ott CNR INO, Consiglio Nazl Ric, Largo E Fermi 6, I-50125 Florence, Italy.

Abstract: Circularly polarized femtosecond laser pulses have successfully promoted the formation of Two -Dimensional Laser Induced Periodic Surface Structures (2D-LIPSS) exhibiting a sub -wavelength periodicity of 150 +/- 20 nm on semi -insulating 6H-SiC samples. The main objective of this study was to discern the formation of twodimensional LIPSS depending on the single pulse energy and the number of pulses released per unit area. The experimental laser system used in this study generates pulses with a duration of 100 fs, a wavelength of 800 nm, and operates at a repetition rate of 1 kHz. Micro -Raman spectroscopy confirms the presence of the characteristic 6H-SiC peaks across all irradiated samples, indicating that the processing technique does not induce significant compositional variations. Nonetheless, the analysis reveals the induction of compressive stress within the lattice structure. Samples treated across the entire surface were characterized by using optical analysis in order to assess the induced variations in absorptance and emittance due to laser irradiation. The treated samples exhibit solar absorptance values of approximately 75 % and a high spectral selectivity up to 2.0 for temperatures higher than 1000 K. This highlights the potential of fs-laser surface textured 6H-SiC plates as viable selective solar absorbers for energy conversion devices operating at elevated temperatures.

Journal/Review: SURFACES AND INTERFACES

Volume: 46      Pages from: 104006-1  to: 104006-8

KeyWords: Laser texturing; Silicon carbide; LIPSS; Surface functionalization; Cold processing
DOI: 10.1016/j.surfin.2024.104006

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