Laser-Driven One- and Two-Dimensional Subwavelength Periodic Patterning of Thin Films Made of a Metal-Organic MoS2 Precursor

ACS Nano. 2022 Jul 26;16(7):10412-10421. doi: 10.1021/acsnano.2c00671. Epub 2022 May 24.

Abstract

Laser-based surface processing is an established way for the maskless generation of surface structures and functionalities on a large variety of materials. Laser-driven periodic surface texturing and structuring of thin films is reported for metallic-, semiconductive-, and polymeric films. Here, we introduce subwavelength surface patterning of metal-organic thin films of [Mo2S4(S2CNnBu2)2], a MoS2 precursor. Accurate control of one- and two-dimensional (1D and 2D) periodic patterns is achieved on silicon wafers with a pulsed 532 nm ns laser. With suitable combinations of laser polarization, laser pulse energy, the thickness of the SiO2 passivation layer, and the MoS2 precursor's thin film thickness, high-quality 1D and 2D self-organized periodic structures are obtained in virtually unlimited areas. The material redistribution related to the pattern formation is thermally driven at low laser energies. Increasing pulse energies beyond a threshold level, in our experiments a factor of 2, fully converts the precursor to MoS2.

Keywords: 2D-LIPSS; laser-induced MoS2 synthesis; laser-induced self-organization; maskless two-dimensional patterning; nanostructured thin film.