Intense femtosecond photoexcitation of bulk and monolayer MoS2

TL;DR

This study investigates how femtosecond laser pulses cause damage to bulk and monolayer MoS2, analyzing the damage mechanisms, thresholds, and effects of different photon absorption processes.

Contribution

It provides the first detailed comparison of laser-induced damage thresholds and mechanisms in bulk and monolayer MoS2 under femtosecond irradiation.

Findings

Damage thresholds for monolayer and bulk MoS2 were quantified.

Laser-induced bond breaking and atom removal were identified as damage mechanisms.

The role of two-photon versus one-photon absorption effects was discussed.

Abstract

The effect of femtosecond laser irradiation on bulk and single-layer MoS2 on silicon oxide is studied. Optical, Field Emission Scanning Electron Microscopy (FESEM) and Raman microscopies were used to quantify the damage. The intensity of A1g and E2g1 vibrational modes was recorded as a function of the number of irradiation pulses. The observed behavior was attributed to laser-induced bond breaking and subsequent atoms removal due to electronic excitations. The single-pulse optical damage threshold was determined for the monolayer and bulk under 800nm and 1030nm pulsed laser irradiation and the role of two-photon versus one photon absorption effects is discussed.