Intense femtosecond photoexcitation of bulk and monolayer MoS2

The effect of femtosecond laser irradiation on bulk and single-layer MoS2 on silicon oxide is studied. Optical, field emission scanning electron microscopy and Raman microscopy were used to quantify the damage. The intensity of A(1g) and E-2g(1) 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 800 nm and 1030 nm pulsed laser irradiation, and the role of two-photon versus one photon absorption effects is discussed. (C) 2014 AIP Publishing LLC.