Catalyst-Free Growth of MoS2 Nanorods Synthesized by Dual Pulsed Laser-Assisted Chemical Vapor Deposition and Their Structural, Optical and Electrical Properties

Abstract

Molybdenum disulfide (MoS2) nanorods (NRs) were synthesized from bulk MoS2 using laser-assisted chemical vapor deposition. A q-switched Nd:YAG laser with combined beam wavelengths of 1064┬anm and 532┬anm was used to ablate a solid MoS2 target. A vaporΓCosolid process at a furnace temperature of 1000┬░C was found to support the growth of MoS2 NRs without the need for any metal catalyst. Powder x-ray diffraction analysis (PXRD), field emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, and ultravioletΓCovisible (UVΓCoVis) and photoluminescence (PL) spectroscopy were used to characterize the structural and optical properties of MoS2 NRs. The PXRD revealed the crystallinity and phase purity of the as-synthesized NRs, while electron microscopy showed that MoS2 NRs had lengths in the range of 0.5ΓCo1.2┬a╬╝m and widths between 40┬anm and 160┬anm. UVΓCoVis absorption spectra exhibited broad absorption, and PL measurements showed a sharp emission peak at 379┬anm. Tauc plot calculations determined that the MoS2 NRs showed a direct transition. The electrical conductivity of the NRs was found to be 317.95┬aS/cm. In comparison with the MoS2 nanoparticles, the MoS2 NRs showed higher conductivity due to the in-plane electron transport, which is higher in NRs.