Novel synthesis of MoS2 nanoparticles via pulsed laser ablation in liquid for high-performance photodetection applications

In this work, MoS2 nanoparticles (NPs) are synthesized by laser ablation of molybdenum in thiourea. The effect of adding of sodium dodecyl benzene sulfonate (SDS) surfactant to thiourea on the properties of MoS2 NPs was studied. X-ray diffraction (XRD) studies reveal that the synthesized MoS2 NPs were crystalline with hexagonal structures. Field-emission scanning electron microscope (FESEM) investigations confirm the synthesized MoS2 NPs have spherical and hexagonal morphologies. The energy band-gap of MoS2 prepared in thiourea solution was about 1.2 eV and after addition of SDS is about 1.5 eV. The chemical bonds between Mo-S at peaks at 766, 894 and 1457 cm− 1 were identified by FTIR analysis. The Raman spectra of MoS2 shows formation (Mo-S) bond stretching mode. The current-voltage characteristic of n-MoS2/p-Si heterojunction prepared in thiourea and thiourea + SDS solutions were inspected during dark and illumination settings. The results reveal the responsivity of the fabricated devices increased from 0.9 to 1.17 A/W at 650 nm upon the addition of SDS surfactant to thiourea. The detectivity and quantum efficiency of the photodetector increases significantly after adding SDS surfactant. Energy band lineup of n-MoS2/p-Si photodetector under illumination was as well performed.