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

Abstract

Abstract In this work, MoS 2 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 MoS 2 NPs was studied. X-ray diffraction (XRD) studies reveal that the synthesized MoS 2 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 MoS 2 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 MoS 2 shows formation (Mo-S) bond stretching mode. The current-voltage characteristic of n-MoS 2 /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-MoS 2 /p-Si photodetector under illumination was as well performed.