Tuning Structural, Optical, and Electrical Transport Properties of Exfoliated MoS₂ Nanosheets Functionalized with Nickel Nanoparticles: Implications for Charge Transport Engineering in Functional Nanodevices

High Resolution Image Download MS PowerPoint Slide In this study, we present a hydrothermal approach for functionalizing few-layer MoS 2 with nickel nanoparticles (NiNPs). The impact of different NiNP loadings (0.025, 0.05, and 0.1 g) on the structural, optical, and electrical transport properties of MoS 2 was systematically investigated. Structural and morphological changes induced by NiNPs were analyzed via X-ray diffraction (XRD), Raman spectroscopy, and electron microscopy. X-ray photoelectron spectroscopy (XPS) revealed changes in the oxidation states of Mo, S, and Ni, indicating strong interfacial interactions. XRD patterns showed a reduction in layer number and evidence of NiNP intercalation, while elemental mapping revealed NiNP agglomeration at higher concentrations. Raman and XPS data confirmed a p-type doping effect caused by electron transfer from MoS 2 to NiNPs. Photoluminescence and UV–vis absorption analyses indicated modulation of excitonic species and bandgap narrowing upon functionalization. Electrical characterization demonstrated that ohmic transport dominated in pristine MoS 2 and highly doped samples, whereas a space-charge-limited current (SCLC) mechanism prevailed at lower and intermediate NiNP concentrations due to defect-induced trap states. These findings demonstrate that NiNP functionalization enables precise tuning of MoS 2 properties, making it a promising candidate for applications in field-effect transistors, photodetectors, solar cells, and chemical or gas sensors that require tailored charge transport, enhanced surface activity, and tunable optical bandgap.