Investigating the effect of defect states and to enhance the electrical conductivity of p-type Vanadium-doped MoS2 for wearable thermoelectric application

Molybdenum disulfide (MoS2) and vanadium (V) doped MoS2 nanosheets grown on carbon fabric had been synthesized as a wearable thermoelectric (WTEGs) leg. The structural analysis confirmed the formation of MoS2 nanosheets on carbon fabric. Raman analysis showed the decrease in structural defects, thus leading to the strong interaction between the MoS2 and carbon fabric, which endows the higher charge mobility. Pristine MoS2/CC and V-doped MoS2/CC exhibited flower-like morphology and the growth mechanism of has been proposed. The presence of Mo–O–C bonds shows that the carbon cloth surfaces have several OH active sites, thus they can also serve as excellent nucleation sites for MoS2. This interfacial interaction enhances the electron transport rate and structural stability. The MV2 sample demonstrated an increase in electrical conductivity of 2639.26 S/m at 303 K and 2784.55 S/m at 373 K, which was higher than the MV0 and MV4 samples. The enhancement in electrical conductivity was due extra charge carrier released by V3+ ions. Further, a thermopile was built utilizing V doped MoS2 nanosheets grown on carbon fabric (i.e., an MV4 sample with a high Seebeck coefficient) as the p-type material and Ag-fabric as the n-type material. This WTEGs device showed an output voltage in the range of 17.96–37.24 mV and output power in the range of 0.18–0.48 pW with a ΔT = 3–10 K, respectively.