Thermoelectric Properties of n-Type Molybdenum Disulfide (MoS₂) Thin Film by Using a Simple Measurement Method

In this paper, a micrometre thin film of molybdenum disulfide (MoS₂) is characterized for thermoelectric properties. The sample was prepared through mechanical exfoliation of a molybdenite crystal. The Seebeck coefficient measurement was performed by generating a temperature gradient across the sample and recording the induced electrical voltage, and for this purpose a simple measurement setup was developed. In the measurement, platinum was utilized as reference material in the electrodes. The Seebeck value of MoS₂ was estimated to be approximately -600 µV/K at a temperature difference of 40 °C. The negative sign indicates that the polarity of the material is n-type. For measurement of the thermal conductivity, the sample was sandwiched between the heat source and the heat sink, and a steady-state power of 1.42 W was provided while monitoring the temperature difference across the sample. Based on Fourier's law of conduction, the thermal conductivity of the sample was estimated to be approximately 0.26 Wm^-1 K^-. The electrical resistivity was estimated to be 29 Ω cm. The figure of merit of MoS₂ was estimated to be 1.99 × 10^-4.