Gate Voltage Tunable Temperature Coefficient of Resistance of WSe₂ for Thermal Sensing Applications

Two-dimensional (2-D) materials have layered structures with unique properties. One of the properties of interest is the temperature coefficient of resistance (TCR) which should be large for fast thermal sensors. The TCR is the calculation of the relative change in resistance per degree of temperature change. Taking a step further, tunable TCR is a concept that involves the control of TCR by the gate voltage. Here, we have shown that in a field effect transistor (FET) device, the 2-D semiconductor material tungsten diselenide (WSe $_{{2}}{)}$ has a TCR, which can be controlled by varying the applied gate voltage. We also compared it with molybdenum disulfide (MoS $_{{2}}{)}$ and found that the WSe2 TCR is approximately six times that of MoS2 and 19 times that of metallic thin films. Also, WSe2 TCR could be controlled to 300% of its value within 10 V of applied gate voltage. Specific high values of TCR can be tuned using the gate voltage as WSe2 TCR can be selected to −8.7% $\text{K}^{-{1}}$ . This has applications in bolometers, thermal sensors, and accelerometers.