Urban, F.; Martucciello, N.; Peters, L.; McEvoy, N.; Di Bartolomeo, A. Environmental Effects on the Electrical Characteristics of Back-Gated WSe2 Field-Effect Transistors. Nanomaterials2018, 8, 901.
Urban, F.; Martucciello, N.; Peters, L.; McEvoy, N.; Di Bartolomeo, A. Environmental Effects on the Electrical Characteristics of Back-Gated WSe2 Field-Effect Transistors. Nanomaterials 2018, 8, 901.
We study the effect of polymer coating, pressure, temperature and light on the electrical characteristics of monolayer WSe2 back-gated transistors with quasi-ohmic Ni/Au contacts. We prove that the removal of a layer of poly(methyl methacrylate) or a decrease of the pressure change the device conductivity from p to n-type. We demonstrate a gate-tunable Schottky barrier at the contacts and measure a barrier height of ~70 meV in flat-band condition. We report and discuss a temperature-driven change in the mobility and the subthreshold slope which we use to estimate the trap density at the WSe2/SiO2 interface. We study the spectral photoresponse of the device, that can be used as a photodetector with a responsivity of ~0.5 AW-1 at 700 nm wavelength and 0.37 mW/cm2 optical power.
2D materials, field effect transistors, PMMA, tungsten diselenide
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