Combined electrical transport and capacitance spectroscopy of a MoS2-LiNbO3 field effect transistor

W. Michailow, F. J. R. Schülein, B. Möller, E. Preciado, A. E. Nguyen, G. v. Son, J. Mann, A. L. Hörner, A. Wixforth, L. Bartels, H. J. Krenner

Applied Physics Letters 110, 023505 (2017) DOI: APL

We have measured both the current-voltage (ISD-VGS) and capacitance-voltage (C-VGS) characteristics of a MoS2LiNbO3 field effect transistor. From the measured capacitance we calculate the electron surface density and show that its gate voltage dependence follows the theoretical prediction resulting from the two-dimensional free electron model. This model allows us to fit the measured ISD-VGS characteristics over the entire range of VGS. Combining this experimental result with the measured current-voltage characteristics, we determine the field effect mobility as a function of gate voltage. We show that for our device this improved combined approach yields significantly smaller values (more than a factor of 4) of the electron mobility than the conventional analysis of the current-voltage characteristics only.