Reply to "Comment on 'Metal Semiconductor Field Effect Transistor with MoS2/Conducting NiOx van der Waals Schottky Interface for Intrinsic High Mobility and Photoswitching Speed'"
In a recent article, we reported metal semiconductor fieldeffect transistors (MESFETs) with a few layer MoS2 channel and its intrinsic high mobility, which was supported by Hall effect measurements and photoswitching dynamics. Yang and Liao made a comment on our report. We authors have carefully read the comments and found some misunderstandings which might be from their lack of in depth review on our MESFETs and Hall effect measurements. Following is our response regarding their three main arguments. The first main argument raised by them is regarding electron carrier concentration in our MoS2 channel of the MESFET, which was measured to be 4.03 x 10 cm 2 for N2d (or 2.52 x 10 cm 3 for N3d) Although citing four other reports, Liao et al. claim that N2d of a few layer MoS2 should be 2 orders of magnitude higher than our value even without any gate voltage support, and it may not be acceptable because of two reasons. First of all, previous older papers reported the doping concentration of unintentionally doped thin exfoliated/bulk MoS2 as ~10 cm 3 for N3d (10 10 cm 2 for N2d) Moreover, two among four reports cited by Yang and Liao show that the metal insulator field effect transistor (MISFET) devices were supported by positive gate bias. According to ref 8, where Hall measurement on a few layer MoS2 MISFET channel with a 285 nm thick SiO2/p Si universal back gate was conducted, Hall measurement could not be carried out without positive voltage back gating because good ohmic contact between the electrode and few layer MoS2 is not possible without electron accumulation by back gate support. That is why we used mechanically exfoliated, 16 nm thick MoS2 on the glass substrate for Hall measurements. As a result, we could obtain a maximum carrier concentration of 2.52 x 10 cm 3 for N3d at room temperature and also confirmed that the electron concentration decreases with the measurement temperature decrease. The second argument by Liao et al. is basically the same as their first argument, pointing out that we used 2 orders of magnitude lower N2d for mobility calculation. However, here they add more mistakes for the mobility calculation, equating MISFETs of 0 gate voltage status with our MESFET device.
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