Field-effect transistors and intrinsic mobility in ultra-thin MoSe2 layers

Abstract

We report the fabrication of back-gated field-effect transistors (FETs) using ultra-thin, mechanically exfoliated MoSe 2 flakes. The MoSe 2 FETs are n-type and possess a high gate modulation, with On/Off ratios larger than 10 6 . The devices show asymmetric characteristics upon swapping the source and drain, a finding explained by the presence of Schottky barriers at the metal contact/MoSe 2 interface. Using fourpoint, back-gated devices we measure the intrinsic conductivity and mobility of MoSe 2 as a function of gate bias, and temperature. Samples with a room temperature mobility of ~50 cm 2 /V·s show a strong temperature dependence, suggesting phonons are a dominant scattering mechanism.

Repairing atomic vacancies in single-layer MoSe2 field-effect transistor and its defect dynamics

“…We find that the unprocessed sample presents the mobility of 0.1 cm 2 /Vs while the processed sample holds the mobility of 30 ± 6 cm 2 /Vs (consider the contact resistance). 31,[38][39][40][41] It shows great mobility improvement by 2-3 orders of magnitude after the EDTA processing. It it noted that the device is turned on when back gate voltage is positive, which is the signature of the electron dominance and the mobility data obtained above are for electrons.…”

“…[23][24][25][26][27][28] The defects also cause more severe influence on the device performance since the quantum paths are greatly suppressed in the 2D electronic transport. 23,24,29 For the SLM FET, such defects lead to various carrier mobilities, 19,24,[30][31][32][33] and defect repairing is the focus of concern during these years. 17,28,34,35 Here we report that a simple drop of chemical solution may repair the defect-rich SLM FET, by which the carrier mobility increases from 0.1 to around 30 cm 2 /Vs.…”

Monolayer MoSe2 Grown by Chemical Vapor Deposition for Fast Photodetection

“…The output characteristics for the MoSe2 devices are also shown in Figure S2. is an n-type semiconductor, 44 we clearly observe an ambipolar transport behavior instead since the electric double layer exhibits a higher gating efficiency. Table 1.…”

Ultrathin MoO2 nanosheets with good thermal stability and high conductivity

“…These conductivities are just above the results of MoO 2 nanorods, and much higher than the conductivities of other 2D compounds such as transition metal dichalcogenides, black phosphorus, and SnO. 2,[34][35][36][37] The exceptionally high conductivity of individual MoO 2 nanosheet is ascribed to the unique crystal structure. To the best of our knowledge, the m-MoO 2 crystal has a rutile-type structure, which is built up by MoO 6 octahedral units (see inset of Fig.…”