Environmental Effects on Hysteresis of Transfer Characteristics in Molybdenum Disulfide Field-Effect Transistors

Abstract

Molybdenum disulfide (MoS2) has recently received much attention for nanoscale electronic and photonic applications. To explore the intrinsic properties and enhance the performance of MoS2-based field-effect transistors, thorough understanding of extrinsic effects such as environmental gas and contact resistance of the electrodes is required. Here, we report the effects of environmental gases on the transport properties of back-gated multilayered MoS2 field-effect transistors. Comparisons between different gases (oxygen, nitrogen, and air and nitrogen with varying relative humidities) revealed that water molecules acting as charge-trapping centers are the main cause of hysteresis in the transfer characteristics. While the hysteresis persisted even after pumping out the environmental gas for longer than 10 h at room temperature, it disappeared when the device was cooled to 240 K, suggesting a considerable increase in the time constant of the charge trapping/detrapping at these modestly low temperatures. The suppression of the hysteresis or instability in the easily attainable temperature range without surface passivation is highly advantageous for the device application of this system. The humidity dependence of the threshold voltages in the transfer curves indicates that the water molecules dominantly act as hole-trapping centers. A strong dependence of the on-state current on oxygen pressure was also observed.

Integrated Circuits Comprising Patterned Functional Liquids

“…This number was determined by boundary conditions of our setup, and should not suggest any limit to the possible integration level. [26] This behavior of the drain currents is consistent with a similar behavior reported for water-gated MoS 2 FETs [27,28] and is to be expected as the H 2 O molecules in direct contact with the drain-source channel act as charge scattering and trapping centers. Figure 4c shows the roomtemperature output characteristic I D (V DS ) of such an integrated FET.…”

Robustness testing and scalability of phosphate regulated promoters useful for two-stage autoinduction inE. coli

“…24 By analogy, in electrical engineering, electronic components (parts) always have design specifications which include boundary conditions for desired operation, whether these are key inputs (voltage, current) or environmental specifications including temperature, humidity, etc. 25,26 Promoter, and part, robustness enables faster translation of performance from one context to another, such as from one media to another or across production scales. The lack of scalability of the mipA , phoH and ydfH promoters from minimal media in microfermentations to bioreactors, may indeed be due to protocol differences between the two experiments, including media differences.…”

Synthesis and Characterization of Zirconium Disulfide Single Crystals and Thin‐Film Transistors Based on Multilayer Zirconium Disulfide Flakes

“…The significant asymmetry for V g =50 V is attributed to n‐channel characteristics, which is also indicated by the transfer characteristics ( I ds – V g curve), as shown in Figure b (linear scale) and Figure c (semilogarithmic scale). The transfer characteristics are associated with large hysteresis, which implies that significant charge trapping/detrapping is involved during the sweep of V g . The trap sites may be at the interface of ZrS 2 or intrinsic to the ZrS 2 flake.…”

“…For application to FET devices, it is desirable to suppress the hysteresis in the transfer curves, which is closely associated with instability, that is, the time‐dependent I ds as shown in Figure d. Possible methods for suppressing hysteresis include evacuating to vacuum, cooling, and covering the channel with high dielectric materials ,,. These methods effectively eliminate the surface adsorbates that are responsible for the hysteresis.…”