Metal–insulator crossover in multilayered MoS<sub>2</sub>

Park, Min Ji; Yi, Sum Gyun; Kim, Joo Hyung; Yoo, Kyung Hwa

doi:10.1039/c5nr05223h

Cited by 18 publications

(14 citation statements)

References 40 publications

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“…4(b) shows the 2P conductance of the 2H region as a function of the back-gate voltage, V bg , at 300 K (red trace) and 4 K (blue trace). The device exhibits clear n-type behaviour with a field effect mobility of 16.4 cm 2 /V-s at 300 K and 84 cm 2 /V-s at 4 K, which are in the range of typically observed mobility values for an uncapped, back-gated 2H MoS 2 FET 44 . In contrast, the I-V characteristics of the plasma treated region, 1T, shown in Fig.…”

Section: Resultssupporting

confidence: 53%

Stable and scalable 1T MoS2 with low temperature-coefficient of resistance

Sharma

Surendran

Varghese

et al. 2018

Sci Rep

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Monolithic realization of metallic 1T and semiconducting 2H phases makes MoS2 a potential candidate for future microelectronic circuits. A method for engineering a stable 1T phase from the 2H phase in a scalable manner and an in-depth electrical characterization of the 1T phase is wanting at large. Here we demonstrate a controllable and scalable 2H to 1T phase engineering technique for MoS2 using microwave plasma. Our method allows lithographically defining 1T regions on a 2H sample. The 1T samples show excellent temporal and thermal stability making it suitable for standard device fabrication techniques. We conduct both two-probe and four-probe electrical transport measurements on devices with back-gated field effect transistor geometry in a temperature range of 4 K to 300 K. The 1T samples exhibit Ohmic current-voltage characteristics in all temperature ranges without any dependence to the gate voltage, a signature of a metallic state. The sheet resistance of our 1T MoS2 sample is considerably lower and the carrier concentration is a few orders of magnitude higher than that of the 2H samples. In addition, our samples show negligible temperature dependence of resistance from 4 K to 300 K ruling out any hoping mediated or activated electrical transport.

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Section: Resultssupporting

confidence: 53%

Stable and scalable 1T MoS2 with low temperature-coefficient of resistance

Sharma

Surendran

Varghese

et al. 2018

Sci Rep

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“…S4 †), which further confirmed the superiority of the bottom graphene contact. 40 Fig. 5c shows the double sweep of the transfer characteristics at both high and low temperatures.…”

Section: Characterization Of a Device With A Bottom Graphene Contactmentioning

confidence: 99%

Self-screened high performance multi-layer MoS₂transistor formed by using a bottom graphene electrode

Liu

Ahmed

et al. 2015

Nanoscale

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We investigated the carrier transport in multi-layer MoS2 with consideration of the contact resistance (R(c)) and interlayer resistance (R(int)). A bottom graphene contact was suggested to overcome the degradation of I(d) modulation in a back gated multi-layer MoS2 field effect transistor (FET) due to the accumulated R(int) and increased R(c) with increasing thickness. As a result, non-degraded drain current (I(d)) modulation with increasing flake thickness was achieved due to the non-cumulative R(int). Benefiting from the low R(c) induced by the negligible Schottky barrier at the graphene/MoS2 interface, the intrinsic carrier transport properties immune to R(c) were investigated in the multi-layer MoS2 FET. ∼2 times the enhanced carrier mobility was attained from the self-screened channel in the bottom graphene contacted device, compared to those with top metal contacts.

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“…Since the first experiments on graphene [34] the charge transport mechanisms in isolated flakes of 2D materials have been extensively investigated, ranging all the way from semiconductors such as MoS 2 [35][36][37][38][39][40][41][42], to semimetals such as graphene [43][44][45][46][47][48][49], to metals such as MXenes [50][51][52][53][54][55][56][57]. However, the structure of inkjet-printed films consist of a large number of highly-crystalline flakes assembled together in a three-dimensional network [1], and is more complex than that of isolated flakes.…”

Section: Introductionmentioning

confidence: 99%

Charge transport mechanisms in inkjet-printed thin-film transistors based on two-dimensional materials

et al. 2021

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Printed electronics has emerged as a pathway for large scale, flexible, and wearable devices enabled by graphene and two-dimensional (2D) materials. Solution processing of graphite and layered materials demonstrated mass production of inks allowing techniques such as inkjet printing to be used for device fabrication. However, the complexity of the ink formulations and the polycrystalline nature of the thin films, together with the metal, semimetal, and semiconducting behaviour of different 2D materials, have impeded the investigation of charge transport in inkjet printed 2D material devices. Here we unveil the charge transport mechanisms of surfactant-and solvent-free inkjet-printed thin-film devices of representative few-layer graphene (semi-metal), molybdenum disulfide (MoS2, semiconductor) and titanium carbide MXene (Ti3C2, metal) by investigating the temperature (T ), gate and magnetic field dependencies of their electrical conductivity. We find that charge transport in printed few-layer MXene and MoS2 devices is dominated by the intrinsic transport mechanism of the constituent flakes: MXene devices exhibit a weakly-localized 2D metallic behavior at any T , whereas MoS2 devices behave as insulators with a crossover from 3D-Mott variable-range hopping at low T to nearest-neighbor hopping around at ∼ 200 K. The charge transport in printed few-layer graphene devices is dominated by the transport mechanism between different flakes, which exhibit 3D-Mott variable range hopping conduction at any T . These findings reveal and finally establish the fundamental mechanisms responsible for charge transport in inkjet-printed devices with 2D materials, paving the way for a reliable design of high performance printed electronics.

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Metal–insulator crossover in multilayered MoS₂

Cited by 18 publications

References 40 publications

Stable and scalable 1T MoS2 with low temperature-coefficient of resistance

Stable and scalable 1T MoS2 with low temperature-coefficient of resistance

Self-screened high performance multi-layer MoS₂transistor formed by using a bottom graphene electrode

Charge transport mechanisms in inkjet-printed thin-film transistors based on two-dimensional materials

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Metal–insulator crossover in multilayered MoS2

Cited by 18 publications

References 40 publications

Stable and scalable 1T MoS2 with low temperature-coefficient of resistance

Stable and scalable 1T MoS2 with low temperature-coefficient of resistance

Self-screened high performance multi-layer MoS2transistor formed by using a bottom graphene electrode

Charge transport mechanisms in inkjet-printed thin-film transistors based on two-dimensional materials

Contact Info

Product

Resources

About

Metal–insulator crossover in multilayered MoS₂

Self-screened high performance multi-layer MoS₂transistor formed by using a bottom graphene electrode