Chemically exfoliated large-area two-dimensional flakes of molybdenum disulfide for device applications

Abstract

A solution-based exfoliation method for obtaining large-area two-dimensional flakes of molybdenum disulfide, followed by the fabrication of electrical devices is presented in this manuscript. The exfoliation method is based on the use of an aprotic solvent, namely, acetonitrile under mild sonication steps. In order to fabricate devices, a dielectrophoresis technique is used for transferring MoS2 flakes site-specifically on to the electrode pairs pre-written on the glass chips. The devices fabricated thus can be operated as chemical sensor in liquids while investigations under photo illumination indicate that such devices can also efficiently function as photodetectors

Graphite oxide multilayers for device fabrication: Enzyme‐based electrical sensing of glucose

“…ϵ 0 is permittivity of vacuum, ϵ r is the relative permittivity of the buffer solution, A is the surface area and l d is Debye length, c edl is the EDLC, and V ds is the drain–source bias. The transconductance values are calculated by taking a first derivative of the field‐effect transport curves (current vs. gate voltage) . Here the values are taken for the device as shown in Fig.…”

“…A new class of nanomaterials, namely two‐dimensional materials, has instigated important developments in the field of electronic sensors in recent years . A candidate material is the two‐dimensional form of sp 2 hybridized carbon atoms, i.e., graphene .…”

Chemical and Electronic Repair Mechanism of Defects in MoS2 Monolayers

“…A free-standing, perfect 2D MoS 2 monolayer possesses a direct band gap of 1.88 eV at the Kpoint in the Brillouin zone. 4,5 Most commonly used production methods for MoS 2 monolayers are chemical vapor deposition (CVD) and mechanical exfoliation of the layered bulk material, [6][7][8] as well as sputter growth atomic layer deposition 9 (ALD) of the precursor MoO 3 and subsequent conversion to the disulfide under reducing conditions and at high temperatures. 10,11 A direct ALD process using H 2 S and MoCl 5 12 or Mo(CO) 6 13 is another possibility to obtain MoS 2 monolayers.…”

MoS2 Nanosheet–Pd Nanoparticle Composite for Highly Sensitive Room Temperature Detection of Hydrogen

“…A lithium intercalation method can be used to exfoliate bulk MoS 2 crystals to produce single layer MoS 2 nanosheets. However, this method requires a long lithiation process (3 days) and results in MoS 2 nanosheets with traces of lithium particles, which degrades the MoS 2 semiconducting properties . On the other hand, solvent exfoliation method can provide high yield and fast production of a few layer MoS 2 nanosheets, in which exfoliation takes place by ultrasonication of bulk MoS 2 in suitable solvents such as N ‐methyl‐pyrrolidone (NMP) or isopropanol whose surface tension is in the range of 30–40 mJ m −2 , which facilitates the exfoliation process …”