We explore the electrical characteristics of TiS 3 nanowire field-effect transistor (FETs), over the wide temperature range from 3 to 350 K. These nanomaterials have a quasi-one-dimensional (1D) crystal structure and exhibit a gate-controlled metal−insulator transition (MIT) in their transfer curves. Their room-temperature mobility is ∼20−30 cm 2 /(V s), 2 orders of magnitude smaller than predicted previously, a result that we explain quantitatively in terms of the influence of polar-optical phonon scattering in these materials. In the insulating state (<∼220 K), the transfer curves exhibit unusual mesoscopic fluctuations and a current suppression near zero bias that is common to charge-density wave (CDW) systems. The fluctuations have a nonmonotonic temperature dependence and wash out at a temperature close to that of the bulk MIT, suggesting they may be a feature of quantum interference in the CDW state. Overall, our results demonstrate that quasi-1D TiS 3 nanostructures represent a viable candidate for FET realization and that their functionality is influenced by complex phenomena.

We study temperature dependent (200 – 400 K) dielectric current leakage in high-quality, epitaxial chromia films, synthesized on various conductive substrates (Pd, Pt and V2O3). We find that trap-assisted space-charge limited conduction is the dominant source of electrical leakage in the films, and that the density and distribution of charge traps within them is strongly dependent upon the choice of the underlying substrate. Pd-based chromia is found to exhibit leakage consistent with the presence of deep, discrete traps, a characteristic that is related to the known properties of twinning defects in the material. The Pt- and V2O3-based films, in contrast, show behavior typical of insulators with shallow, exponentially-distributed traps. The highest resistivity is obtained for chromia fabricated on V2O3 substrates, consistent with a lower total trap density in these films. Our studies suggest that chromia thin films formed on V2O3 substrates are a promising candidate for next-generation spintronics.

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2D semiconductors such as monolayer molybdenum disulfide (MoS2) are promising material candidates for next‐generation nanoelectronics. However, there are fundamental challenges related to their metal–semiconductor (MS) contacts, which limit the performance potential for practical device applications. In this work, 2D monolayer hexagonal boron nitride (h‐BN) is exploited as an ultrathin decorating layer to form a metal–insulator–semiconductor (MIS) contact, and an innovative device architecture is designed as a platform to reveal a novel diode‐like selective enhancement of the carrier transport through the MIS contact. The contact resistance is significantly reduced when the electrons are transported from the semiconductor to the metal, but is barely affected when the electrons are transported oppositely. A concept of carrier collection barrier is proposed to interpret this intriguing phenomenon as well as a negative Schottky barrier height obtained from temperature‐dependent measurements, and the critical role of the collection barrier at the drain end is shown for the overall transistor performance.

We fabricated graphene field-effect transistors (GFETs) with hybrid organic/inorganic gate dielectrics, in which parylene C is used as the organic component. The HOMO−LUMO gap of parylene is large enough to provide effective gate insulation, yet significantly smaller than that of the inorganic component (SiO 2 ) of the dielectric. This allows this polymeric material to serve as an effective "floating node" that may be programmed by applying large voltage pulses to the GFET drain. We identify the role of two types of trapping in these devices: the first is mediated by short-lived interfacial states at the graphene−parylene interface, while the second, which is responsible for the nonvolatile memory function, involves hot-carrier injection into long-lived trap states deep in the parylene layer. Retention measurements demonstrate that charge injected into the parylene interior may be retained over long decay times (months), thereby confirming the potential of graphene-on-parylene for nonvolatile memory implementations.