Electrical and optoelectronic anisotropy and surface electron accumulation in ReS nanostructures.

Two interesting electronic transport properties including in-plane anisotropy and nonhomogeneous carrier distribution were observed in ReS nanoflakes. The electrical conductivity defined by the current parallel to the -axis (‖) is 32 times higher than that perpendicular to the -axis (⊥). Similar anisotropy was also observed in optoelectronic properties in which the ratio of responsivity ‖ to ⊥ reaches 20.

Photoconduction Properties in Tungsten Disulfide Nanostructures.

We reported the photoconduction properties of tungsten disulfide (WS) nanoflakes obtained by the mechanical exfoliation method. The photocurrent measurements were carried out using a 532 nm laser source with different illumination powers. The results reveal a linear dependence of photocurrent on the excitation power, and the photoresponsivity shows an independent behavior at higher light intensities (400-4000 Wm).

Molybdenum Disulfide Nanoribbons with Enhanced Edge Nonlinear Response and Photoresponsivity.

MoS nanoribbons have attracted increased interest due to their properties, which can be tailored by tuning their dimensions. Herein, the growth of MoS nanoribbons and triangular crystals formed by the reaction between films of MoOx (2 View Article and Find Full Text PDF

A Bi-Anti-Ambipolar Field Effect Transistor.

Multistate logic is recognized as a promising approach to increase the device density of microelectronics, but current approaches are offset by limited performance and large circuit complexity. We here demonstrate a route toward increased integration density that is enabled by a mechanically tunable device concept. Bi-anti-ambipolar transistors (bi-AATs) exhibit two distinct peaks in their transconductance and can be realized by a single 2D-material heterojunction-based solid-state device.

Unprecedented random lasing in 2D organolead halide single-crystalline perovskite microrods.

Three-dimensional organic-inorganic hybrid halide perovskites have been demonstrated as great materials for applications in optoelectronics and photonics. However, their inherent instabilities in the presence of moisture, light, and heat may hinder their commercialization. Alternatively, emerging two-dimensional (2D) organic-inorganic hybrid perovskites have recently attracted increasing attention owing to their great environmental stability and inherent natural quantum-well structure.

Modulating Charge Separation with Hexagonal Boron Nitride Mediation in Vertical Van der Waals Heterostructures.

Tuning the optical and electrical properties by stacking different layers of two-dimensional (2D) materials enables us to create unusual physical phenomena. Here, we demonstrate an alternative approach to enhance charge separation and alter physical properties in van der Waals heterojunctions with type-II band alignment by using thin dielectric spacers. To illustrate our working principle, we implement a hexagonal boron nitride (h-BN) sieve layer in between an InSe/GeS heterojunction.

Sn-Doping Enhanced Ultrahigh Mobility InSnSe Phototransistor.

Two-dimensional ternary materials are attracting widespread interest because of the additional degree of freedom available to tailor the material property for a specific application. An InSnSe phototransistor possessing tunable ultrahigh mobility by Sn-doping engineering is demonstrated in this study. A striking feature of InSnSe flakes is the reduction in the oxide phase compared to undoped InSe, which is validated by spectroscopic analyses.

Ultra-high performance flexible piezopotential gated InSnSe phototransistor.

Flexible optoelectronic devices facilitated by the piezotronic effect have important applications in the near future in many different fields ranging from solid-state lighting to biomedicine. Two-dimensional materials possessing extraordinary mechanical strength and semiconducting properties are essential for realizing nanopiezotronics and piezo-phototronics. Here, we report the first demonstration of piezo-phototronic properties in InSnSe flexible devices by applying systematic mechanical strain under photoexcitation.

Lipid-Modified Graphene-Transistor Biosensor for Monitoring Amyloid-β Aggregation.

A graphene field-effect transistor (G-FET) with the spacious planar graphene surface can provide a large-area interface with cell membranes to serve as a platform for the study of cell membrane-related protein interactions. In this study, a G-FET device paved with a supported lipid bilayer (referred to as SLB/G-FET) was first used to monitor the catalytic hydrolysis of the SLB by phospholipase D. With excellent detection sensitivity, this G-FET was also modified with a ganglioside G-enriched SLB (G-SLB/G-FET) to detect cholera toxin B.

One-Step Synthesis of Antioxidative Graphene-Wrapped Copper Nanoparticles on Flexible Substrates for Electronic and Electrocatalytic Applications.

In this study, we report a novel, one-step synthesis method to fabricate multilayer graphene (MLG)-wrapped copper nanoparticles (CuNPs) directly on various substrates (e.g., polyimide film (PI), carbon cloth (CC), or Si wafer (Si)).

Detection of K Efflux from Stimulated Cortical Neurons by an Aptamer-Modified Silicon Nanowire Field-Effect Transistor.

The concentration gradient of K across the cell membrane of a neuron determines its resting potential and cell excitability. During neurotransmission, the efflux of K from the cell via various channels will not only decrease the intracellular K content but also elevate the extracellular K concentration. However, it is not clear to what extent this change could be.

Targeted and efficient activation of channelrhodopsins expressed in living cells via specifically-bound upconversion nanoparticles.

Optogenetics is an innovative technology now widely adopted by researchers in different fields of biological sciences. However, most light-sensitive proteins adopted in optogenetics are excited by ultraviolet or visible light which has a weak tissue penetration capability. Upconversion nanoparticles (UCNPs), which absorb near-infrared (NIR) light to emit shorter wavelength light, can help address this issue.

High photosensitivity and broad spectral response of multi-layered germanium sulfide transistors.

In this paper, we report the optoelectronic properties of multi-layered GeS nanosheet (∼28 nm thick)-based field-effect transistors (called GeS-FETs). The multi-layered GeS-FETs exhibit remarkably high photoresponsivity of Rλ ∼ 206 A W(-1) under 1.5 μW cm(-2) illumination at λ = 633 nm, Vg = 0 V, and Vds = 10 V.