An ultra-sensitive NH gas sensor enabled by an ion-in-conjugated polycroconaine/TiCT core-shell composite.

MXenes are emerging sensing materials due to their metallic conductivity and rich surface chemistry for analytes; they, however, suffer from poor stability. Incorporation with functional polymers can largely prevent the performance decay and enhance the sensing performance. Herein, we demonstrate a core-shell composite, TiCT@croconaine (poly(1,5-diaminonaphthalene-croconaine), PDAC) prepared by a facile polymerization reaction, suitable for NH detection.

Highly Selective HS Gas Sensor Based on TiCT MXene-Organic Composites.

Cost-effective and high-performance HS sensors are required for human health and environmental monitoring. 2D transition-metal carbides and nitrides (MXenes) are appealing candidates for gas sensing due to good conductivity and abundant surface functional groups but have been studied primarily for detecting NH and VOCs, with generally positive responses that are not highly selective to the target gases. Here, we report on a negative response of pristine TiCT thin films for HS gas sensing (in contrast to the other tested gases) and further optimization of the sensor performance using a composite of TiCT flakes and conjugated polymers (poly[3,6-diamino-10-methylacridinium chloride--3,6-diaminoacridine-squaraine], PDS-Cl) with polar charged nitrogen.

Ultrafast photoresponse of vertically oriented TMD films probed in a vertical electrode configuration on Si chips.

Integrated photodetectors based on transition metal dichalcogenides (TMDs) face the challenge of growing their high-quality crystals directly on chips or transferring them to the desired locations of components by applying multi-step processes. Herein, we show that vertically oriented polycrystalline thin films of MoS and WS grown by sulfurization of Mo and W sputtered on highly doped Si are robust solutions to achieve on-chip photodetectors with a sensitivity of up to 1 mA W and an ultrafast response time in the sub-μs regime by simply probing the device in a vertical arrangement, , parallel to the basal planes of TMDs. These results are two orders of magnitude better than those measured earlier in lateral probing setups having both electrodes on top of vertically aligned polycrystalline TMD films.

Bioplastics and Carbon-Based Sustainable Materials, Components, and Devices: Toward Green Electronics.

The continuously growing number of short-life electronics equipment inherently results in a massive amount of problematic waste, which poses risks of environmental pollution, endangers human health, and causes socioeconomic problems. Hence, to mitigate these negative impacts, it is our common interest to substitute conventional materials (polymers and metals) used in electronics devices with their environmentally benign renewable counterparts, wherever possible, while considering the aspects of functionality, manufacturability, and cost. To support such an effort, in this study, we explore the use of biodegradable bioplastics, such as polylactic acid (PLA), its blends with polyhydroxybutyrate (PHB) and composites with pyrolyzed lignin (PL), and multiwalled carbon nanotubes (MWCNTs), in conjunction with processes typical in the fabrication of electronics components, including plasma treatment, dip coating, inkjet and screen printing, as well as hot mixing, extrusion, and molding.

Room temperature and high response ethanol sensor based on two dimensional hybrid nanostructures of WS/GONRs.

Here in this research, room temperature ethanol and humidity sensors were prepared based on two dimensional (2D) hybrid nanostructures of tungsten di-sulfide (WS) nanosheets and graphene oxide nanoribbons (GONRs) as GOWS. The characterization results based on scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (ESD), Raman spectroscopy and X-ray diffraction (XRD) analysis confirmed the hybrid formations. Ethanol sensing of drop-casted GOWS films on SiO substrate indicated increasing in gas response up to 5 and 55 times higher compared to pristine GONRs and WS films respectively.

A graphene/TiS heterojunction for resistive sensing of polar vapors at room temperature.

The room temperature polar vapor sensing behavior of a graphene-TiS heterojunction material and TiS nanoribbons is described. The nanoribbons were synthesized via chemical vapor transport (CVT) and their structure was investigated by scanning electron microscopy, high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Raman and Fourier transform infrared spectroscopies. The gas sensing performance was assessed by following the changes in their resistivities.

Computational investigation of gas detection and selectivity on TiS nanoflakes supported by experimental evidence.

Titanium trisulfide (TiS3), a transition metal chalcogenide, bears the potential to replace silicon, when taking the form of nanoflakes, due to its favorable band gap and optical response. In this paper, we investigate the response of TiS3 nanoflakes to gas detection through a careful quantum computational approach and a few succinct measurements. The computations are benchmarked and compared with a relevant experiment at each step, where their results/conclusions are discussed.

Electric and Photovoltaic Behavior of a Few-Layer α-MoTe2 /MoS2 Dichalcogenide Heterojunction.

Mo-based van der Waals heterojunction p-n diodes with p-type α-MoTe2 and n-type MoS2 are fabricated on glass, and demonstrate excellent static and dynamic device performances at a low voltage of 5 V, with an ON/OFF current ratio higher than 10(3) , ideality factors of 1.06, dynamic rectification at a high frequency of 1 kHz, high photoresponsivity of 322 mA W(-1) , and an external quantum efficiency of 85% under blue-light illumination.

Static and Dynamic Performance of Complementary Inverters Based on Nanosheet α-MoTe2 p-Channel and MoS2 n-Channel Transistors.

Molybdenum ditelluride (α-MoTe2) is an emerging transition-metal dichalcogenide (TMD) semiconductor that has been attracting attention due to its favorable optical and electronic properties. Field-effect transistors (FETs) based on few-layer α-MoTe2 nanosheets have previously shown ambipolar behavior with strong p-type and weak n-type conduction. We have employed a direct imprinting technique following mechanical nanosheet exfoliation to fabricate high-performance complementary inverters using α-MoTe2 as the semiconductor for the p-channel FETs and MoS2 as the semiconductor for the n-channel FETs.

High-gain subnanowatt power consumption hybrid complementary logic inverter with WSe2 nanosheet and ZnO nanowire transistors on glass.

A 1D-2D hybrid complementary logic inverter comprising of ZnO nanowire and WSe2 nanosheet field-effect transistors (FETs) is fabricated on glass, which shows excellent static and dynamic electrical performances with a voltage gain of ≈60, sub-nanowatt power consumption, and at least 1 kHz inverting speed.

Non-classical logic inverter coupling a ZnO nanowire-based Schottky barrier transistor and adjacent Schottky diode.

On a single ZnO nanowire (NW), we fabricated an inverter-type device comprising a Schottky diode (SD) and field-effect transistor (FET), aiming at 1-dimensional (1D) electronic circuits with low power consumption. The SD and adjacent FET worked respectively as the load and driver, so that voltage signals could be easily extracted as the output. In addition, NW FET with a transparent conducting oxide as top gate turned out to be very photosensitive, although ZnO NW SD was blind to visible light.

Molybdenum disulfide nanoflake-zinc oxide nanowire hybrid photoinverter.

We demonstrate a hybrid inverter-type nanodevice composed of a MoS2 nanoflake field-effect transistor (FET) and ZnO nanowire Schottky diode on one substrate, aiming at a one-dimensional (1D)-two-dimensional (2D) hybrid integrated electronic circuit with multifunctional capacities of low power consumption, high gain, and photodetection. In the present work, we used a nanotransfer printing method using polydimethylsiloxane for the fabrication of patterned bottom-gate MoS2 nanoflake FETs, so that they could be placed near the ZnO nanowire Schottky diodes that were initially fabricated. The ZnO nanowire Schottky diode and MoS2 FET worked respectively as load and driver for a logic inverter, which exhibits a high voltage gain of ∼50 at a supply voltage of 5 V and also shows a low power consumption of less than 50 nW.

A ZnO nanowire-based photo-inverter with pulse-induced fast recovery.

We demonstrate a fast response photo-inverter comprised of one transparent gated ZnO nanowire field-effect transistor (FET) and one opaque FET respectively as the driver and load. Under ultraviolet (UV) light the transfer curve of the transparent gate FET shifts to the negative side and so does the voltage transfer curve (VTC) of the inverter. After termination of UV exposure the recovery of photo-induced current takes a long time in general.