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Field effect transistors based on 2D layered material have gained significant potential in emerging technologies, such as neuromorphic computing and ultrafast memory response for artificial intelligence applications. This study proposes a facile approach to fabricate an optoelectronic artificial synapse for neuromorphic computing and light‐decoding information system by utilizing the 2D heterostructure of CrSBr/PtS2 to overcome circuit complexity. The CrSBr layer serves as a trapping layer, while PtS2, mounted on top of CrSBr, acts as a channel layer. PtS2 exhibits n‐type semiconductor behavior with a hysteresis that varies with the thickness of the underlying CrSBr layer. The heterostructure device, featuring a 96.3 nm thick CrSBr layer, exhibited a large memory window of 11.9 V when the gate voltage is swept from −10 V to +10 V. Various synaptic behaviors are effectively demonstrated, including paired‐pulse facilitation, excitatory postsynaptic current, optical spike number and intensity‐dependent plasticity using laser light at a wavelength of 365 nm. The device achieves 26 distinct output signals depending on the intensity of the incident laser light, ranging from 10 to 385 mW cm−2, enabling its applications for light‐decoded information security systems. Thus, the investigation presents a unique approach to artificial intelligence and cybersecurity systems. [ABSTRACT FROM AUTHOR]

In recent years, silicon‐based room temperature Terahertz (THz) detectors have become the most optimistic research area because of their high speed, low cost, and unimpeded compatibility with mainstream complementary metal‐oxide‐semiconductor (CMOS) device technologies. However, Silicon (Si) suffers from low responsivity and high noise at THz frequencies. In this review, the recent advances in Si‐based THz detectors using silicon‐on‐insulator (SOI) substrates are presented. These offer several advantages over bulk counterparts, such as reduced parasitic capacitance, enhanced electric field confinement, and improved thermal isolation. The different types of THz detectors exploiting SOI substrate, such as conventional metal‐oxide‐semiconductor field effect transistors (MOSFETs), junction‐less MOSFETs, junction‐less nanowires field effect transistors (JLNWFETs), micro‐electromechanical system (MEMS), metal‐semiconductor‐metal (MSM) structures, and single electron transistor (SET), are discussed, and their key performances in terms of responsivity, noise equivalent power (NEP), bandwidth, and dynamic range are compared. The challenges and opportunities for further improvement of SOI THz detectors, such as device scaling, integration, and modulation, are also highlighted. This review may offer compelling evidence supporting the idea that SOI THz detectors have the potential to facilitate high performance, low power consumption, and scalability—qualities essential for advancing next‐level technologies. [ABSTRACT FROM AUTHOR]

To overcome the von Neumann bottleneck between memory and computing, the novel architectures with computing in‐memory are paid much attention and expected to be compatible with digital logic computing and/or analog brain‐inspired neuromorphic computing. Herein, by combining the Ba0.6Sr0.4TiO3 (BST) ferroelectric film and MoS2 layered semiconductor, a non‐volatile memory is constructed, which deliver the gate‐switchable function between the digital and analog functionality modes. The on/off ratio, subthreshold swing, and carrier mobility of MoS2/BST ferroelectric field‐effect transistor (FeFET) are 4.95×106, 68 mV dec−1, and 16.7 cm2 V−1 s−1, respectively. By a small electrical stimulation, the device demonstrates remarkable non‐volatile memory properties, including robust long‐term retention of ≈3000 s, superior endurance over 34 000 cycles, low operating energy at ≈0.3 pJ per spike. By a large electrical stress, it exhibits well memristive behavior and gating history dependent accumulation/diminution effect, which is attributed to the charge dynamic trapping/de‐trapping activation at the MoS2/BST interface. Following the historic memory behaviors, a cryptosystem is developed with auto‐generated reading log which is tamper‐resistant at hardware level. Moreover, the synaptic functions are realized on the device such as the short‐term potentiation/depression and gating‐depending synaptic plasticity. This study shows the opportunities of multi‐functionalities integration in a single FeFET device. [ABSTRACT FROM AUTHOR]

Accurate and rapid quantification of cytokines in biofluids is crucial for early disease diagnosis, management, and prevention. However, it still remains challenging for existing sensors due to the broad dynamic range of cytokines and high interference from sample matrices. To overcome these challenges, electrochemical (EC) and field‐effect transistor (FET) dual‐mode biosensing is integrated on an extended‐gate carbon nanotube field‐effect transistor. This biosensor chip effectively eliminates direct contact between the device and the solution and employs independent signal readouts based on two distinct response mechanisms, thereby circumventing the limitations associated with conventional transistor biosensors. Selective detection of cytokine (e.g., Interferon‐γ, IFN‐γ) is achieved by the FET sensing mode (0.1 to 4000 pg mL−1, with a limit of detection of 24.1 fg mL−1) and the EC sensing mode (0.4–2000 ng mL−1) at different concentration range. The feasibility of real sample analysis using the EC‐FET dual‐mode biosensor is confirmed by detecting salivary levels of IFN‐γ. The combination of EC and FET sensing modes not only provides high sensitivity and a wide response range (seven orders of magnitude) to accommodate various biological samples but also improves the reliability of detection results, which shows promising applications in biological analysis and early disease diagnosis. [ABSTRACT FROM AUTHOR]

As widely used commercial sensors, amperometric biosensors based on electrochemical (EC) reactions exhibit good linearity and reproducibility but suffer from a low dynamic range and poor limit of detection (LoD). In contrast, biosensors utilizing field‐effect transistors (FETs) demonstrate a wide detection range and ultralow LoDs but are susceptible to interferences or ionic strength influences and have poor quantitative accuracy due to their nonlinear response mechanism. Here, EC and carbon nanotube (CNT) FET‐based biosensors are integrated into one chip via a compatible fabrication process. The dual‐mode biosensing chip (DMSC) provides the advantages from both the EC biosensors and FET biosensors; these advantages include high reliability and accuracy for quantitatively detecting glucose, a dynamic detection range spanning 6 orders of magnitude, and a detection limit of 1 fM. The introduction of a time‐division multiplexing detection method enables the DMSC to carry out complementary detection of the same target, providing early warning of specific abnormal biomarkers and accurate determination of their concentration in real time. The DMSC approach is generally applicable to the detection of other biomarkers and provides exciting opportunities for more accurate self‐monitoring diagnostics in real situations. [ABSTRACT FROM AUTHOR]

Unipolar p‐ and n‐type organic field‐effect transistors (OFETs) are essential for constructing organic circuits and complementary designs crucial for high‐performance electronics. Traditionally, fabricating these transistors requires separate p‐type and n‐type organic semiconductors (OSCs), which complicates the process due to intricate patterning, protection of the first OSC layer, and considerable material wastage. In this work, an innovative approach is introduced, inspired by silicon transistor fabrication to obtain unipolar OFETs, employing a single ambipolar OSC in conjunction with doped organic semiconductor films (DOSCFs) as electrodes. This results demonstrate that OFETs with DOSCF electrodes suppress ambipolarity dramatically and achieve on/off ratios that are two to three orders of magnitude higher than those with metal electrodes, along with excellent stability. The unipolar characteristics of the devices are attributed to the unique work function properties and the intrinsic charge carrier behavior of the DOSCF electrodes. Significantly, inverter circuits utilizing these unipolar transistors outperformed traditional ambipolar transistors with metal electrodes, achieving a fivefold increase in voltage gain. This novel strategy promises to enhance the practicality and economic viability of organic electronics, paving the way for more sustainable and high‐performance circuit designs. [ABSTRACT FROM AUTHOR]

Ferroelectric field effect transistors (FeFETs), characterized by their low power consumption and polarization effect, can be employed in photodetectors based on 2D materials. In this paper, a MoS2 phototransistor with epitaxial ferroelectric (Hf0.5Zr0.5)O2 (HZO) is reported as a gate dielectric layer. Gate‐dielectric‐polarization‐dependent ambipolar behavior is observed in the FET, and relatively low power consumption and hysteresis‐free loop are achieved in the FeFET. The anomalous negative photoconductivity (NPC) is observed as well. Possible reasons for such phenomenon are clarified including the photogating effect originating from the interface traps and the polarization‐dependent electric‐field control through ferroelectric gating. The high responsivity of −8.44 × 103 A W−1 in the negative photoconductivity as well as the response time of 500 ms are reported. The demonstrated Molybdenum disulfide (MoS2) FeFET photodetectors show great potential in the on‐chip complementary metal‐oxide semiconductor (CMOS)‐compatible circuits for multifunctional devices. [ABSTRACT FROM AUTHOR]

Highcarrier concentration and low mobility in Bi2Se3 hide thetopological surface states (TSS). In the 2D ternary topological insulator (TI) Bi2–xSbxSe3,compensatory Sb doping regulates the carrier concentration and mobility withambipolar performance, together with the ultrathin thickness; these factorsmake the TSS in the 2D ternary TI Bi2–xSbxSe3 more observable. Here, a chemical vapor deposition (CVD) method is provided for synthesizing ultrathin Sb‐doped Bi2Se3 nanoplates with dimensions of 2–126 nm in thickness, 3–100 µm in lateral size, and an average Sb doping ranging from 0.15 ≤ x ≤ 0.75. Bi2–xSbxSe3 field effect transistors and Hall devices are manufactured to determine the carrier concentration and mobility of the obtained Bi2–xSbxSe3 nanoplates. These findings demonstrate that the 2D carrier concentration for Bi2–xSbxSe3 nanoplates can decrease up to 1.6 × 1012 cm–2. Furthermore, field‐effect mobility and Hall mobility of up to 3411 cm2 V–1s–1 and 6462 cm2 V–1 s–1, respectively, are realized. A strong ambipolar field effect is found in low‐carrier‐density Bi2–xSbxSe3 nanoplates, proving that these nanostructures may be freely controlled in terms of carrier type and concentration. The synthesis of high‐quality Bi2–xSbxSe3 nanoplates with low‐carrier concentration and high‐mobility provides a platform for investigating TI characteristics more clearly. [ABSTRACT FROM AUTHOR]

Two‐dimensional non‐layered tellurene (Te) can serve as a promising candidate in transistor applications because of its high carrier mobility and air stability. However, it is still quite challenging in aspect of ultra‐thin channel and gate‐control ability in conventional metal‐oxide‐semiconductor field‐effect transistor architecture. This work proposes a facile thinning strategy for solution‐proceed Te flakes and fabricates a junction field‐effect transistor (JFET) architecture, that has well addressed the above‐mentioned two issues. Through a mild oxidative thinning process, the post‐growth Te flakes are thinned from bulk to few‐layer, guaranteeing the highly efficient electrostatic doping as a transistor channel. Then, a four‐terminal JFET‐based on p‐Te and n‐ReS2 is designed, achieving a multifunctional integration of rectification diode, p‐ and n‐channel transistor in one single device. By accessing different contact scheme, the ReS2/Te p‐n diode is explored with a rectification ratio of 103, the p‐channel JFET exhibits a high hole mobility of 317.6 cm2V−1s−1, ideal low subthreshold swing of 84 mV dec−1. While the n‐channel JFET is obtained with electron mobility of 67.6 cm2 V−1s−1 and SS of 229 mV dec−1. Both p‐ and n‐channel devices showcase clear saturation characteristic with ultra‐small pinch‐off voltage (≈0.4 V), which is crucial for low‐power logical and integrated circuit applications. [ABSTRACT FROM AUTHOR]

2D semiconductors have emerged as candidates for next‐generation electronics. However, previously reported 2D transistors which typically employ the gate‐first process to fabricate a back‐gate (BG) configuration while neglecting the thorough impact on the dielectric capping layer, are severely constrained in large‐scale manufacturing and compatibility with complementary metal–oxide–semiconductor (CMOS) technology. In this study, dual‐gate (DG) field‐effect transistors have been realized based on wafer‐scale monolayer MoS2 and the gate‐last processing, which avoids the transfer process and utilizes an optimized top‐gate (TG) dielectric stack, rendering it highly compatible with CMOS technology. Subsequently, the physical mechanism of TG dielectric deposition and the corresponding controllable threshold voltage (VTH) shift is investigated. Then the fabricated TG‐devices with a large on/off ratio up to 1.7 × 109, negligible hysteresis (≈14 mV), and favorable stability. Additionally, encapsulated TG structured photodetectors have been demonstrated which exhibit photo responsivity (R) up to 9.39 × 103 A W−1 and detectivity (D*) ≈2.13 × 1013 Jones. The result paves the way for future CMOS‐compatible integration of 2D semiconductors for complex multifunctional IC applications. [ABSTRACT FROM AUTHOR]

Van der Waals ferroelectric semiconductors, which encompass both ferroelectricity and semiconductivity, have garnered intensive research interests for developing novel non‐volatile functional devices. Previous studies focus on ferroelectricity characterization and device demonstration, with little attention paid to the fundamental electronic properties of these materials and their functional structures, which are essential for both device design and optimization. In this study, scanning microwave impedance microscopy (sMIM) is utilized to investigate the ferroelectric semiconductor of α‐phase indium selenide (α‐In2Se3) and its synaptic field effect transistors. α‐In2Se3 nanoflakes of varying thicknesses are visualized through capacitive signal detection, whose responses are consistent with finite element simulations manifesting dependence on both flake thickness and its semiconductor property. sMIM spectroscopy performed on α‐In2Se3‐based metal‐oxide‐semiconductor (MOS) structures reveals typical MOS capacitance‐voltage characteristics, with additional hysteresis arising from the ferroelectric switching of α‐In2Se3. The local conductance state changes of synaptic α‐In2Se3 ferroelectric semiconductor transistors (FeSFET) in response to gate voltage stimuli are effectively detected by in situ sMIM, in good agreement with electrical device transport properties. This work deepens the understanding of ferroelectric semiconductor physics toward their practical device application. [ABSTRACT FROM AUTHOR]

The amelioration of atomically thin ferroelectric materials is imperative for next‐generation outperformed two‐dimensional (2D) electronics, which is elusive by their bulk counterparts. These remarkable materials' ferroelectric and piezoelectric features are the fundamental urges in optoelectronics, electronics, and energy harvesting. In this work, 2D ferroelectric Bi2O2Se flakes have been synthesized using a modified chemical vapor deposition technique. The 6 nm thick Bi2O2Se flake provides a robust ferroelectric switching under an applied voltage of ±10 V by piezoresponse force microscopy, further confirmed by first principles. Leveraging the successful growth, the high‐quality Bi2O2Se flakes permit the fabrication of a field‐effect transistor (FET) with state‐of‐the‐art performance. The FET device rewards a high current on–off ratio of 108 and field effect mobility of almost 131 cm2 V−1 s−1, owing to the small carrier effective mass of 0.2 m0. Combined, the electric field‐induced local polarization of ferroelectric switching and unprecedented device performance of Bi2O2Se semiconductors are certified for their utilization in advanced nanoelectronics and miniaturization of multifunctional devices with multifunctionalities. [ABSTRACT FROM AUTHOR]

The escalating environmental impact of pollution and the imperative to reduce carbon emissions have heightened the significance of developing biobased materials from natural biomass for electronic devices. This study investigates the utilization of biofermentation‐produced recombinant spider silk and animal‐derived hemin to create a novel biobased electret for field‐effect transistor memory. A critical challenge arises from the incompatibility between natural photoresponsive molecules and insulating biomaterials, resulting in severe phase separation that compromises film quality and morphology uniformity. This study systematically examines the effects of various film deposition and manufacturing techniques on the biobased electret's morphology, phase separation, and performance. Different methods demonstrate distinct advantages in terms of molecular aggregation/segregation, morphological homogeneity, and device performance. Phototransistor memory devices fabricated using spin coating and spray coating techniques exhibit robust aggregations and high memory windows of ≈30 V. Conversely, devices produced through solution shearing and electrospinning methods display enhanced smooth morphologies and high photoresponsivity. The phototransistor memory comprising electrospun fibers holds the potential to achieve the highest memory ratio, reaching ≈105. These findings not only highlight the applications of biobased materials through scalable film deposition processes but also underscore the importance of refining their morphology, phase separation, and performance in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Exploitation of low‐dimensional metal‐oxide semiconductor nanowires (MOS NWs) with peculiar and radial coaxial architectures is of great significance for constructing nanoscale, high‐performance, multi‐module integrable functional electronic products. Here, highly ordered In2O3@ZnO coaxial NW arrays (CNWA) using a simple and economical electrospinning technique are synthesized and assembled into field‐effect transistors (FETs). Featuring strong carrier effusion efficiency at the In2O3@ZnO circular heterogeneous interface, the field effect mobility (εFE) gets an intrinsic improvement and can reach as high as 202.3 cm2 V‒1 s‒1 for high‐k‐based CNWA FETs, which exceeds the performance of oxide‐based FETs devices reported by far. Furthermore, the unique structural advantages endowing In2O3@ZnO CNWA FETs with excellent optoelectronic coupling capabilities are identified, for which further optoelectronic detection and artificial photonic synaptic devices are constructed and functional simulations are implemented. This work offers new insights in designing optoelectronics and artificial synapses to process and recognize information for neuromorphic computing and artificial intelligence applications. [ABSTRACT FROM AUTHOR]

The visual system is crucial for human perception and learning, and the retina is responsible for pre‐processing visual information. Mimicking the neurobiological functions of the retina provides the basis for neuromorphic vision hardware. Here, an optogenetics‐inspired prototype capable of modifying neuron‐spiking behavior in a retina‐like manner is demonstrated. In addition to basic information processing, neuronal signal transmission in the retina is bio‐faithfully emulated using optical modulation, that is, neuronal firing is inhibited in the dark and activated upon illumination. The proposed single threshold‐switch field‐effect transistor optoelectronic neuron features an ultra‐compact design by integrating a gate‐modulated 2D MoS2 channel with a volatile threshold switch, and optoelectronic performance is achieved through a multi‐physics resistance‐matching mechanism. This study provides a promising pathway toward highly scalable and hierarchically designed spiking electronics, expanding the spectrum of neuromorphic hardware applications in the emerging field of biomimetic vision. [ABSTRACT FROM AUTHOR]

Fatal pathogenic organisms have been detected by various point‐of‐care tests (PoCTs) in clinical samples. PoCTs based on portable electrical devices are able to detect organisms in simple and rapid method. Although electrical PoCT devices show ultra sensitivity when detecting pathogens in standard samples, their industrialization has been limited due to low reproducibility, sensitivity, and specificity, resulting from nonspecific binding issues by media. In this research, a perpendicular N‐heterocyclic carbene self‐assembled monolayer (NHC‐SAM) conjugated on graphene micropattern field‐effect transistors (NGMFETs) is first demonstrated for monitoring pathogens. Two single bonds of NHCSAM on GM are investigated via density functional theory (DFT) and surface analyses. Bioreceptors are conjugated on the side gate‐modulated NGMFET for ultra‐stable on‐site detection. The side‐gated BNGMFETs system displayed remarkable performance in the detection of the following: i) SARS‐CoV‐2 spike protein S1 (limit of detection (LOD): ≈10 pg mL−1) in CTM, ii) O. tsutsugamushi Ab (LOD: ≈1 pg mL−1), and iii) E. coli (LOD: 10° CFU mL−1) in serum. Compared to commercial methodology, the platform presents 102 times higher LODs towards those pathogens in clinical samples with higher reproducibility. Based on these results, side‐gated BNGMFETs can be utilized as universal PoCT during pandemics. [ABSTRACT FROM AUTHOR]

The rapid development in information technologies necessitates rapid advancements of their supporting hardware. In particular, new computing paradigms are needed to overcome the bottleneck of traditional von Neumann architecture. Bottom‐up innovation, especially at the materials and devices level, has the potential to disrupt existing technologies through their emergent phenomena. As a new type of conceptual device, 2D ferroelectric field‐effect transistor (FeFET) is highly sought after due to its potential integration with modern semiconductor processes. Its low power consumption, area efficiency, and ultra‐fast operation provide an extra edge over traditional technologies. This review highlights recent developments in 2D FeFET, covering their device construction, working mechanisms, 2D ferroelectric polarization mechanism, multi‐functional applications and prospects. In particular, the combination of 2D semiconductor and ferroelectric dielectric materials for multi‐functionality applications is discussed. This includes non‐volatile memories (NVM), neural network computing, non‐volatile logic operation, and photodetectors. As a novel device platform, 2D semiconductor and ferroelectric interfaces are bestowed with a plethora of emergent physical mechanisms and applications. [ABSTRACT FROM AUTHOR]

Graphene has attracted considerable interest for next‐generation electronics. However, the absence of natural bandgap has limited the current on/off ratio of graphene‐based transistors. Vertical integration of 2D heterostructures offers a promising approach to address this challenge, enabling high‐current‐density vertical field‐effect transistor (VFET) with large on/off ratio. Here, a triboelectric potential‐powered VFET with a vertical stacked graphene/MoS2 heterostructure and a sliding‐mode triboelectric nanogenerator (TENG) coupled with gate dielectrics are proposed. The tribotronic VFET has an ultrashort channel length in vertical direction, exhibiting excellent current driving capability with an ultrahigh on‐state current density of 950 A cm−2 and a good current on/off ratio of 630. It also demonstrates reconfigurable diode behavior with a rectification ratio over 102. Temperature‐dependent studies are applied to tribotronic devices for the first time, indicating an effective modulation on the Schottky barrier height of 150 meV by the triboelectric potential. A green LED pixel is driven by the tribotronic VFET as a demonstration to work as a tactile interactive light‐emitting device. The demonstrated tribotronic vertical device offers a promising strategy for integrating various 2D layered materials with TENG in vertical direction, enabling 3D integration of low‐power and interactive devices for next‐generation electronics. [ABSTRACT FROM AUTHOR]

Optoelectronic synapses with information sensing, processing, and memory function are promoting the development of artificial visual perception systems. However, optoelectronic synapses' relatively inferior optoelectronic performance impedes their application in complex neuromorphic computing. Herein, optoelectronic synapses based on 3D graphene/molybdenum disulfide (MoS2) heterostructure field‐effect transistors are developed by using the double stress layer self‐rolled‐up method. The graphene, with excellent electrical properties, enhances the carrier transport capacity of the device. The unique continuous photoconductivity of MoS2 is suitable for simulating various synaptic nerve morphological functions. Meanwhile, the 3D resonant microcavity is added to enhance the optical field and make the device polarization sensitive, which reveals more intangible features of objects. The device demonstrates room‐temperature photodetection at ultraviolet, visible, near‐infrared, and mid‐infrared regions, with photoresponsivity up to 105 A W−1 at 590 nm. Furthermore, multiple synaptic neuromorphic functions, such as inhibitory postsynaptic current, paired‐pulse facilitation, short‐term depression, and long‐term depression, are successfully emulated. Here a new concept is provided for designing high‐performance optoelectronic synapses with polarization sensitivity and excellent potential in artificial intelligence is shown. [ABSTRACT FROM AUTHOR]

Electrical signatures for quantum magnetic phases of α‐RuCl3 sensed by an adjacent graphene field‐effect transistor (FET) are reported. The gate‐voltage dependence of the graphene FET reveals p‐type doping beneath α‐RuCl3 caused by the charge transfer due to the work function difference. Furthermore, the gate‐voltage hysteresis exhibits a marked change in the transport behavior with the temperature variation. The high‐T simple paramagnetic phase and the low‐T zigzag antiferromagnetic phase of α‐RuCl3 exhibit negligible hysteresis. In sharp contrast, a huge hysteresis of the graphene FET at intermediate temperatures is observed. The possibility that the observed conductance hysteresis is associated with the intriguing continuum excitations of the thermally induced Kitaev paramagnet state is discussed. The results show that the proximity effect‐based electric approach can be utilized for investigating charge‐neutral quasiparticles in quantum magnetic insulators. [ABSTRACT FROM AUTHOR]

A chlorine‐doped ultrathin phase of hafnium disulfide (HfS2) is proposed as an ideal candidate material for 2D field‐effect transistor (FET) device applications, down to the extreme sub‐5 nm miniaturization limit. This transition metal dichalcogenide 2D material is designed to combine features of both a metal and a semiconductor, exhibiting a high electric conductivity comparable with ordinary metals, that can be abruptly cut down via gating due to an energy gap immediately below the Fermi level and its anomalous metallic properties. These unique features enable realizing an alternative design of a FET device in which electrode and channel are made of the same Cl‐doped ML HfS2 phase, a potential breakthrough bypassing all issues associated with electronic (Schottky) and structural dis‐homogeneities or low conductivity that have hindered progress in this field. This material/design combination shall lead to a FET device with purely ohmic behavior, high metallic conductance, no interfacial contact resistance, and facile gating with extremely high on/off ratio. [ABSTRACT FROM AUTHOR]

A wearable sensor capable of directly detecting cytokines in external secretions external to the human body is pivotal for gauging the intensity of the immune response and circumventing inflammatory storms, a significant clinical concern. The detection of low‐concentration cytokines is often hampered due to interference from impurities in secretions. Addressing this challenge, a wearable detection system is developed by integrating a Janus membrane with water auto‐collection/filtering capabilities, and aptamer‐modified graphene field‐effect transistor sensors, enabling the detection of low‐concentration cytokines in undiluted sweat samples. The Janus membrane can automatically filter external secretions and transport them to the sensor surface, effectively eliminating impurity interference and enhancing the sensor's detection capabilities. The device can sensitively detect cytokines (such as TNF‐α, a marker for inflammation and cancer) in undiluted sweat, with a detection range spanning 0.5 to 500 pM, and a detection limit reaching 0.31 pM. The ultra‐flexibility of the sensor is also verified, maintaining stable electrical properties even after enduring up to 50 extreme deformations. These findings indicate that the wearable detection system has the potential to realize low‐concentration cytokines monitoring in the sweat of inflammatory patients, to assist the healthcare system in controlling the body's immune status. [ABSTRACT FROM AUTHOR]

Recently, there has been considerable interest in 2D Janus transition metal dichalcogenides owing to their unique structure that exhibits broken mirror symmetry along the out‐of‐plane direction, which offers fascinating properties that are applicable in various fields. This study investigates the issue of process instability in Janus MoSSe, which is mainly caused by its nonzero net dipole moments. It systematically investigates whether the built‐in dipole moments in Janus MoSSe make it susceptible to delamination by most polar solvents and increase its vulnerability to intense moisture adsorption, which leads to the deterioration of its semiconducting properties. To address these issues, as an example of device applications, field‐effect transistors (FETs) based on a van der Waals heterostructure are devised, where the bottom h‐BN (top h‐BN) insulating material is employed to prevent delamination (adsorption of moisture). The fabricated FETs exhibit improved electron mobility and excellent stability under ambient conditions. [ABSTRACT FROM AUTHOR]

Metal oxide field‐effect transistors (MOFETs) represent a promising technology for applications in existing but alsoemerging large‐area electronics. Simultaneously, the rise of 1D nanomaterials with unique properties, represented by nanofibers (NFs), has also energized research. Thus, developing 1D nanofiber networks (NFNs) to act as the potential building blocks for use in fundamental elements of transistors is considered to be a promising approach torealize high‐performance 1D electronics. However, high processing temperatures and disordered nanofiber distribution represent two remaining technical challenges. Here, electrospun highly aligned IGZO (a‐IGZO) nanofiber arrays with low‐thermal‐budget of 350 °C and impressive device characteristics are achieved, including a μFE of 5.63 cm2 V–1 s–1 and superior on/off current ratio of ≈107. When ALD‐derived high‐k HfAlOx thin films are employed as gate dielectrics, the source/drain voltage (VDS) can be substantially reduced by ten times to a range of only 03 V, along with a three times improvement in mobility to a respectable value of 15.9 cm2 V–1 s–1. Successful integrations of logic operation, sensor, and flexible devices implies the potential prospect of a‐IGZO NFN FETs in multifunctional electronics. The strategy for combining cryogenic processes and parallel arrays provides a feasible and reliable route in building future low‐power, high‐performance flexible electronics. [ABSTRACT FROM AUTHOR]

PbS QDs/a‐IGZO based sensitized photo field‐effect transistors are promising candidate for next‐generation near‐infrared photodetectors due to their ultra‐high sensitivity, gate tunability, and ease of integration. However, the reported PbS QDs/a‐IGZO based devices are all dependent on the solid‐state ligand exchange, and are troubled by problems such as poor repeatability, poor air stability, and negative influence on the transfer characteristic curve. In this article, for the first time, optimized high‐quality PbI2 capped PbS QDs films prepared by the solution‐phase ligand exchange are applied to PbS QDs/a‐IGZO sensitized Photo‐FETs. The device not only gets rid of the tedious layer‐by‐layer deposition, but also exhibits a detectivity of 9.3 × 1012 Jones, a responsivity of 45.3 A W−1 and a decay time of 24.6 ms (@1064 nm, 1.89 mW cm−2). The operation mode of the sensitized device can meet different detection requirements by adjusting gate voltage. Importantly, the responsivity of the unencapsulated PbS‐I based device remained unchanged after six months air exposure, demonstrating excellent air stability. [ABSTRACT FROM AUTHOR]

The gradual channel approximation forms the foundation for the analysis of field‐effect transistors. It has been used to discuss transistors that are not necessarily based on the field‐effect as well, such as the organic electrochemical transistor (OECT). Here, the applicability of the gradual channel approximation for OECTs is studied by a 2D drift‐diffusion model. It is found that OECT switching can be described by two separate effects—a doping/dedoping mechanism and the formation of an electrostatic double layer at the interface between the mixed conductor and the electrolyte. The balance between these two mechanisms is determined by the morphology of the mixed conductor, in particular the question if ions move in the same phase and electric potential as the holes, or if separate ion and hole phases are formed. It is argued that the gradual channel approximation can only be used to describe electrostatic switching at the mixed conductor/electrolyte interface (the two‐phase model), but cannot be employed to analyze devices operating on a doping/de‐doping mechanism (the one‐phase model). [ABSTRACT FROM AUTHOR]

Bitterness elicits unpleasant sensations in humans, which can hinder the acceptance of foods and medication adherence. Therefore, identifying and masking bitter tastes is crucial for developing palatable foods and promoting medication compliance in the food and pharmaceutical industries. To achieve this, employing agonism and antagonism of bitter taste receptors as effective strategies at the molecular level is essential. In this study, a bioelectronic tongue is developed to characterize the agonism and antagonism of bitter taste receptors. The human bitter taste receptors hTAS2R16 and hTAS2R31 are produced using an Escherichia coli expression system and reconstituted into nanodiscs (NDs). Subsequently, hTAS2R16‐ and hTAS2R31‐NDs are immobilized on the surface of graphene field‐effect transistors (FETs) to construct bioelectronic tongues. The developed system sensitively detected the bitter agonists, salicin and saccharin, at concentrations as low as 100 fM, with high selectivity in real‐time. The dose‐dependent curves shifted and K values decreased by the antagonists of hTAS2R16 and hTAS2R31, indicating antagonism‐based masking of bitter taste. Therefore, the developed bioelectronic tongue holds promise for identifying bitter tastes and evaluating the masking of bitterness based on the agonism and antagonism of hTAS2Rs. [ABSTRACT FROM AUTHOR]

The ferroelectric negative capacitance (NC) draws a great deal of attention for low‐power negative capacitance field‐effect transistors (NCFET) and NC capacitors. The fabrication of steep‐slope FET (subthreshold swing < 60mVdec−1) is reported, followed by modeling approaches. While the device fabrication favors a ferroelectric gate structure without interlayer metal, many NCFET models adopt interlayer metal between the ferroelectric layer and metal–insulator–semiconductor structure. The metal interlayer averages out spatial variation in the ferroelectric polarization, enabling a compact charge‐based relation between the layers. In addition, the approach assumes that the NC effect emerges from the ferroelectric layer regardless of the metal interlayer, which is not necessarily probable. This work reinvestigates the possible NC effect in ferroelectric–dielectric capacitors connected by a metal interlayer. The experiment confirms that the NC effect in the metal–ferroelectric–dielectric–metal structure does not appear in the metal–ferroelectric–metal–dielectric–metal structure. These results are inconsistent with the multidomain‐1D Landau–Ginzburg‐Devonshire model. In contrast, the suppression of the NC effect in the structure is fully explained by the advanced inhomogeneous stray‐field energy model, which simulates the dynamic evolution of polarization and screening charges. Therefore, an NCFET with a metal interlayer is impractical. [ABSTRACT FROM AUTHOR]

Negative photoconductance (NPC) detectors have attracted continuous attention for constructing advanced and novel optoelectronic devices, including reconfigurable image sensors and optosynaptic systems, especially by combining NPC with positive photoconductance (PPC). However, NPC devices suffer from much lower photosensitivity, slower response speed, and poor stability, especially in the infrared range. In this work, controllable NPC detectors based on organic-gated carbon nanotube field-effect transistors (OG-CNT FETs) are reported and the strong influence of light-induced electrostatic doping on the nonconventional photoresponse is demonstrated. The PM6/Y6-based heterojunction allows efficient near-infrared light absorption and facilitates exciton diffusion. By introducing a floating gate structure with an ultrathin dielectric layer, the OG-CNT FET shows an enhanced NPC effect owing to in situ signal amplification. Compared to other device configurations, the optimal OG-CNT FETs exhibit high responsivity of 72.6 A W-1 at 880 nm, along with improved response/recovery times of 7 and 5 ms. Impressively, gate-tunable switching between NPC and PPC is observed under the same light illumination. The reversible switching can be attributed to the competition between the light-controlled electrostatic coupling and the PM6/Y6 photovoltaic effect, which offers a new approach to achieve bidirectional photoresponses and paves the way for the development of future multifunctional optoelectronic systems. [ABSTRACT FROM AUTHOR]

Optically switchable field‐effect transistors (OSFETs) are non‐volatile photonic memory devices holding a great potential for applications in optical information storage and telecommunications. Solution processing of blends of photochromic molecules and π‐conjugated polymers is a low‐cost protocol to integrate simultaneously optical switching and charge transport functions in large‐area devices. However, the limited reversibility of the isomerization of photochromic molecules due to steric hindrance when embedded in ordered polymeric matrices represents a severe limitation and it obliges to incorporate as much as 20% in weight of the photochromic component, thereby drastically diluting the electronic function, limiting the device performance. Herein, a comparative study of the photoresponsivity of a suitably designed diarylethene molecule is reported when embedded in the matrix of six different polymer semiconductors displaying diverse charge transport properties. In particular, this study focuses on three semi‐crystalline polymers and three quasi‐1D polymers. It is found that 1% w/w of 1,2‐bis(5‐(3,5‐di‐tert‐butylphenyl)‐2‐methylthiophen‐3‐yl)cyclopent‐1‐ene in a blend with poly(indacenodithiophene‐co‐benzothiadiazole) is sufficient to fabricate OSFETs combining photo‐modulation efficiencies of 45.5%, mobilities >1 cm2 V−1s−1, and photo‐recovered efficiencies of 98.1%. These findings demonstrate that quasi‐1D polymer semiconductors, because of their charge transport dominated by intra‐molecular processes, epitomize the molecular design principles required for the fabrication of high‐performance OSFETs. [ABSTRACT FROM AUTHOR]

Graphene field‐effect transistors (G‐FETs) have attracted widespread attention in disease diagnosis, benefiting from these advantages of high sensitivity, label‐free, easy integration, and direct detection of nucleic acids (NAs) in liquid environments. However, the problem of nonspecific signals in G‐FETs is not fundamentally solved due to a lack of systematic theoretical research to support the development of effective solutions. Thus, researchers have to rely on speculative mechanisms to minimize nonspecific signals in experiments as much as possible. Herein, the nonspecific signal mechanism caused by eight types of π–π interaction paths mediated by aromatic rings is theoretically determined. Based on theoretical simulation results, the feasibility of blocking nonspecific signal paths through Nafion functionalization methods is experimentally verified. Experiments confirm that Nafion‐modified G‐FETs (NMG‐FETs) have excellent performance in avoiding nonspecific signals compared to traditional G‐FETs. Furthermore, the NMG‐FET achieves ultra‐sensitive detection of Down syndrome–related DNA down to 1 aM and severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) RNA down to 5 aM, and shows good specificity in base recognition. This study is expected to promote the theoretical advancement of the nonspecific signal mechanism in G‐FET NA detection and offer a practical strategy for improving signal purity and accuracy. [ABSTRACT FROM AUTHOR]

Next‐generation shortwave infrared (SWIR) imaging systems generally require a multidimensional information sensing capability (including intensity, wavelength, polarization, phase, etc.), a highly integrated photodetector unit, and information processing, allowing for miniaturization and low‐cost production. However, traditional polarized SWIR imaging systems with integrated polarizer arrays as supplementary filters and silicon‐based amplifying circuits are complicated and very expensive. Here, a SWIR polarization‐sensitive photodetector and a monolithic integrated polarization amplification system (MIPAS) based on well‐aligned carbon nanotube (CNT) arrays are demonstrated. The polarization‐sensitive CNT photodetector exhibits anisotropic ratios of ≈5.18 and ≈7.56 at 1800 and 2000 nm wavelengths, respectively, and high‐resolution characteristics that can be utilized to image SWIR laser spots with a radius of less than 10 µm. Furthermore, MIPAS including a CNT field‐effect transistor, a CNT loading resistor, and a polarization‐sensitive CNT photodetector is used to increase the anisotropic ratio of the CNT photodetector. The amplified anisotropic ratio is improved up to 173 and 243 at 1800 and 2000 nm wavelengths, respectively, which is the maximum reported in the SWIR band. Our work demonstrates that the CNT polarization‐sensitive photodetector has the potential for SWIR polarization imaging with a monolithic integrated polarization amplification system. [ABSTRACT FROM AUTHOR]

In‐memory computing, particularly neuromorphic computing, has emerged as a promising solution to overcome the energy and time‐consuming challenges associated with the von Neumann architecture. The ferroelectric field‐effect transistor (FeFET) technology, with its fast and energy‐efficient switching and nonvolatile memory, is a potential candidate for enabling both computing and memory within a single transistor. In this study, the capabilities of an integrated ferroelectric HfO2 and 2D MoS2 channel FeFET in achieving high‐performance 4‐bit per cell memory with low variation and power consumption synapses, while retaining the ability to implement diverse learning rules, are demonstrated. Notably, this device accurately recognizes MNIST handwritten digits with over 94% accuracy using online training mode. These results highlight the potential of FeFET‐based in‐memory computing for future neuromorphic computing applications. [ABSTRACT FROM AUTHOR]

Development of artificial mechanoreceptors capable of sensing and pre‐processing external mechanical stimuli is a crucial step toward constructing neuromorphic perception systems that can learn and store information. Here, bio‐inspired artificial fast‐adaptive (FA) and slow‐adaptive (SA) mechanoreceptors with synapse‐like functions are demonstrated for tactile perception. These mechanoreceptors integrate self‐powered piezoelectric pressure sensors with synaptic electrolyte‐gated field‐effect transistors (EGFETs) featuring a reduced graphene oxide channel. The FA pressure sensor is based on a piezoelectric poly(vinylidene fluoride‐trifluoroethylene) (P(VDF‐TrFE)) thin film, while the SA pressure sensor is enabled by a piezoelectric ionogel with the piezoelectric‐ionic coupling effect based on P(VDF‐TrFE) and an ionic liquid. Changes in post‐synaptic current are achieved through the synaptic effect of the EGFET by regulating the amplitude, number, duration, and frequency of tactile stimuli (pre‐synaptic pulses). These devices have great potential to serve as artificial biological mechanoreceptors for future artificial neuromorphic perception systems. [ABSTRACT FROM AUTHOR]

Field‐effect transistors‐based biosensors (bio‐FETs) have been considered an important technology for label‐free and ultrasensitive point‐of‐care diagnostics. However, practical applications using bio‐FETs are limited due to the trade‐off between sensing reliability and sensitivity. This study suggests a reliable and sensitive bio‐FETs based on nanoporous molybdenum disulfide (MoS2) channels encapsulated by a non‐planar high‐k aluminum oxide (Al2O3) dielectric layer. Nanoporous MoS2 thin film is fabricated with an abundant edge area and periodically ordered nanopores via block copolymer lithography. The ultra‐thin Al2O3 dielectric layer deposited along the nanoporous structure of the MoS2 realizes effective electrostatic control of charged biomolecules over the MoS2 channel. In addition, it plays important roles in not only enhancing the electrical performance of the nanoporous MoS2 bio‐FETs, that is, mobility, hysteresis, and subthreshold swing, but also achieving effective biomolecular immobilization on the device surface. The nanoporous MoS2 channel structure surrounded by non‐planar Al2O3 detects a prostate cancer biomarker with an ultra‐low limit of detection of 1 fg mL−1. Moreover, the excellent selectivity, high sensitivity, and clinical reliability of the nanoporous MoS2 bio‐FETs are also confirmed. The proposed device platform provides new insights and technical advances in the field of FETs based sensors for future point‐of‐care devices. [ABSTRACT FROM AUTHOR]

The unique properties of 2D‐materials like graphene are exploited in various electronic devices. In sensor applications, graphene shows a very high sensitivity, but only a low specificity. This shortcoming can be mastered by using heterostructures, where graphene is combined with materials exhibiting high analyte selectivities. Herein, this study demonstrates the precise deposition of nanoporous metal‐organic frameworks (MOFs) on graphene, yielding bilayers with excellent specificity while the sensitivity remains large. The key for the successful layer‐by‐layer deposition of the MOF films (SURMOFs) is the use of planar polyaromatic anchors. Then, the MOF pores are loaded with ionic liquid (IL). For functioning sensor devices, the IL@MOF films are grown on graphene field‐effect transistors (GFETs). Adding a top‐gate electrode yields an ion‐gated GFET. Analysis of the transistor characteristics reveals a clear Dirac point at low gate voltages, good on‐off ratios, and decent charge mobilities and densities in the graphene channel. The GFET‐sensor reveals a strong and selective response. Compared to other ion‐gated‐FET devices, the IL@MOF material is relatively hard, allowing the manufacturing of ultrathin devices. The new MOF‐anchoring strategy offers a novel approach generally applicable for the functionalization of 2D‐materials, where MOF/2D‐material hetero‐bilayers carry a huge potential for a wide variety of applications. [ABSTRACT FROM AUTHOR]

Field‐effect transistors‐based biosensors (bio‐FETs) have been considered an important technology for label‐free and ultrasensitive point‐of‐care diagnostics. However, practical applications using bio‐FETs are limited due to the trade‐off between sensing reliability and sensitivity. This study suggests a reliable and sensitive bio‐FETs based on nanoporous molybdenum disulfide (MoS2) channels encapsulated by a non‐planar high‐k aluminum oxide (Al2O3) dielectric layer. Nanoporous MoS2 thin film is fabricated with an abundant edge area and periodically ordered nanopores via block copolymer lithography. The ultra‐thin Al2O3 dielectric layer deposited along the nanoporous structure of the MoS2 realizes effective electrostatic control of charged biomolecules over the MoS2 channel. In addition, it plays important roles in not only enhancing the electrical performance of the nanoporous MoS2 bio‐FETs, that is, mobility, hysteresis, and subthreshold swing, but also achieving effective biomolecular immobilization on the device surface. The nanoporous MoS2 channel structure surrounded by non‐planar Al2O3 detects a prostate cancer biomarker with an ultra‐low limit of detection of 1 fg mL−1. Moreover, the excellent selectivity, high sensitivity, and clinical reliability of the nanoporous MoS2 bio‐FETs are also confirmed. The proposed device platform provides new insights and technical advances in the field of FETs based sensors for future point‐of‐care devices. [ABSTRACT FROM AUTHOR]

The pandemic of coronavirus disease 2019 (COVID‐19) reflects the great significance of rapid and accurate detection of pathogens by new sensing technologies. Antibody based biosensors with high sensitivity comparable to golden standard polymerase chain reaction (PCR) and miniaturized device features allow the detection of pathogens in portable and flexible formats. Herein, flexible metal oxide electrolyte‐gated field‐effect transistors (EGFETs) are reported to serve as the biosensors for rapid and ultrasensitive severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) detection. The semiconducting layer of the EGFETs associates with hybrid material of PEI doped metal oxides that not only improves the transistor performance, but also regulates microstructure forming higher surface‐to‐volume ratio, which brings more antibodies immobilization, resulting in higher sensitive, and faster response for detecting SARS‐CoV‐2. Comprehensive studies of materials and interfacing engineering of the EGFETs not only build the strong foundation for the EGFET sensors to show excellent sensitivity with a limit of detection from 0.14 fg ml−1 for SARS‐CoV‐2 S1 proteins, and 0.09 copies µl−1 for SARS‐CoV‐2 viruses, but also offer good mechanical properties to enable thin, soft flexible sensing platforms. This work provides a new strategy from materials to devices as innovative schemes for virus/pathogens detection. [ABSTRACT FROM AUTHOR]

Due to its unique band structure and topological properties, the 2D topological semimetal exhibits potential applications in photoelectric detection, polarization sensitive imaging, and Schottky barrier diodes. However, its inherent large dark current hinders the further improvement of the performance of the semimetal‐based photodetectors. In this study, a van der Waals (vdWs) field effect transistor (FET) composed of semimetal PdTe2 and transition metal dichalcogenides (TMDs) WSe2 is fabricated, which exhibits high sensitivity photoelectric detection performance in a wide band from visible light (405 nm) to mid‐infrared (5 µm). The dark current and the noise level in the device are greatly suppressed by the effective control of the gate. Benefiting from the extremely low dark current (1.2 pA), the device achieves an optical on/off ratio up to 106, a high detectivity of 9.79 × 1013 Jones and a rapid response speed (219 and 45 µs). This research demonstrates the latent capacity of the 2D topological semimetal/TMDs vdWs FET for broadband, high‐performance, and miniaturized photodetection. [ABSTRACT FROM AUTHOR]

Organic thin films deposited from solution attract wide interest for next‐generation (opto‐)electronic and energy applications. During solvent evaporation, the phase evolution dynamics for different components at different locations are not synchronic within the incrementally concentrated liquid films, determining the final anisotropic morphology and performance. Herein, by examining tens of widely investigated optoelectronic organic films, the general existence of composition wave propagating along the surface‐normal direction upon solidification is identified. The composition wave is initiated by a few nanometers thick surface mesophase kinetically forming at the foremost stage of phase transition, and afterward propagates toward the substrate during solvent evaporation. The composition waves exhibit well‐defined wave properties, including spatial wavelength, period, amplitude, and propagation velocity. These wave properties are closely correlated with the evaporation rate and the diffusion rate of organic molecules, which determines the dynamically varied local composition gradient along the surface‐normal direction. Such composition waves are commonly found for more than 80% of randomly examined solution‐processed thin films for high‐performance organic electronic devices including photovoltaic cells and field‐effect transistors. [ABSTRACT FROM AUTHOR]

Growth and characterization of metal‐oxide thin films foster successful development of oxide‐material‐integrated thin‐film devices represented by metal‐oxide‐semiconductor field‐effect transistors (MOSFET), drawing enormous technological and scientific interest for several decades. In recent years, functional oxide heterostructures have demonstrated remarkable achievements in modern technologies and provided deeper insights into condensed‐matter physics and materials science owing to their versatile tunability and selective amplification of the functionalities. One of the most critical aspects of their physical properties is the polar perturbation stemming from the ionic framework of an oxide. By engineering and exploiting the structural, electrical, magnetic, and optical characteristics through various routes, numerous perceptive studies have clearly shown how polar perturbations advance functionalities or drive exotic physical phenomena in complex oxide heterostructures. In this review, both intrinsic (engraved by thin‐film heteroepitaxy) and extrinsic (reversibly controllable defect‐mediated disorder and polar adsorbates) elements of polar perturbations, highlighting their abilities for the development of highly tunable functional properties are summarized. Scientifically, the recent approaches of polar perturbations render one to consolidate a prospect of atomic‐level manipulation of polar order in epitaxial oxide thin films. Technologically, this review also offers useful guidelines for rational design to heterogeneously integrated oxide‐based multi‐functional devices with high performances. [ABSTRACT FROM AUTHOR]

Ferroelectric (FE) control of magnetism at nanoscale, for instance, FE control of the polarity of spin‐polarized current is crucial for technological advances in magnetoelectric and spintronic applications. However, this fascinating functionality has not been reported in nanoscale systems yet. Herein, a new class of FE/A‐type antiferromagnetic heterobilayer/FE van der Waals (vdW) multiferroic structures is found, in which the FE control of polarity of spin‐polarized current is found possible. Take Sc2CO2/CrSiTe3/CrGeTe3/Sc2CO2 heterostructure as a successful example. First‐principles calculations reveal that its polarity of half‐metallicity can be switched by flipping the FE polarization orientation. Meanwhile, device transport simulation shows that its up/down spin current transmission ratio is as large as 0.1 × 103 at P→↑↑\[\mathop {\rm{P}}\limits^ \to \uparrow \uparrow \] Sc2CO2 configuration and is only 2.6 × 10−3 at P→↓↓$\mathop {\rm{P}}\limits^ \to \downarrow \downarrow $ Sc2CO2 configuration in the vdW multiferroic heterostructures. Essentially, it stems from the reversible FE switch of the internal electric field across the CrSiTe3/CrGeTe3 heterobilayer and the FE control of the interfacial effect between Sc2CO2 and Cr(Si/Ge)Te3 layers. This work opens a direction for constructing low‐energy‐dissipation, non‐volatile, and high‐sensitive spintronic devices such as spin field‐effect transistors. [ABSTRACT FROM AUTHOR]

Biomarkers are primary indicators for precise diagnosis and treatment. The early identification of health biomarkers has been sustained by the evolutionary success in sensor technologies. Among them, graphene field‐effect transistor (GFET) biosensors have exhibited major advantages such as an ultrashort response time, high sensitivity, easy operation, capability of integration, and label‐free detection. Owing to the atomic thickness, graphene restricts charge carrier flow merely at the material surface and responds to foreign stimuli directly, leading to effective signal acquisition and transmission. Here, this review summarizes the latest advances in GFET biosensors in a comprehensive manner that contains the device design, working principle, surface functionalization, and proof‐of‐concept applications. It provides a comprehensive survey of GFET biosensors with regard to biomarker analysis at the single‐device level and integrated prototypes that include wearable sensors, biomimetic systems, healthcare electronics, and diagnostic platforms. Moreover, there is discussion on the long‐standing research efforts and outlook for the future development of GFET sensor systems from lab to fab. [ABSTRACT FROM AUTHOR]

Even though atomically thin 2D semiconductors have shown great potential for next‐generation electronics, the low carrier mobility caused by poor metal–semiconductor contacts and the inherently high density of impurity scatterings remains a critical issue. Herein, high‐mobility field‐effect transistors (FETs) by introducing few‐layer PdSe2 flakes as channels is achieved, via directly depositing semimetal antimony (Sb) as drain–source electrodes. The formation of clean and defect‐free van der Waals (vdW) stackings at the Sb–PdSe2 heterointerfaces boosts the room temperature transport characteristics, including low contact resistance down to 0.55 kΩ µm, high on‐current density reaching 96 µA µm−1, and high electron mobility of 383 cm2 V−1 s−1. Furthermore, metal–insulator transition (MIT) is observed in the PdSe2 FETs with and without hexagonal boron nitride (h–BN) as buffer layers. However, the layered h–BN/PdSe2 vdW stacking eliminates the interference of interfacial disorders, and thus the corresponding device exhibits a lower MIT crossing point, larger mobility exponent of γ ∼ 1.73, significantly decreased hopping parameter of T0, and ultrahigh electron mobility of 2,184 cm2 V−1 s−1 at 10 K. These findings are expected to be significant for developing high mobility 2D‐based quantum devices. [ABSTRACT FROM AUTHOR]

For epidemic prevention and control, molecular diagnostic techniques such as field‐effect transistor (FET) biosensors is developed for rapid screening of infectious agents, including Mycobacterium tuberculosis, SARS‐CoV‐2, rhinovirus, and others. They obtain results within a few minutes but exhibit diminished sensitivity (<75%) in unprocessed biological samples due to insufficient recognition of low‐abundance analytes. Here, an electro‐enhanced strategy is developed for the precise detection of trace‐level infectious agents by liquid‐gate graphene field‐effect transistors (LG‐GFETs). The applied gate bias preconcentrates analytes electrostatically at the sensing interface, contributing to a 10‐fold signal enhancement and a limit of detection down to 5 × 10−16 g mL−1 MPT64 protein in serum. Of 402 participants, sensitivity in tuberculosis, COVID‐19 and human rhinovirus assays reached 97.3% (181 of 186), and specificity is 98.6% (213 of 216) with a response time of <60 s. This study solves a long‐standing dilemma that response speed and result accuracy of molecular diagnostics undergo trade‐offs in unprocessed biological samples, holding unique promise in high‐quality and population‐wide screening of infectious diseases. [ABSTRACT FROM AUTHOR]

The correlations between semiconductor type and gas sensing properties in soluble acene/polymer blends have not yet been examined. Here, the phase separation mechanism in pseudo‐liquid phase blend film is investigated and an unusual solid‐state morphology that is effective for amperometric gas sensing performance is demonstrated. In 6,13‐bis(triisopropylsilylethynyl) pentacene (TIPS–pentacene)/poly(fluorine‐co‐triarylamine) (PTAA) blend, two phases are uniformly mixed, without being completely phase‐separated due to the similar solubility and surface tension. On the other hand, in 2,8‐difluoro‐5,11‐bis(triethylsilylethynyl) anthradithiophene (diF–TES ADT)/PTAA blend, the diF−TES ADT molecules are segregated both at the air–film, and film–substrate interfaces, and subsequently crystallized with a high degree of crystal perfection. In the meanwhile, Marangoni‐flow induces crater‐like via hole structure of PTAA at the middle layer. In situ measurement of (ultraviolet–visible) UV–vis absorption spectra and computational calculation reveal kinetics of liquid–solid–crystal transition in relation to the functional groups of soluble acene. Interestingly, flow driven hole structure of PTAA in diF–TES ADT/PTAA blend film allows the target NO2 gas to selectively penetrate the channel region, thereby enhancing sensitivity toward NO2, while decreasing affinity with other gases. The results provide protocols for fabricating highlperformance field‐effect transistors and gas sensors in a blending system. [ABSTRACT FROM AUTHOR]

2D semiconductors have shown great potentials for ultra‐short channel field‐effect transistors (FETs) in next‐generation electronics. However, because of intractable surface states and interface barriers, it is challenging to realize high‐quality contacts with low contact resistances for both p‐ and n‐ 2D FETs. Here, a graphene‐enhanced van der Waals (vdWs) integration approach is demonstrated, which is a multi‐scale (nanometer to centimeter scale) and reliable (≈100% yield) metal transfer strategy applicable to various metals and 2D semiconductors. Scanning transmission electron microscopy imaging shows that 2D/2D/3D semiconductor/graphene/metal interfaces are atomically flat, ultraclean, and defect‐free. First principles calculations indicate that the sandwiched graphene monolayer can eliminate gap states induced by 3D metals in 2D semiconductors. Through this approach, Schottky barrier‐free contacts are realized on both p‐ and n‐type 2D FETs, achieving p‐type MoTe2, p‐type black phosphorus and n‐type MoS2 FETs with on‐state current densities of 404, 1520, and 761 µA µm−1, respectively, which are among the highest values reported in literature. [ABSTRACT FROM AUTHOR]

The emergence of infectious diseases that are quickly spreading, like the coronavirus (COVID‐19), necessitates the development of efficient biosensors that can quickly detect and identify pathogens. It is essential to create sensitive virus detection methods in order to stop a virus from spreading throughout the world. It is determined that field‐effect transistors (FETs) made of nanomaterials are potential candidates for rapid virus identification due to how easily the electronic transport characteristics of such an atomically thin nanomaterial can be affected by perturbations. Various FETs in this review article are investigated that are based on nanoparticles, carbon nanotubes (CNT), graphene, graphene‐oxide, and semiconducting transition metal dichalcogenides (TMDs) WSe2 in order to show that they are promising biosensors in regards to quickly and precisely detect COVID‐19. The conjugation of nanomaterials with proteins enables the direct delivery of antiviral agents to the host cells. This method also minimizes the off‐target effects and enables the targeted interactions. This mechanism has produced encouraging results in regards to sensing or treating COVID‐19. The high surface area and extremely small size of nanomaterials make them crucial in regards to the development of new detection methods. The point‐of‐care test method of detection is quick, simple, and user‐friendly, and it only requires a small amount of a patient's blood. It does not require a laboratory or trained professionals. This overview of the current research that is conducted on nanomaterials will prove to be useful in the process of formulating strategies for the diagnosis, treatment, and vaccination of viruses in opinion. Finally, the conclusion of this review provides a summary of the current challenges and the future prospects. [ABSTRACT FROM AUTHOR]

Complementary metal‐oxide‐semiconductor (CMOS) field‐effect transistors (FETs) are the key component of a chip. Bulk indium arsenide (InAs) owns nearly 30 times higher electron mobility µe than silicon but suffers from a much lower hole mobility µh (µe/µh = 80), thus unsuited to CMOS application with a single material. Through the accurate ab initio quantum‐transport simulations, the performance gap between the NMOS and PMOS is significantly narrowed is predicted and even vanished in the sub‐2‐nm‐diameter gate‐all‐around (GAA) InAs nanowires (NW) FETs because the inversion of the light and heavy hole bands occurs when the diameter is shorter than 3 nm. It is further proposed several feasible strategies for further improving the performance symmetry in the GAA InAs NWFETs. Short‐channel effects are effectively depressed in the symmetric n‐ and p‐type GAA InAs NWFETs till the gate length is scaled down to 2 nm according to the standards of the International Technology Roadmap for Semiconductors. Therefore, the ultrasmall GAA InAs NWFETs possess tremendous prospects in CMOS integrated circuits. [ABSTRACT FROM AUTHOR]

Controlling electron tunneling is of fundamental importance in the design and operation of semiconductor nanostructures such as field effect transistors (FETs) and quantum computing device architectures. The exponential sensitivity of tunneling with distance requires precise fabrication techniques to engineer the desired device dimensions to achieve the appropriate tunneling resistances/tunnel rates. This is particularly important for high fidelity spin readout and qubit exchange in quantum computing architectures. Here, it is shown by combining precision fabrication techniques with accurate atomistic modeling, predictive device design criteria are achieved at atomic length scales. Such a tool is useful when devices become more complex or have arbitrary shapes/geometries. In particular, in this study, atomic precision patterning of monolayer degenerately phosphorus‐doped silicon tunnel junctions patterned by scanning tunnelling microscopy lithography and tight‐binding non‐equilibrium Green's function (TB‐NEGF) modeling is combined to describe the dependence of tunnel junction resistance RT on junction length. An agreement with experiment to within a factor of 2 over 4 orders of magnitude in RT is found, and this model allows to accurately determine the barrier height V0 = 57.5 ± 1 meV and lateral seam sxy = 0.39 ± 0.01 nm in these nanoscale junctions. This study confirms the use of the TB‐NEGF formalism to accurately model highly doped atomically precise tunnel junctions in silicon. Further applications of this model will enable improved device performance at the nanoscale. [ABSTRACT FROM AUTHOR]