Search

With the popularization of electronic devices and the demand for portability, low-power consumption has become crucial for integrated circuit chips. Two-dimensional (2D) semiconductors offer significant potential in constructing low-power devices due to their ultrathin thickness, enabling fully depletion operation. However, fabricating these 2D low-power devices, such as negative-capacitance transistors or tunneling transistors, often requires multiple layers of gate dielectrics or channel band engineering, adding complexity to the manufacturing process and posing challenges for their integration with silicon technology. In this work, we have developed low-power MoS2 metal–semiconductor field effect transistors utilizing a standard metal–semiconductor contact, which eliminates the need for gate dielectrics and semiconductor heterojunctions. It demonstrates a sharp subthreshold slope (SS ∼ 64 mV/dec), a minimum operating gate voltage range (−0.5 ∼ 1 V), a minimum current hysteresis (3.69 mV), and a stable threshold voltage close to 0 V (Vth ∼ −0.27 V). Moreover, we implemented an inverter circuit with a high voltage gain of 47. [ABSTRACT FROM AUTHOR]

As one of the most important members of the two-dimensional (2D) chalcogenide family, MoS2 plays a fundamental role in the development of 2D electronic and optoelectronic designs. However, MoS2-based optoelectronic devices are hindered by their weak light–matter interactions, which make it challenging to achieve excellent device performance in photoelectronic memory applications. Here, we developed a multifunctional optoelectronic memory by coupling Au nanoparticles with MoS2, where the presence of Au nanoparticles on the surface significantly enhanced the light absorption capacity of MoS2 through the surface-plasmon-enhanced effect. The device achieved a photoresponse capability with a light current-to-dark current ratio exceeding 103, surpassing the majority of values reported for comparable photoconductive detectors. Importantly, it exhibits excellent light writing, storage, and erasuring capabilities, with a storage time exceeding 1000 s. Based on this device, a 3 × 3 array hardware core is designed to mimic human retinal imaging under the irradiation of 660, 532, and 457 nm lasers by using R-CNN algorithm, reducing power consumption, and redundancy. These advancements have the potential to drive future developments in neuromorphic electronics, particularly in optical information sensing and learning. [ABSTRACT FROM AUTHOR]

The integration of data storage and computing capabilities into a single physical component has led to the development of a microneuronal network system with high precision and speed rates. To achieve this system architecture, bold innovations in the underlying hardware structure and neural network architecture are required. This article introduces an optoelectronic storage device based on the MoS2/h-BN/graphene van der Waals heterojunction transistor. At room temperature, the transistor exhibits an electron mobility of up to 340 cm2/(V·s) and a large storage window due to its unique van der Waals heterojunction. The transistor's reconfigurable nonvolatile optoelectronic properties enable the construction of logic gates, including "AND", "OR", "NAND", and "NOR". Leveraging these logic gates, a microneural network system is created that simulates future machine vision applications. The system achieves a remarkable recognition rate of 96.3% for images in a multidimensional color space, demonstrating the significant development potential of the microneural network system based on the MoS2/h-BN/graphene vdW heterojunction transistor in future machine vision. [ABSTRACT FROM AUTHOR]

α-Synuclein (α-Syn) is a major biomarker of Parkinson's disease (PD). Concentration detection of α-Syn in cerebrospinal fluid and plasma of patients are used as a clue for early PD detection. Herein, we propose a thin-film transistor (TFT) biosensor based on an indium gallium zinc oxide (IGZO) thin film fabricated by the sol-gel method. The IGZO TFT biosensor is used for the early detection of PD after surface functionalization for α-Syn. The surface functionalization worked on the surface of the extended gate indium tin oxide sensing platform instead of the channel layer of TFT. Depending on concentrations of α-Syn in human cerebrospinal fluid and plasma, we diluted six different concentrations of α-Syn for detection, ranging from 1 pg ml−1 to 100 ng ml−1. The result shows that the biosensor exhibits high sensitivity and selectivity for α-Syn, a reliable sensing performance with a sensitivity of 189.9 mV dec−1, and a coefficient of determination R2 of 99.7% between 10 pg ml−1 and 100 ng ml−1. [ABSTRACT FROM AUTHOR]

Massive data processing with high computing efficiency and low operating power is required owing to the rapid development of artificial intelligence and information technology. However, the von Neumann structure computing system with the separated memory and processor can cause large energy consumption and a low running speed during massive data processing. Therefore, the brain‐inspired neuromorphic computing system is developed, that can provide hardware support for emulating biological synaptic functions and realizing highly intensive data processing with low power consumption. As a neuromorphic device, the optoelectronic synaptic device (OSD) is regarded as an ideal device to replace the von Neumann‐based computer because of its ultrafast signal transmission, large bandwidth, low energy consumption, and wireless communication. Owing to their unique optoelectronic property, metal halide perovskites (MHPs) have received growing attention as effective photosensitive materials in OSDs. Therefore, the review introduces the recent progress on OSDs based on MHPs (MHPs‐OSDs) including the structures and properties of MHPs, and the architectures and performance characteristics of MHPs‐OSDs. Furthermore, applications of MHPs‐OSDs are presented. Finally, the outlook and opportunity of MHPs‐OSDs are discussed. [ABSTRACT FROM AUTHOR]

In this work, In2O3 nanofibers were fabricated by electrospinning, and a field effect transistor (FET) based on In2O3 nanofibers was integrated. A hydroxyl-assisted strategy was proposed for both stability and performance enhancement for the FET. Hydrogen peroxide (H2O2) was added into a precursor solution for electrospinning. It is found that the stability of the FET is improved after H2O2 incorporation, while the mobility is decreased. Surprisingly, after UV irradiation, the FET with both high mobility and high stability was obtained. It is assumed that under UV irradiation, H2O2 is decomposed into highly reactive hydroxyl radicals (•OH), which contributes to the degradation of the polymer. XPS and FT-IR analysis verify that oxygen- and carbon-related defects can be removed through the hydroxyl-assistant strategy. Furthermore, the flexible FET based on In2O3 nanofibers with H2O2 addition and UV irradiation was fabricated on the PI substrate, and the high electrical performance is further demonstrated. This strategy makes it possible to fabricate the oxide nanofiber FET with both high mobility and high stability. [ABSTRACT FROM AUTHOR]

Electrolyte-gated synaptic transistors are promising for artificial neural morphological devices. However, few literatures have been reported regarding the manufacturing of electrolyte-gated synaptic transistors with low cost and biocompatible components. Here, the fully transparent synaptic transistors based on water-induced In2O3 thin films have been integrated by sol–gel method at low temperature, and lactose dissolved in citric acid solution is used as the gate electrolyte. The migration of the ions at the interface plays a crucial role in the potentiation and depression of the synaptic weight. In this work, the biological synaptic functions, including excitatory postsynaptic current, paired-pulse facilitation, high-pass filtering characteristics, short-term memory, and long-term memory, are mimicked. Meanwhile, based on the potentiation/depression behaviors of the synaptic transistor, a three-layer artificial neural network is applied for pattern recognition, and the recognition accuracy is as high as 94.6%. This study offers a possibility to realize fully transparent synaptic devices with biocompatible components at low temperature. [ABSTRACT FROM AUTHOR]

The formation of Ohmic contact between metal electrode and 2D semiconductor channel is considered a key factor for performance improvement of 2D metal–oxide–semiconductor field‐effect transistors (MOSFET). However, the Schottky barrier at the metal electrode/2D semiconductor interfaces cannot be lowered effectively due to the pinning effect of Fermi levels, which makes it hard to obtain lower Ohmic contact resistance. Until now, although physical transfer metal electrode or inserted tunneling layer has been reported to get rid of the Fermi‐level pinning effect, these different designs of electrode engineering are not systematically compared. To serve better Ohmic contact, three different designs of electrode engineering are employed in 2D MoS2 MOSFET: evaporating Ag electrode on MoS2, transferring MoS2 to Ag electrode, and inserting ultrathin AlOx tunneling layer. Our experimental results demonstrate that the transferring MoS2 to Ag electrode in 2D MoS2 MOSFET can obtain the lowest contact resistance and Schottky barrier of 0.45 Ωcm and 12.8 meV, respectively. On this basis, photodiodes with obvious rectifying behavior are fabricated using schemes of electrode engineering, due to their different Schottky barrier high. The detailed contrastive analysis in our three different designs of electrode engineering can provide valuable guidance to optimize the performance of 2D semiconductor MOSFET. [ABSTRACT FROM AUTHOR]

Emulating synaptic behavior using the three-terminal and ion-coupled transistors is considered as a promising strategy for the realization of neuromorphic devices. Meanwhile, one-dimensional (1-D) nanostructures show great potential for the fabrication of flexible electronic devices. In this work, 1-D indium oxide (In2O3) nanofibers were fabricated by the electrospinning (ES), and the flexible and compatible synaptic transistor based on In2O3 nanofibers was integrated on polyimide (PI) substrate. The synaptic behaviors, such as the short-term plasticity (STP) and long-term plasticity (LTP), are simulated by the synaptic transistor with chitosan solution as the gate dielectric. The fabricated synaptic transistor exhibits good biocompatibility and environmental compatibility, and the pattern recognition rate of the simulated device array by the Mixed National Institute of Standards and Technology (MNIST) database of the handwritten digits is confirmed to be as high as 92%. [ABSTRACT FROM AUTHOR]

Thin-film transistors (TFTs) with bilayer channels were used to improve the field-effect mobility and bias stress stability of the TFTs. Homogeneous structures were fabricated by the combination of a carrier deficient layer made of In2O3 thin film annealed in oxygen atmosphere (InO:O) and an electron injection layer made of In2O3 thin film annealed in air (InO:A). Compared with the InO:A/InO:A TFT with only air annealing, the field-effect mobility of InO:O/ InO:A TFT with two-step annealing process was improved from 0.04 to 5.11 cm2/Vs, the on/off current ratio was ameliorated from 4.6 × 105 to 7.6 × 107 A, while the VTH is decreased from 12.5 to 4.7 V under the positive bias stressing (PBS). It is confirmed that the excessive oxygen vacancies are produced by annealing the thin film in the air. The electrical performance of the InO:O/InO:A TFTs with two-step annealing process is greatly improved due to the formation of a low defect state and high carrier concentration electron transport layer, through the combination of the carrier transport layer and the carrier injection layer. These optimized electrical properties indicate an important step toward achieving transparent, high performance, and low-temperature metal oxides TFTs. [ABSTRACT FROM AUTHOR]

Relative humidity (RH) in storage environment has a great impact on the electrical performance of thin film transistors (TFTs), and the RH is critical for semiconductor manufacturing and device packaging. In this work, solution-processed indium oxide (In2O3) TFT is fabricated, and the electrical performance of the device is investigated after being exposed to various RH conditions. It is found that the threshold voltage (Vth) and the mobility of In2O3 TFT exhibit clear responses to the RH ranging from 23% to 85%. The inherent mechanism about the humidity effect on the electrical performance is elaborated, and this is due to the "donor effect" from the absorbed water molecules. In addition to the effect on Vth and mobility, RH also exhibits a significant effect on the electrical stability of the TFT. The experimental result indicates that the In2O3 TFT exposed to RH <50% exhibits excellent stability with an applied positive bias stressing for 2000s. [ABSTRACT FROM AUTHOR]

For field effect transistors (FETs) based on electrospun oxide nanofibers, the electrical stability can be deteriorated by high-temperature annealing treatment. In this work, the self-passivation of an In2O3 nanofiber FET is achieved by the consequent thermal treatment, water treatment, and deep ultraviolet (DUV) irradiation, and the FET is named as a TWD (thermal treatment-water treatment-DUV irradiation)-device. For comparison, the devices treated by thermal treatment and by thermal + water treatment were also fabricated and abbreviated as a T-device and a TW (thermal treatment-water treatment)-device, respectively. From the transfer characteristics of the T-, TW-, and TWD-devices, the electrical performance is first degraded by water treatment and then recovered after DUV irradiation. The positive bias stress test confirms the stability enhancement after TWD treatment, indicating the achievement of the self-passivated FET based on In2O3 nanofibers. The excellent electrical stability is owing to the structural relaxation and the removal of trap sites such as oxygen vacancy and hydroxide. Integrated with the high-k ZrO2 dielectric, the TWD-In2O3/ZrO2 FET exhibits further improved electrical performance, including a mobility of 3.35 cm2/V s and a high on/off current ratio of 107. [ABSTRACT FROM AUTHOR]