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Despite being widely investigated for their memristive behavior, ferroelectrics are barely studied as channel materials in field-effect transistor (FET) configurations. In this work, we use multilayer α-In2Se3 to realize a ferroelectric channel semiconductor FET, i.e., FeS-FET, whose gate-triggered and polarization-induced resistive switching is then exploited to mimic an artificial synapse. The FeS-FET exhibits key signatures of a synapse such as excitatory and inhibitory postsynaptic current, potentiation/depression, and paired pulsed facilitation. Multiple stable conductance states obtained by tuning the device are then used as synaptic weights to demonstrate pattern recognition by invoking a hidden layer perceptron model. Detailed artificial neural network (ANN) simulations are performed on binary scale MNIST data digits, invoking 784 input (28 × 28 pixels) and 10 output neurons which are used in the training of 42 000 MNIST data digits. By updating the synaptic weights with conductance weight values on 18 000 digits, we achieved a successful recognition rate of 93% on the testing data. Introduction of 0.10 variance of noise pixels results in an accuracy of more than 70% showing the strong fault-tolerant nature of the conductance states. These synaptic functionalities, learning rules, and device to system-level simulation results based on α-In2Se3 could facilitate the development of more complex neuromorphic hardware systems based on FeS-FETs.

Despite being widely investigated for their memristive behavior, ferroelectrics are barely studied as channel materials in field-effect transistor (FET) configurations. In this work, we use multilayer α-In

We report on the demonstration of visible/near-IR high-performance photodetector based on exfoliated $\beta $ -Indium selenide (In2Se3) on sapphire with a clear signature of band edge in spectral responsivity at a wavelength of ~850–900 nm. Room temperature photoluminescence (PL) measurements also indicated a peak at ~900 nm confirming the band-edge. Devices with inter-digitated metal-semiconductor-metal (MSM) geometry exhibited a responsivity of 3.8 A/W (normalized to device area). A low dark current of 0.80 nA and a photo to dark current ratio of ~52 were measured when illuminated with 650 nm A specific detectivity of $1 \times 10^{10}$ cm Hz $^{0.5}\,\,\text{W}^{-1}$ at 650 nm and $6 \times 10^{8}$ cm Hz $^{0.5}\,\,\text{W}^{-1}$ at the band-edge of 900 nm were estimated. These results indicate the promise of $\beta $ -(In2Se3) for visible/near-IR detector applications.

We report on the first demonstration of photodetector as well as the observation of photovoltaic effect based on vertical transport in multilayer $\alpha$ -In 2 Se 3 . A metal/ $\alpha$ -In2Se 3 /ITO vertical junction was used to achieve an ultra-high responsivity of 1000 A/W even at a low bias of 0.5 V with a clear band-edge corresponding to multilayer $\alpha$ -In 2 Se 3 . Additionally, an asymmetric barrier height arising out of ITO and Au contacts to vertical $\alpha$ -In 2 Se 3 resulted in photovoltaic effect with $\mathrm{V}_{\mathrm{OC}}\sim 0.1\mathrm{V}$ and $\mathrm{I}_{\mathrm{S}\mathrm{C}}\sim 0.4\mu \mathrm{A}$ under 520 nm illumination.

We report on a multi‐layer MoS2‐based low power synaptic transistor using Ta2O5 as a back‐gate dielectric for mimicking the biological neuronal synapse. The use of high‐k dielectric allows for a lower voltage swing compared to using conventional SiO2, thus offering an attractive route to low‐power synaptic device architectures. Exfoliated MoS2 is utilized as the channel material and the hysteresis in the transfer characteristics of the transistor is exploited to demonstrate Excitatory and Inhibitory postsynaptic currents, long term potentiation and depression (LTP/LTD), indirect Spike Timing Dependent Plasticity (STDP) based on single and sequential gate (Vg) pulses respectively. The synapse had achieved a 35% weight change in channel conductance within 15 electrical pulses for negative synaptic gate pulse and 28% change for positive synaptic gate pulse. We also demonstrate complete tunability of weight in the synapse by Spike Amplitude dependent plasticity (SADP) at a low voltage of 4V This article is protected by copyright. All rights reserved.

This work reports the very first systematic study on the physics of avalanche instability and SOA concerns in AlGaN/GaN HEMT using sub-μs pulse characterization, post stress degradation analysis, well calibrated TCAD simulations and failure analysis by SEM and TEM. Impact of electrical, as well as thermal effects on SOA boundary and avalanche instability are investigated. Trap assisted cumulative nature of degradation is studied in detail, which was discovered to be the root cause for avalanche instability in AlGaN/GaN HEMTs. Post failure SEM/TEM analysis reveal distinct failure modes in presence and absence of carrier trapping.

Herein, device demonstration based on vertical transport in multilayer I±-In2Se3 is reported. Photodetectors realized using a metal/I±-In2Se3/indium tin oxide (ITO) vertical junction exhibit clear signature of the band edge in spectral responsivity. The wavelength at 680 nm corresponding to an ultrahigh responsivity of 1000 A Wâ��1 and a detectivity of >1013 cm Hz0.5 Wâ��1 at a bias of 0.5 V. The variation of responsivity and detectivity with optical power density is studied, and a transient response of 20 ms is obtained for the devices (instrument limitation). In addition, an asymmetric barrier height arising out of ITO and Au contacts to a vertical I±-In2Se3 junction resulted in a photovoltaic effect with VOC â��0.1 V and ISC â��0.4 I¼A under an illumination of 520 nm.

We report on the highest responsivity for III-nitride Metal Semiconductor Metal solar-blind photodetectors on sapphire. Devices on unintentionally doped AlGaN epilayers grown by Metal Organic Chemical Vapor Deposition exhibited sharp absorption cut-off in the range of 245–290 nm. Very high responsivity >5 A/W at 10 V bias was achieved with visible rejection exceeding three orders of magnitude for front illumination. Compared to the responsivity values reported in the literature for state-of-the-art solar-blind photodetectors, this work presents the highest values of responsivity at a given bias and up to sub-250 nm detection threshold. The high responsivity is attributed to an internal gain mechanism operating on these devices. The reverse-bias leakage current across these samples was found to be dominated by thermionic field emission at low biases and Poole-Frenkel emission from a deep trap level (0.7 eV from the conduction band-edge for Al0.50Ga0.50 N) at high biases.