A range of novel two-dimensional materials have been actively explored for More Moore and More-than-Moore device applications because of their ability to form van der Waals heterostructures with unique electronic properties. However, most of the reported electronic devices exhibit insufficient control of multifunctional operations. Here, we leverage the band-structure alignment properties of narrow-bandgap black phosphorus and large-bandgap molybdenum disulfide to realize vertical heterostructures with an ultrahigh rectifying ratio approaching 10 and on-off ratio up to 10. Furthermore, we design and fabricate tunable multivalue inverters, in which the output logic state and window of the mid-logic can be controlled by specific pairs of channel length and, most importantly, by the electric field, which shifts the band-structure alignment across the heterojunction. Finally, high gains over 150 are achieved in the inverters with optimized device geometries, showing great potential for future logic applications.

An array of black-phosphorus photodetectors with channel lengths down to 100 nm is fabricated, and temperature-dependent photodetection measurements from 300 K down to 20 K are carried out. The devices show high photoresponse in a broadband spectral range with a record-high photoresponsivity of 4.3 × 10(6) A W(-1) at 300 K for the 100 nm device.

High-performance MoS2 transistors scaled down to 100 nm are studied at various temperatures down to 20 K, where a highest drive current of 800 μA μm(-1) can be achieved. Extremely low electrical noise of 2.8 × 10(-10) μm(2) Hz(-1) at 10 Hz is also achieved at room temperature. Furthermore, a negative differential resistance behavior is experimentally observed and its origin of self-heating is identified using pulsed-current-voltage measurements.

The alloys with composition of SmCo7−xZrx(x=0–0.8) were synthesized and characterized in the temperature range of 10–1273 K and at fields up to 5 T. The experimental results show that a small amount of Zr substitution can contribute to a stabilization of the TbCu7 structure, and improve magneto-anisotropy Ha from 90 kOe for x=0–180 kOe for x=0.5 at room temperature, and from 140 kOe for x=0–300 kOe for x=0.5 at 10 K. It is probable that Zr may partly replace a dumbbell of Co atom pair in these alloys. The phase transition between CaCu5, TbCu7, Th2Zn17, and Ce2Ni7 at different heat treatment conditions was also discussed.

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A new class of nanocrystalline alloys with composition Fe44Co44Zr7B4Cu1 has been developed. This and similar alloys of general composition (Fe, Co)–M–B–Cu (where M=Zr, Hf, Nb, etc.) have been named HITPERM. They offer large magnetic inductions and excellent soft magnetic properties at elevated temperatures. Thermomagnetic properties, permeability, and frequency dependent losses are described in this report. These alloys exhibit high magnetization that persists to the α→γ phase transformation at 980 °C. Alternating current permeability experiments reveal a high permeability at 2 kHz with a loss value of 1 W/g at Bs=10 kG and f=10 kHz.

Neuromorphic computing has the potential to accelerate high performance parallel and low power in-memory computation, artificial intelligence, and adaptive learning. Despite emulating the basic functions of biological synapses well, the existing artificial electronic synaptic devices have yet to match the softness, robustness, and ultralow power consumption of the brain. Here, we demonstrate an all-inorganic flexible artificial synapse enabled by a ferroelectric field effect transistor based on mica. The device not only exhibits excellent electrical pulse modulated conductance updating for synaptic functions but also shows remarkable mechanical flexibility and high temperature reliability, making robust neuromorphic computation possible under external disturbances such as stress and heating. Based on its linear, repeatable, and stable long-term plasticity, we simulate an artificial neural network for the Modified National Institute of Standards and Technology handwritten digit recognition with an accuracy of 94.4%. This work provides a promising way to enable flexible, low-power, robust, and highly efficient neuromorphic computation that mimics the brain.

a great challenge for top-gate RF device fabrication since atomic layer deposition (ALD) typically needs oxygen or water as precursor. [13][14][15] Even though recent research progress of capping BP with ALD high-κ dielectrics shows effective suppression of the black phosphorus surface oxidation, [16][17][18] this process still degrades the electric performance of BP transistors compared with the back-gate devices with minimal exposure to precursors. [19] As shown in previous studies, electric performance of BP FETs can be dominated by the channel dielectric interface where ALD high-κ dielectrics performs better than conventional SiO 2 . For instance, backgate BP transistors on high-κ substrate exhibit improved device performance in comparison with BP FETs on conventional SiO 2 . [11,20] Also, encapsulation by hexagonal boron nitride results in great enhancement of the hole mobility of BP. [6,21,22] However, this approach requires multiple dry transfer steps for both black phosphorus and hexagonal boron nitride flakes with precise alignment for a single device, and thus it has extremely low throughput and yield.In this paper, we report a new approach toward high-performance BP RF transistors using a Damascene-like planarization process to create an embedded gate stack with high-κ dielectrics, which enables high-quality interface while avoids the precursor exposure to the BP channel surface at the same time. [23,24] Side-by-side comparison with two conventional topgate structures shows at least twice improvement in the radio frequency performance of the embedded gate devices. Systematic studies of the radio frequency performance from room temperature down to 20 K are carried out for the first time.A record high extrinsic f max of 17 and 31 GHz for the device with 400 nm gate length has been achieved at room temperature and 20 K, respectively. The ratio of f max /f T has been improved to over two, a twice improvement over previous results, showing a significant advantage in power gains compared with graphene transistors. [23,24]