New Types Of Electronic Devices Research Articles

Principles, fabrication, and applications of halide perovskites‐based memristors

AbstractIn recent decades, the microelectronics industry has developed rapidly based on the von Neumann architecture and under the guidance of Moore's law. However, as the size of electronic devices approaches the limit and power consumption increases, traditional microelectronic materials and devices are facing more and more challenges. As a new type of semiconductor material, halide perovskites (HPs) have excellent photoelectric characteristics, such as high carrier mobility, controllable band structure, etc., which have been widely used in solar cells, light emitting diodes (LEDs), photodetectors, memristors, and in other fields. Among them, the memristor, as a new type of electronic device, is very promising for in‐memory computing with low power consumption by breaking the limit of von Neumann architecture. Especially, HPs‐based memristors show outstanding photoelectric response performance, low power consumption, and flexible wearability, allowing them to hold great application potential in logical operation, polymorphic storage, and neuromorphic computing, etc. In this review, we first briefly introduce the basic characteristics and preparation methods of HPs. Secondly, the development history, device structure, and performance parameters of memristors are depicted in detail. Thirdly, the resistance mechanism and application of HPs‐based memristors are discussed. Finally, the research status and development prospects of HPs‐based memristors are outlined.

Electrochemical-tunable and mesostructure-dependent abrupt-to-progressive conversion in fibroin-based transient memristor

The unique degradability and excellent biocompatibility make silk fibroin an attractive material for flexible transient memristors. Materials functionalization from the mesoscopic reconstruction view is a promising route to expand functions and create new types of electronic devices. Here, the transformation of the abrupt-to-progressive switching behavior in fibroin-based memristors is achieved via annealing to adjust the mesoscopic structure. Through electrical test and scanning electron microscope analysis, we study the electrochemical dynamics of metal nanoparticles in switching medium with different mesoscopic structures and directly reveal the microscopic origin of the abrupt-to-progressive transformation in fibroin-based transient memristors. The device exhibits abrupt resistive switching behaviors when the mobility and redox rate are high and displays progressive resistive switching behaviors under the low mobility and low redox rate condition. These findings reveal the microscopic origins of abrupt-to-progressive conversion and provide general guidance for designing high-performance memory devices and artificial synapses.

Ultrathin GaAs Photovoltaic Arrays Integrated on a 1.4 µm Polymer Substrate for High Flexibility, a Lightweight Design, and High Specific Power

Lightweight ultrathin solar cells with high efficiency and reliability serve as a convenient untethered power source for new types of electronic devices, such as attachable or implantable electronics, small-scale robots, and many others. However, the extreme mechanical properties of high-performance solar cells and ultrathin films present challenges when handling and processing them to realize ultrathin solar cell arrays. In this paper, a highly efficient GaAs photovoltaic array integrated on an ultrathin polymer film (1.4 µm thick) is presented. Full processes, including framing, cold-welding, epitaxial lift-off (ELO), and microfabrication, are used to realize ultra-flexible and lightweight GaAs photovoltaic arrays. The mechanical characteristics are analyzed via numerical and experimental methods along with demonstrations with electrically functional devices. The power-to-weight ratio (specific power: 5.44 W g−1) is in the highest range, even with single-junction solar cells.

Research review about the progress of transient electronics in sensor and electronic skin

Transient electronics, a new type of electronic device, is made of degradable materials. After a programmed set period of operations, transient electronics can be partially or completely degraded when they are subjected to certain stimulus. Transient electronics can work normally without extreme conditions, and can degrade immediately after stable operation. It could supplement the limitation of traditional electronics, and could be of great interest for applications in electronic skin and sensors.

Tailored Graphene Micropatterns by Wafer-Scale Direct Transfer for Flexible Chemical Sensor Platform.

2D materials, such as graphene, exhibit great potential as functional materials for numerous novel applications due to their excellent properties. The grafting of conventional micropatterning techniques on new types of electronic devices is required to fully utilize the unique nature of graphene. However, the conventional lithography and polymer-supported transfer methods often induce the contamination and damage of the graphene surface due to polymer residues and harsh wet-transfer conditions. Herein, a novel strategy to obtain micropatterned graphene on polymer substrates using a direct curing process is demonstrated. Employing this method, entirely flexible, transparent, well-defined self-activated graphene sensor arrays, capable of gas discrimination without external heating, are fabricated on 4 in. wafer-scale substrates. Finite element method simulations show the potential of this patterning technique to maximize the performance of the sensor devices when the active channels of the 2D material are suspended and nanoscaled. This study contributes considerably to the development of flexible functional electronic devices based on 2D materials.

Physical models for MoS2 and their application to simulations of MoS2 MSM device

MoS2 is a kind of two-dimensional semiconductor material with excellent electrical and optical properties, which can be used to develop new types of electronic devices and optoelectronic devices. Here, we established the mobility model of the MoS2. It is found that the simulation results agree with the experimental data. And our model are better than the theoretical results at low temperature. At the same time, we used the model to simulat the MoS2 MSM device. The I – V curve are basically identical with the measurement results, which proves the practicability of the model.

Enhancement of near infrared light sensing using side-gate modulation

The integration of nanostructures in electronic devices utilizes their unique quantum properties for realizing discrete measuring systems. Specifically, self-assembled organic monolayers and nanocrystals (NCs), together with bottom-up production methods, can lead to new types of electronic devices. In this work, we present a wavelength-tunable near-infrared detection device in which PbS NCs are used to create an optical gate for an AlGaAs/GaAs high electron mobility device. By integrating side gates, we were able to enhance light detection sensitivity by optimizing the conductivity of the channel. Both DC and AC modulations of the side gate were tested and compared in order to enhance the detector’s signal–to-noise ratio (SNR). Higher harmonic signals of the side gate modulation supply additional information about the detection mechanism.

Probing 2D black phosphorus by quantum capacitance measurements

Two-dimensional materials and their heterostructures have emerged as a new class of materials, not only for fundamental physics but also for electronic and optoelectronic applications. Black phosphorus (BP) is a relatively new addition to this class of materials. Its strong in-plane anisotropy makes BP a unique material for making conceptually new types of electronic devices. However, the global density of states (DOS) of BP in device geometry has not been measured experimentally. Here, we report the quantum capacitance measurements together with the conductance measurements on an hBN-protected few-layer BP (∼six layers) in a dual-gated field effect transistor (FET) geometry. The measured DOS from our quantum capacitance is compared with density functional theory (DFT). Our results reveal that the transport gap for quantum capacitance is smaller than that in conductance measurements due to the presence of localized states near the band edge. The presence of localized states is confirmed by the variable range hopping seen in our temperature dependence conductivity. A large asymmetry is observed between the electron and hole side. This asymmetric nature is attributed to the anisotropic band dispersion of BP. Our measurements establish the uniqueness of quantum capacitance in probing the localized states near the band edge, hitherto not seen in conductance measurements.

Nonlocal transport mediated by spin supercurrents

In thin film ferromagnets with perfect easy-plane anisotropy, the component of total spin perpendicular to the easy plane is a good quantum number and the corresponding spin supercurrent can flow without dissipation. In this Letter we explain how spin supercurrents couple spatially remote spin-mixing vertical transport channels, even when easy-plane anisotropy is imperfect, and discuss the possibility that this effect can be used to fabricate new types of electronic devices.

Simple and scalable route for the ‘bottom-up’ synthesis of few-layer graphene platelets and thin films

Graphene has generated much interest owing to its exceptional electronic properties and high mechanical strength. This has enabled new types of electronic devices and composite materials to be envisaged. The main problem is the availability of the material and the difficulties associated with its synthesis. Here we have used a simple, convenient and scalable chemical vapour deposition method involving sodium ethoxide in ethanol to produce few-layer graphene sheets or platelets. The process has the advantage that it can be used to grow graphene films on non-metal containing substrates such as silicon wafer and quartz glass and that all non-carbon by-products are soluble in water.

Nanoionics Switching Devices: “Atomic Switches”

AbstractNovel nanoionics devices, atomic switches, have been developed using a solid-electrochemical reaction to control the formation and annihilation of the metal filament between two electrodes. The switching operation can be achieved simply by the application of a bias voltage to precipitate metal atoms in a nanogap between the two electrodes or to dissolve them onto one of the electrodes. The small size of atomic switches enables rapid switching even though atomic motion is required. They also have several novel characteristics in that they are nonvolatile, consume less power, and have a simple structure and a low on-resistance. Logic gates and 1 kbit nonvolatile memory chips have been developed using atomic switches in order to demonstrate the possibilities for improving present-day electronic devices. Their characteristics also enable the fabrication of new types of electronic devices, such as high-performance programmable logic devices that may achieve a multitude of functions on a single chip.

Direct Assembly of Quantum Confined Nano-Particles

AbstractAdvances in nanoparticle technology enable the production of new types of electronic devices, catalytic systems and complex functional surface coatings. For most of these applications, random deposition or self-assembled arrangement of the particles on surfaces are sufficient. However, an increasing number of potential applications such as single electron transistors and quantum computers require exact placement of single nanoparticles with sub-10 nm resolution and specific size. Till date, techniques that provide an exact online placement of countable and size-selected nanoparticles for functional devices have not been reported. For this purpose a cluster-jet system, based on a gas-phase nanoparticle synthesis source, connected to a focussing collimator system has been developed. The objective of this technique is to assemble countable single nanoparticles with spatial resolution of 10 nm or below onto a pre-structured substrate. In the first stage of this system, nanoparticles in the size regime between 3 and 10 nm are synthesized in a lowpressure microwave plasma reactor. This reactor has the unique advantage of generating particles with defined size distribution, structure, morphology and low degree of agglomeration due to coulomb repulsion during particle formation and growth. Separated single particles are extracted by means of a particle laden molecular beam. A mass filter consisting of a particle mass spectrometer (PMS) coupled to the reactor is used to select nanoparticles of a specific size, according to their mass, charge and kinetic energy. In order to achieve the designated lateral resolution, the particle laden beam will be collimated by electromagnetic lenses and focused onto a pierced AFM-tip. Operation of the focusing mechanism and tip preparation have been successfully performed separatly and are currently being adapted to the use in the cluster-jet system. After completion, this technique is intended to enable the assembly of nanoparticles in almost any desired two-dimensional structure onto a substrate.

Covalent Coupling of Gold Nanoparticles to Multiwalled Carbon Nanotubes for Electronic Device Applications

AbstractCreating hybrid nanostructures of disparate nanoscale blocks is of interest of exploring new types of electronic devices and networks. Here, we demonstrate the novel coupling of gold nanoparticles of 3-4 nm diameters to sidewall of multiwalled carbon nanotubes (MWNTs) using the electroless plating technique. MWNTs were initially chemically modified with an H2SO4-HNO3 acid treatment, and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. When the activated MWNTs were immersed in a gold-containing electroless plating bath, gold deposition occurred at the catalytic sites. The deposited gold clusters then catalyze further gold deposition on the tube surface (autocatalytic process). Novel hybrid nanostructures with gold nanoparticles homogeneously distributed on MWNTs resulted. High-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS) were used to characterize the conjugation process.

Magneto-opto-electronic bistability in a phenalenyl-based neutral radical.

A new organic molecular conductor, based on a spiro-biphenalenyl neutral radical, simultaneously exhibits bistability in three physical channels: electrical, optical, and magnetic. In the paramagnetic state, the unpaired electrons are located in the exterior phenalenyl units of the dimer, whereas in the diamagnetic state the electrons migrate to the interior phenalenyl units and spin pair as a pi-dimer. Against all expectations, the conductivity increases by two orders of magnitude in the diamagnetic state, and the band gap decreases. This type of multifunctional material has the potential to be used as the basis for new types of electronic devices, where multiple physical channels are used for writing, reading, and transferring information.

Fabrication of the structure for qubits using electrons on liquid helium

In the previous papers, the system of qubits using electrons on a liquid helium film was described. In this paper we describe the physical realization of the system that we have begun to fabricate. We will not in this brief discussion describe how we intend to operate the system. We will show that we are nano- and micro-fabricating a new type of electronic device that differs from other microelectronic devices in that the final step of the fabrication deposits a layer of helium rather than some other dielectric. The operation of the device will differ in that it manipulates single electrons and it must operate at low temperatures.

Random potential device using quantum percolation phenomenon

We propose a new type of electronic device in which a quantum percolation phenomenon is utilized. We calculate steady-state wavefunctions in random potential systems by the steepest-descent method and made clear the relation between the correlation length of the wavefunction and the concentration and height of the random potentials. We find that the correlation length becomes minimum at an intermediate potential concentration which coincides with the classical percolation point in the case of low potential barriers. In the case of high potential barriers, the correlation length becomes minimum in a higher concentration region because of the decrease in the tunnelling probability of the electron through the random potential clusters. Finally, we investigate the appropriate concentration of random potentials for a switching device and find that the concentration should be 0.6 which is, in fact, the classical percolation concentration.

Field-Induced Nanometer- to Atomic-Scale Manipulation of Silicon Surfaces with the STM

The controlled manipulation of silicon at the nanometer scale will facilitate the fabrication of new types of electronic devices. The scanning tunneling microscope (STM) can be used to manipulate strongly bound silicon atoms or clusters at room temperature. Specifically, by using a combination of electrostatic and chemical forces, surface atoms can be removed and deposited on the STM tip. The tip can then move to a predetermined surface site, and the atom or cluster can be redeposited. The magnitude of such forces and the amount of material removed can be controlled by applying voltage pulses at different tip-surface separations.

Magnetic inclusion in the Josephson junction

The fluxon dynamic in the Josephson chains with magnetic inclusions is investigated. In the framework of the McLathlin and Scott perturbation theory it has been shown that fluxons and antifluxons have different interaction energies with magnetic inclusions. The fluxons may be in the bound state with the magnetic inclusion and there is a distance between the centre of fluxon and the magnetic inclusion. The critical current (through the junction) at which the fluxon unbinding takes place is determined. The frequency of the small oscillations of the fluxon in the equilibrium state is calculated. It is shown that there are conditions for the oscillation mode softening. A new type of electronic device is discussed.