Heterojunctions Of Materials Research Articles

High-Performance Gate-Voltage-Tunable Photodiodes Based on Nb2Pd3Se8/WSe2 Mixed-Dimensional Heterojunctions.

The mixed-dimensional (MD) van der Waals (vdWs) heterojunction for photodetectors has garnered significant attention owing to its exceptional compatibility and superior quality. Low-dimensional material heterojunctions exhibit unique photoelectric properties attributed to their nanoscale thickness and vdWs contact surfaces. In this work, a novel MD vdWs heterojunction composed of one-dimensional (1D) Nb2Pd3Se8 nanowires and two-dimensional (2D) WSe2 nanosheets is proposed. The heterojunction's energy band engineering is accomplished by manipulating the Fermi level of the bipolar 2D material via gate voltage, resulting in a rectification characteristic that can be adjusted with gate voltage. Under 685 nm laser irradiation, it demonstrates exceptional self-powered photodetection performance, attaining a photoresponsivity of 1.45 A W-1, an ultrahigh detectivity of 6.8 × 1012 Jones, and an ultrafast response time of 37/64 μs at zero bias. In addition, a broadband photodetector from 255 to 1064 nm is realized. These results demonstrate the great potential of Nb2Pd3Se8/WSe2 MD heterostructures for advanced electronic and optoelectronic devices.

Incorporation of insufficiently vulcanized MoO3 nanocrystals into the hydrothermally grown MoS2/ZnS heterostructures for highly efficient photocatalytic applications

Engineering the multiple heterojunctions of MoS2-based materials provides an important and effective strategy to improve photocatalytic activity. In this work, the insufficiently vulcanized MoO3 intermediates had been incorporated into MoS2/ZnS nanostructured composites using a facile hydrothermal method. The analysis of scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) shows that the multiple heterojunctions were formed among the sphalerite ZnS, molybdenum oxide (MoO3) and MoS2 nanocrystals. Different heterogeneous microstructures among nanosheets, nanoparticles and nanobelts were aggregated through changing the mole fraction of the molybdenum in the mixture precursors. Photocatalytic results confirm that the relatively low ratio of Mo+4/Mo+6 in the ternary composites can significantly improve the catalytic activity for efficiently degrading the organic dye due to the synergistic effect of the multiple heterojunctions. The degradation efficiency achieves 97.9 % of methylene blue (20 mg/L) in 40 min using the photocatalyst dosage of 10 mg. A possible photocatalytic mechanism is also proposed.

Thermodynamic Origin-Based In Situ Electrochemical Construction of Reversible p-n Heterojunctions for Optimal Stability in Potassium Ion Storage.

Heterojunctions in electrode materials offer diverse improvements during the cycling process of energy storage devices, such as volume change buffering, accelerated ion/electron transfer, and better electrode structure integrity, however, obtaining optimal heterostructures with nanoscale domains remains challenging within constrained materials. A novel in situ electrochemical method is introduced to develop a reversible CuSe/PSe p-n heterojunction (CPS-h) from Cu3 PSe4 as starting material, targeting maximum stability in potassium ion storage. The CPS-h formation is thermodynamically favorable, characterized by its superior reversibility, minimized diffusion barriers, and enhanced conversion post K+ interaction. Within CPS-h, the synergy of the intrinsic electric field and P-Se bonds enhance electrode stability, effectively countering the Se shuttling phenomenon. The specific orientation between CuSe and PSe leads to a 35° lattice mismatch generates large space at the interface, promoting efficient K ion migration. The Mott-Schottky analysis validates the consistent reversibility of CPS-h, underlining its electrochemical reliability. Notably, CPS-h demonstrates a negligible 0.005% capacity reduction over 10,000 half-cell cycles and remains stable through 2,000 and 4,000 cycles in full cells and hybrid capacitors, respectively. This study emphasizes the pivotal role of electrochemical dynamics in formulating highly stable p-n heterojunctions, representing a significant advancement in potassium-ion battery (PIB) electrode engineering.

Dynamic Band‐Alignment Modulation in MoTe2/SnSe2 Heterostructure for High Performance Photodetector

AbstractFor two‐dimensional (2D) layered material heterojunctions, dynamic modulation of band alignments allows for the design of devices with flexible multi‐functional applications. In this paper, a device structure is presented based on a MoTe2/SnSe2 field‐effect transistor. By applying a bias voltage to the electrostatic gate, the gate voltage is adjusted from negative to positive, causing the heterojunction to transition from type‐III band alignment to type‐II band alignment. The working mechanism and device performance of the heterojunctions with different band alignments are investigated. The device exhibited outstanding detection range (from ultraviolet to infrared), detectivity (2.42 × 109 Jones), and speed (1.3 ms). Under a positive gate voltage, a higher ratio of light current to dark current (2×103) is achieved. To further demonstrate the potential of the high‐performance devices, their reliability is confirmed through their performance in image recognition using deep learning.

Epitaxial Heterostructures of CsPbBr3 Perovskite Nanocrystals with Post-transition Metal Bismuth.

The facet chemistry of halide perovskite nanocrystals plays a key role in designing nanoscale epitaxial heterostructures. However, despite significant successes achieved in designing these nanocrystals, their heterostructures with several leading transition metals could not be established yet. Herein, the possible heterostructures of metals beyond transition metals are explored and the epitaxial combinations of soft CsPbBr3 nanocrystals with the post-transition metal Bi(0) are reported. These heterostructures are built with interfacing facets having hexagonal atomic configurations of both the rhombicuboctahedron CsPbBr3 and octahedral Bi(0). A high reaction temperature and the presence of alkylamine kept Bi(III) in reduced form and helped in sustaining these CsPbBr3-Bi(0) heteronanocrystals. Since understanding of and synthesis optimization of metal-halide perovskite heterostructures are limited, this finding adds a new fundamental insight in designing ionic and nonionic materials heterojunctions. Furthermore, oxidation and sulfidation of Bi(0) are studied, and the possible oxide/sulfide heterostructures with CsPbBr3 are discussed.

Fabrication of a novel Z-S-scheme photocatalytic fuel cell with the Z-scheme TiO2/GO/g-C3N4 photoanode and S-scheme BiOAc1−xBrx/BiOBr photocathode for TC degradation

The upsurge of interest in the emergence of photocatalytic fuel cell systems (PFC) presents an efficient and environmentally friendly approach to wastewater treatment. In this work, a Z-scheme coupled with an S-scheme heterojunction electrode was used in the PFC, utilizing TiO2/GO/g-C3N4 as the photoanode and BiOAc1–xBrx/BiOBr as the photocathode. We systematically align the band structures between the anode and cathode, which facilitates the electron transfer between the electrodes. Our attempt successfully demonstrates that collaborative power generation facilitates the high efficiency of tetracycline hydrochloride (TC) degradation at both electrodes. The photoanode achieved a 94.87 % degradation rate for TC, while the photocathode exhibited a 96.33 % degradation rate after 2 h, surpassing pristine BiOBr and BiOAc by factors of ∼5.3 and ∼3.8, respectively. Furthermore, this work proposed a mechanism for electron generation, transport, and pollutant degradation mechanism in the PFC. Intermediate substances generated during the degradation of TC were analyzed through high-performance liquid chromatography-mass spectrometry (HPLC-MS) and ultraviolet photoelectron spectroscopy (UPS), while the optimal degradation pathway was confirmed using density functional theory (DFT). The findings of this work establish the feasibility of efficiently degrading pollutants through PFC treatment, introducing a novel system where various heterojunctions in bipolar materials collaborate with photocatalysis to effectively generate electricity and enhance pollutant removal.

Encapsulation of metal particles in porous carbon by microarchitectural design for lightweight and efficient microwave absorption

The construction of heterojunctions in carbon materials is an effective means of preparing absorbers, but still faces challenges in practical applications. In this paper, N-doped porous C/Cu composites with three-dimensional highly conductive structures were prepared from sustainable biomass materials using a microarchitectural design strategy. The results of the study show that the porous structure provides more electromagnetic wave reflection sites on the surface of the material. The doping of N atoms and the embedding of Cu microspheres improve the impedance matching as well as the transmission path of the microcurrents, and the presence of relaxation polarization in the heterojunction at the interface of the carbon matrix and Cu microspheres is of great importance for the enhancement of the microwave absorption properties. The sample has a minimum reflection loss of −60.68 dB and has a maximum effective absorption bandwidth of 5.92 GHz. The CST simulation results verify the outstanding microwave absorption performance of N-doped porous C/Cu composites, with RCS reduction values up to 19.14 dBm2 at a scattering angle of 0 °C. This work provides new insights into the preparation and practical application of high-performance microwave absorbing materials.

Forming of organic/inorganic material heterojunction: Effectively improve the carrier separation rate and solar energy utilization rate

CdS is a kind of traditional inorganic semiconductor, but its photocatalytic performance is far from satisfactory. In order to improve the photocatalytic performance of CdS. We decided to use organic material C2N-h2D to form organic-inorganic heterojunction, CdS/C2N-h2D heterojunction, to improve the photocatalytic performance of CdS. First of all, the CdS, C2N-h2D and CdS/C2N-h2D heterojunction was studied by using the HSE06 hybrid functional method. The energy band and DOS of CdS/C2N-h2D heterojunction were calculated, and the band gap and band types of CdS/C2N-h2D heterojunction were determined. Next, the interaction between CdS and C2N-h2D is discussed. The results showed that the VBM and CBM of CdS and C2N-h2D changed with the forming of heterojunction. In addition, the light absorption spectra show that CdS/C2N-h2D heterojunction has a higher absorption efficiency for visible light. These results indicate that CdS/C2N-h2D heterojunction has a significant advantage in improving the photocatalytic efficiency under visible light irradiation.

Decoration of spherical Sb2S3 over CuO nanoflakes for efficient photoelectrochemical hydrogen generation

Developing an efficient photocathode system from earth abundant materials is essential for effectual Photoelectrochemical (PEC) water splitting. Charge transfer between heterojunctions is important in fabricating a novel photocathode, keeping cost-effectiveness, abundance, and PEC performance in mind. The p-type narrow band gap photocathode, CuO (Eg = 1.5 eV) synthesized by hydrothermal method, was decorated with Sb2S3 Nanospheres (NSs) by adopting a facile chemical bath deposition (CBD) procedure to fabricate CuO/Sb2S3 NSs heterojunction. Fabricated heterojunction showed better PEC performance contrary to bare CuO, improvement in photocurrent density CuO/Sb2S3 NSs (J = −1 mA cm−2) than CuO (J = −0.3 mA cm−2) photoelectrode at 0 VRHE in 0.5 M Na2SO4 (pH 6.85) is due to enhanced charge carrier generation/separation. The photostability of CuO/Sb2S3 remains intact for 2.5 h with no degradation in photocurrent density. Sb2S3 works as a sensitizer, diminishing the recombination rate of the e−/h+ in CuO/Sb2S3 NSs. UV–Visible and photoluminescence(PL) emission spectra results suggested CuO/Sb2S3 enhanced absorption spectrum and reduced rate of recombination. Electrochemical impedance spectroscopy studies show less charge transfer resistance for CuO/Sb2S3 NSs than CuO. This finding will pave new path in developing novel photocathodic material configurations and heterojunction with Cu-based binary oxides/chalcogenides for solar harvesting.

The van der Waals interaction and absorption and electron circular dichroism spectra of two-dimensional bilayer stacked structures

van der Waals (vdW) heterojunctions based on two-dimensional (2D) materials, graphene and transition metal dichalcogenides (TMDs), are a research hotspot for future optoelectronic and exciton devices. Bond-free vdW interactions are key to 2D material heterojunction device reliability and stability. However, most of the current research on 2D stacked materials heterostructures mainly focuses on optical properties and electronic structure. Furthermore, vdW interaction in 2D heterostructures is studied and understood on the basis of qualitative description and energy ranges from the literature. There are few studies on the nature of vdW interaction based on practical calculations of the quantitative strength and microscopic mechanism of vdW interaction between 2D stacked materials. Therefore, this paper explores the vdW interaction between 2D material stacked bilayer structures, including bilayer graphene, graphene/MoS2 and graphene/WS2 heterostructures, focusing on quantitative analysis of the energy components of the vdW interaction. We first visually observed the weak interactions in the three stacked bilayer structures through noncovalent interaction (NCI) analysis, and found that the interactions are concentrated in the binding region between the two-layer structures. We mainly decomposed the weak interaction energy in the three 2D material bilayer heterostructures through energy decomposition analysis based on the force field (EDA-FF) method and obtained the energy values and proportions of the three components-electrostatic energy, exchange repulsion energy and dispersion energy of the total binding energy between the 2D stacked bilayer structures. The vdW interaction energy is the sum of the exchange repulsion energy and dispersion energy, and the dispersion energy of the vdW interaction accounts for more than 60% of the binding energy of the weak interaction between the 2D bilayer stacked structures. The vdW strengths in the bilayer structures are on the order of 177.07, 123.85, and 133.93 kJ/mol, approxmately 1–2 orders of magnitude larger than the classically defined vdW energies of 0.1–10 kJ/mol. Furthermore, we calculate the density of states of the three 2D stacked structures, and further obtained HOMO-LOMO information; to further understand the electronic structures of the graphene/MoS2 and graphene/WS2 heterostructures, we calculated their optical absorption spectra and electron circular dichroism (ECD) spectra. According to the calculation results, the two heterostructures have strong absorption peaks in the visible region, and the charge transfer forms at the strong absorption peak can be determined according to the charge transfer diagram. The ECD spectra indicate that the configurations of the graphene/MoS2 and graphene/WS2 heterostructures have large chirality. Our work contributes to a deeper understanding of the nature of the weak interactions and optical properties in 2D stacked materials, which plays a fundamental role in promoting the construction of stable 2D heterostructure configurations and the development of multifunctional 2D devices. The research is conducive to further promoting the basic research and practical development of strong optoelectronic and excitonic 2D heterojunctions devices.

Boron-doped graphene quantum dot/bismuth molybdate composite photocatalysts for efficient photocatalytic nitrogen fixation reactions

Bismuth molybdate (BMO) is a promising visible-driven photocatalyst and constructing heterojunctions in BMO-based materials is an effective way to enhance photocatalytic performance. In this study, boron-doped graphene quantum dots (BGQDs) were synthesized by one-step pyrolysis and carbonization, followed by the preparation of bismuth molybdate/boron-doped graphene quantum dots (BGQDs/BMO) heterojunction photocatalysts using in-situ growth method. The introduction of BGQDs significantly improved the photocatalytic nitrogen fixation activity under the irradiation of visible light and without scavengers. The highest NH3 yield was achieved with BGQDs/BMO-10, which was 3.48 times higher than pure phase BMO. This improvement was due to the formation of Z-scheme heterojunctions between BGQDs and BMO with the synergistic mechanism of interfacial charge transport and the generation of more protons. This study provides useful guidance for enhancing the visible-light nitrogen fixation performance of BMO materials.

Manipulate the interfacial friction of χ3-borophene on graphene heterojunction via rotation

Manipulating friction between two-dimensional (2D) material heterojunctions is crucial for their application in microscale functional devices. In this study, we have systematically investigated the frictional properties of χ3-Borophene(Bo)/Bo, Bo/Graphene(Gr), and Bo/Gr(30°) by first-principles calculations. The results indicate that the formation of Bo/Gr heterojunctions indeed reduces interfacial sliding potential energy corrugation of Borophene. Interestingly, friction anisotropy appears when commensurate state forms between Gr and Bo along armchair direction of Bo/Gr heterojunction. In addition, this anisotropy vanishes after rotating the heterojunction with an angle of 30°. The Fourier transformation method is applied to illustrate the commensurability of heterojunctions along specific directions. Finally, the interfacial friction behavior is further confirmed to be consistent with the fluctuation of interfacial charge transfer, which emphasizes the atomic stacking and chemical property of heterojunctions.

High-Performance Photodetectors Based on Graphene/MoS₂ Heterojunction FETs

Being an excellent representative of atomically thin 2-D materials, graphene has attracted extensive research attention in the fields of electronic and optoelectronic devices. However, its low-light absorption coefficient, gapless nature, and short carrier lifetime hinder its development in photodetectors. Another atomically thin 2-D semiconducting material molybdenum disulfide (MoS2) has stronger light interaction. Here, we show a high-performance photodetector based on graphene/MoS2 heterojunction field effect transistors (FETs), where the electrodes are fabricated in the middle of two materials. Graphene functions as a conductive material that improves the carrier transmit speed of the device. Meanwhile, MoS2 mainly functions as a light-sensitive material that promotes the generation of photogenerated carriers. The combination of the two materials substantially improves the performance of the photodetector. The photoresponsivity of our device was demonstrated up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1.5} \times {10} ^{{4}}$ </tex-math></inline-formula> A/W under a 470-nm light-emitting diode (LED) light illumination, which was much higher than that of a reported photodetector based on monolayer graphene or MoS2 (~mA/W). Moreover, the photoresponsivity of the device could be easily tuned by applying buried-gate, back-gate, and source–drain voltage, which has important implications for the application of 2-D material photodetectors in neural network image sensor arrays. Our study established a method for large-scale preparation of high-performance photodetector arrays based on 2-D materials heterojunctions.

Research progress of bulk photovoltaic effect in two-dimensional materials

The bulk photovoltaic effect is a second-order nonlinear photoelectric response, which refers to a phenomenon that non-centrosymmetric structural material generates a steady-state photocurrent under uniform light irradiation. The bulk photovoltaic effect has attracted widespread attention due to its open-circuit voltage is not limited by the semiconductor bandgap and power conversion efficiency breaks through the Shockley-Queisser limit. In addition, the bulk photovoltaic effect is closely related to the quantum geometric properties (such as Berry curvature and quantum metric) of solids, thus making it an effective means to study crystal polarization, orbital magnetization, and quantum Hall effects. Two-dimensional (2D) materials are rich in electrical, optical, magnetic, topological properties and their interactions, which can effectively improve the performances of bulk photovoltaic devices (such as expanding response range of bulk photovoltaic effect) and have important research value for exploring basic physical problems. This paper reviews the development process of bulk photovoltaic effect and its physical mechanism. The research progress of bulk photovoltaic effect in 2D materials is discussed in detail, including single component 2D materials, 2D material stacking engineering (such as 2D material homojunctions and heterojunctions), and other factors (such as magnetic field, strain engineering) to generate or regulate the bulk photovoltaic effect response. Finally, the development prospect of two-dimensional bulk photovoltaic effect is prospected.

Dual-mode frequency multiplier in graphene-base hot electron transistor.

Since quantum computers have been gradually introduced in countries around the world, the development of the many related quantum components that can operate independently of temperature has become more important for enabling mature products with low power dissipation and high efficiency. As an alternative to studying cryo-CMOSs (complementary metal-oxide-semiconductors) to achieve this goal, quantum tunneling devices based on 2D materials can be examined instead. In this work, a vertical graphene-based quantum tunneling transistor has been used as a frequency modulator. The transistor can operate via different quantum tunneling mechanisms and generates, by applying the appropriate bias, voltage-resistance curves characteristic of variable nonlinear resistance for both base and emitter voltages. We experimentally demonstrate frequency modulation from input signals over the range of 100 kHz to 10 MHz, enabling a tunable frequency doubler or tripler in just a single transistor. This frequency multiplication with a tunneling mechanism makes the graphene-based tunneling device a promising option for frequency electronics in the emerging field of quantum technologies.

Free-Standing Multilayer MoS2-BP Heterostructures for High Performance Self-Powered Photodetector

Phototransistors based on two-dimensional materials such as graphene, transition metal sulfides, and black phosphorus are widely used in in recent years. However, these materials have weak optical absorption, low carrier mobility or poor air stability, which restrict their application in the field of high-sensitivity detection. The inter-stacking of two-dimensional semiconductors can achieve excellent performance, and has promising applications in the field of optoelectronics. The stacking of two-dimensional semiconductors can form van der Waals heterostructures with low defect states and spatial homogeneity, which is an effective way to improve the performance of 2D photodetectors. Based on this, this paper constructs a free-standing multilayer MoS2-BP heterostructure by mechanical exfoliation for high performance self-powered photodetector. The strong space charge region can effectively separate the photogenerated carriers, so it has a good photodetection capability in the self-driven state. Moreover, we analyse and summarize the working mechanism of photodetectors based on 2D materials, and review high sensitivity detectors of recent years based on 2D material heterojunction. Finally, the challenges to further improve the detection sensitivity are pointed out. Thus, our free-standing multilayer MoS2-BP heterostructure propose a useful experience and reference for the future development of self-power photodetectors.

Novel Ni3S4/NiS/NC composite with multiple heterojunctions synthesized through space-confined effect for high-performance supercapacitors

The construction of heterojunctions in composite materials to optimize the electronic structures and active sites of energy materials is considered to be the promising strategy for the fabrication of high-performance electrochemical energy devices. In this paper, a one-step, easy processing and cost-effective technique for generating composite materials with heterojunctions was successfully developed. The composite containing Ni3S4, NiS, and N-doped amorphous carbon (abbreviated as Ni3S4/NiS/NC) with multiple heterojunction nanosheets are synthesized via the space-confined effect of molten salt interface of recrystallized NaCl. Several lattice matching forms of Ni3S4 with cubic structure and NiS with hexagonal structure are confirmed by the detailed characterization of heterogeneous interfaces. The C–S bonds are the key factor in realizing the chemical coupling between nickel sulfide and NC and constructing the stable heterojunction. Density functional theory calculations further revealed that the electronic interaction on the heterogeneous interface of Ni3S4/NiS can contribute to high electronic conductivity. The heterogeneous interfaces are identified to be the good electroactive region with excellent electrochemical performance. The synergistic effect of abundant active sites, the enhanced kinetic process and valid interface charge transfer channels of Ni3S4/NiS/NC multiple heterojunction can guarantee high reversible redox activity and high structural stability, resulting in both high specific capacitance and energy/power densities when it is used as the electrode for supercapacitors. This work offers a new avenue for the rational design of the heterojunction materials with improved electrochemical performance through space-confined effect of NaCl.

Ultra‐High Speed, High‐Sensitivity Spin‐Cast MXene‐Semiconductor‐MXene Photodetectors

AbstractA simple room‐temperature process of depositing MXene on a III‐V structure with embedded 2D electron gas (2DEG) is used, which results in a large area, , photodetector (PD) device that greatly outperforms vacuum deposited Ti/Au metal‐semiconductor‐metal (MSM) PD's. By co‐optimizing properties of 2D MXene contacts and the III‐V material heterojunctions, this device sets new operating records with responsivity up to 1.04 A W‐1 at low optical powers, corresponding to &gt;230% internal quantum efficiency, dark current of 50 , &gt;105.6‐dB dynamic range, and 25–150 ps response time, which improves the previous MXene‐Semiconductor‐MXene responsivity by &gt;2.7 times and is 7 × 103 –−106 times faster compared to other MXene‐based PDs. This is achieved by enhancing the Schottky barrier height by forming a Van der Waals (vdW) heterojunction between a wide bandgap AlGaAs surface layer and spin coated Ti3C2Tz electrodes. A layered architecture transports the optically generated electrons to a 2DEG channel at the GaAs/AlGaAs heterointerface, where they are rapidly collected. The landscaped electric field pushes the slow holes to an underlying low temperature‐grown GaAs (LT‐GaAs) region where they recombine. The proposed Schottky‐2DEG Photoconductor‐Schottky model for device operation shows how this device circumvents the canonical limitations of gain‐bandwidth product, and carrier transit time, while replacing the need for vacuum deposition of gold or other precious metals.

GeSn based heterojunction double-gate tripple metal layer vertical TFET with enhanced DC and Analog/RF performance

In this article, low-bandgap material GeSn and high bandgap Si material heterojunction (GeSn/Si) based double gate triple metal layer Vertical TFET is designed and analyzed by ATLAS Silvaco TCAD simulation tool. Higher ON-state current is obtained by this device owing to (i) the usage of novel low band-gap material i.e., GeSn and (ii) Vertical tunneling as the gate overlaps the source region. The incorporation of GeSn material not only enhances the ON-state current but also improves the SS, albeit trading off the OFF-state current and ambipolar current of the device. To control the ambipolar current and OFF-state current, variation in the gate to drain overlap and auxiliary gate metal work function has been done. The impact of the gate to drain overlap and auxiliary gate workfunction variation has been studied for various electrical parameters. Further through extensive simulation analysis, optimized dimensions have been obtained. An enormously high ION/IOFF ratio of the order of 1.6 × 1012, steepest point, and average subthreshold swing of 7.5 mV/dec and 12.3 mV/dec respectively has been achieved through this proposed device. In addition to this, comparison of the proposed device with other novel TFET devices reported in literature has been done. From the comparison, it has been concluded that better results are obtained by the proposed device in terms of ION, IAMB, ION/IOFF ratio, SSavg, and gm. Therefore, this novel proposed device can be used as a promising device for various small power applications. Further, this device not only provides improved DC and Analog/RF electrical parameters but also provides small footprint due to vertically aligned architecture.

First principles on the structure and electronic properties of vertically regulated two-dimensional cubic boron nitride and diamond like carbon sandwich heterostructures

Different two-dimensional (2D) materials can be constructed together to achieve complementary advantages and better recognize the functionalization of materials. Dynamic stability analysis indicates that 2D cubic boron nitride (c-BN) and Diamond like carbon (DLC) sandwich heterostructure by (111)-oriented is BN–DLC–BN, vice versa of DLC–BN–DLC is unstable. Following the increase number of DLC layers embedded into BN layers, the structures and band gaps tend to be stable for larger than 6-layer, the value of band gaps still keeps smaller than 1 eV with narrow semiconductors. A low refractive index corresponds to a faster spreading speed than in bulk materials that can be used in optoelectronic sensors. Systematic studies of atomic-level 2D c-BN/DLC sandwich heterostructures following the increase of layer numbers and with distinct surface terminations would anticipated to discover more new types of heterogeneous nano-film, offering an exciting prospect for high-performance 2D material heterojunction devices as future nanoelectronics and nanolasers.