Submit to Special Issue Submit Abstract to Special Issue Review for Nanomaterials Propose a Special Issue

Journal Menu

Journal Browser

2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Nanoelectronics, Nanosensors and Devices".

Deadline for manuscript submissions: 30 December 2024 | Viewed by 14406

Share This Special Issue

Special Issue Editors

Dr. Filippo Giannazzo

E-Mail Website
Guest Editor

Consiglio Nazionale delle Ricerche–Institute for Microelectronics and Microsystems (CNR-IMM), Strada VIII, I-95121 Catania, Italy
Interests: 2D materials (graphene, transition metal dichalcogenides); wide-bandgap semiconductors (SiC, GaN); high-power and high-frequency electronics; electrical atomic force microscopy (C-AFM, SCM, SSRM)
Special Issues, Collections and Topics in MDPI journals

Dr. Federica Bondino

E-Mail Website
Guest Editor

CNR-IOM, I-34149 Trieste, Italy
Interests: synthesis and characterization of low-dimensional materials (graphene, nanoribbons, nanographene, transition metal dichalcogenides); reactivity at interfaces and surfaces; on-surface processes; XPS

Dr. Luca Seravalli

E-Mail Website
Guest Editor

CNR-IMEM Institute, Parco delle Scienze 37a, I-43100 Parma, Italy
Interests: CVD growth of transition-metal dichalcogenides; MOVPE growth and characterization of wide-band semiconductor oxides (Ga₂O₃); MOVPE growth, characterization and modelling of semiconductor nanowires for application in sensing
Special Issues, Collections and Topics in MDPI journals

Dr. Simonpietro Agnello

E-Mail Website
Guest Editor

Dipartimento di Fisica e Chimica—Emilio Segrè, Università degli Studi di Palermo, Via Archirafi 36, 90123 Palermo, Italy
Interests: 2D materials; optical; Raman and electron paramagnetic resonance spectroscopy studies of advanced materials for optics, electronics and photonics; irradiation effects on matter
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

2D layered materials (including graphene, transition metal dichalcogenides and hexagonal boron nitride) and their van der Waals heterostructures have beeen the object of intensive investigations for their potential applications in electronics/optoelectronics, sensing, quantum and energy applications. In particular, the integration of 2D materials with bulk (3D) semiconductors, such as Si, Ge and wide-bandgap semiconductors (SiC, GaN), is currently being explored to combine their functional properties with mature microelectronics technology, thus allowing for the demonstration of advanced or radically new device concepts.

The present Special Issue aims to collect significant contributions on the scalable growth of 2D materials and on the fabrication approaches of 2D materials heterostructures. Advanced characterization methods (optical, vibrational, chemical, electrical) and theoretical modelling of these heterostructures will be in the scope of this collection. Furthermore, we will host papers addressing the challenges involved in 2D material integration and device fabrication, as well as those that demonstrate novel applications in electronics/optoelectronics and sensing.

It is our pleasure to invite you to submit a manuscript for this Special Issue. Full papers, short communications and reviews are welcome.

Dr. Filippo Giannazzo
Dr. Federica Bondino
Dr. Luca Seravalli
Dr. Simonpietro Agnello
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

2D materials such as graphene, transition metal dichalcogenides, h-BN, Xenes (silicene, stanene, phosphorene, etc.), MXenes
Van der Waals heterostructures
large area growth methods of 2D materials (CVD, MOCVD, MBE, PLD, ALD)
advanced characterizations of 2D materials and heterostructures (AFM, TEM, Raman, optical and photoelectron spectroscopy)
theoretical modelling
electronic/optoelectronics applications (digital, RF, photodetectors, flexible/wearable electronics)
sensors (environmental, chemical, biomedical applications)
quantum technologies
energy technologies (light harvesting, thermoelectrics, batteries/supercapacitors, hydrogen evolution reaction)

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (10 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

14 pages, 2959 KiB

Open AccessArticle

Influence of the Carrier Gas Flow in the CVD Synthesis of 2-Dimensional MoS₂ Based on the Spin-Coating of Liquid Molybdenum Precursors

by Fiorenza Esposito, Matteo Bosi, Giovanni Attolini, Francesca Rossi, Roberto Fornari, Filippo Fabbri and Luca Seravalli

Nanomaterials 2024, 14(21), 1749; https://doi.org/10.3390/nano14211749 - 31 Oct 2024

Viewed by 687

Abstract

Atomically thin molybdenum disulfide (MoS₂) is a two-dimensional semiconductor with versatile applications. The recent adoption of liquid molybdenum precursors in chemical vapor deposition has contributed significantly to the reproducible wafer-scale synthesis of MoS₂ monolayer and few-layer films. In this work, we study the effects of the carrier gas flow rate on the properties of two-dimensional molybdenum disulfide grown by liquid-precursor-intermediate chemical vapor deposition on SiO₂/Si substrates. We characterized the samples using Optical Microscopy, Scanning Electron Microscopy, Raman spectroscopy, and Photoluminescence spectroscopy. We analyzed samples grown with different nitrogen carrier flows, ranging from 150 to 300 sccm, and discussed the effect of carrier gas flows on their properties. We found a correlation between MoS₂ flake lateral size, shape, and number of layers, and we present a qualitative growth model based on changes in sulfur provision caused by different carrier flows. We show how the use of liquid precursors can allow for the synthesis of homogeneous, single-layer flakes up to 100 µm in lateral size by optimizing the gas flow rate. These results are essential for gaining a deeper understanding of the growth process of MoS₂. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

17 pages, 39089 KiB

Open AccessArticle

Electronic and Optical Properties of 2D Heterostructure Bilayers of Graphene, Borophene and 2D Boron Carbides from First Principles

by Lu Niu, Oliver J. Conquest, Carla Verdi and Catherine Stampfl

Nanomaterials 2024, 14(20), 1659; https://doi.org/10.3390/nano14201659 - 16 Oct 2024

Viewed by 787

Abstract

In the present work the atomic, electronic and optical properties of two-dimensional graphene, borophene, and boron carbide heterojunction bilayer systems (Graphene–BC₃, Graphene–Borophene and Graphene–B₄C₃) as well as their constituent monolayers are investigated on the basis of first-principles calculations using the HSE06 hybrid functional. Our calculations show that while borophene is metallic, both monolayer BC₃ and B₄C₃ are indirect semiconductors, with band-gaps of 1.822 eV and 2.381 eV as obtained using HSE06. The Graphene–BC₃ and Graphene–B₄C₃ bilayer heterojunction systems maintain the Dirac point-like character of graphene at the K-point with the opening of a very small gap (20–50 meV) and are essentially semi-metals, while Graphene–Borophene is metallic. All bilayer heterostructure systems possess absorbance in the visible region where the resonance frequency and resonance absorption peak intensity vary between structures. Remarkably, all heterojunctions support plasmons within the range 16.5–18.5 eV, while Graphene–B₄C₃ and Graphene–Borophene exhibit a

π

-type plasmon within the region 4–6 eV, with the latter possessing an additional plasmon at the lower energy of 1.5–3 eV. The dielectric tensor for Graphene–B₄C₃ exhibits complex off-diagonal elements due to the lower P3 space group symmetry indicating it has anisotropic dielectric properties and could exhibit optically active (chiral) effects. Our study shows that the two-dimensional heterostructures have desirable optical properties broadening the potential applications of the constituent monolayers. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

15 pages, 2843 KiB

Open AccessEditor’s ChoiceArticle

p-Type Schottky Contacts for Graphene Adjustable-Barrier Phototransistors

by Carsten Strobel, Carlos Alvarado Chavarin, Martin Knaut, Matthias Albert, André Heinzig, Likhith Gummadi, Christian Wenger and Thomas Mikolajick

Nanomaterials 2024, 14(13), 1140; https://doi.org/10.3390/nano14131140 - 2 Jul 2024

Viewed by 1189

Abstract

The graphene adjustable-barriers phototransistor is an attractive novel device for potential high speed and high responsivity dual-band photodetection. In this device, graphene is embedded between the semiconductors silicon and germanium. Both n-type and p-type Schottky contacts between graphene and the semiconductors are required for this device. While n-type Schottky contacts are widely investigated, reports about p-type Schottky contacts between graphene and the two involved semiconductors are scarce. In this study, we demonstrate a p-type Schottky contact between graphene and p-germanium. A clear rectification with on–off ratios of close to 10³ (±5 V) and a distinct photoresponse at telecommunication wavelengths in the infrared are achieved. Further, p-type silicon is transferred to or deposited on graphene, and we also observe rectification and photoresponse in the visible range for some of these p-type Schottky junctions. These results are an important step toward the realization of functional graphene adjustable-barrier phototransistors. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Graphical abstract

9 pages, 3951 KiB

Open AccessArticle

Fabrication and Enhanced Performance Evaluation of TiO₂@Zn/Al-LDH for DSSC Application: The Influence of Post-Processing Temperature

by Altaf Hussain Rajpar, Mohamed Bashir Ali Bashir, Ethar Yahya Salih and Emad M. Ahmed

Nanomaterials 2024, 14(11), 920; https://doi.org/10.3390/nano14110920 - 24 May 2024

Viewed by 919

Abstract

A sequence of dye-sensitized solar cells is proposed, utilizing TiO₂@Zn/Al-layered double hydroxide (LDH) as their starting materials, in which Ruthenizer N719 was used as a photon absorber. The anticipated system was turned into sheet-like TiO₂@mixed metal oxide (MMO) via post-processing treatment. The crystal quality indicated a relation to power conversion efficiency (PCE); this was combined with a comparable morphology profile. In detail, the optimum DSSC device exhibited average sheet-like thickness and a dye loading amount of 43.11 nm and 4.28

\times 10^{- 3}

mM/cm⁻², respectively. Concurrently, a considerable PCE enhancement of the optimum DSSC device (TiO₂@MMO-550°) was attained compared to pristine MMO (0.91%), which could be due to boosted electron transfer efficiency. Of the fabricated devices, DSSC fabricated at 550° exhibited the highest PCE (1.91%), with a 35.6% enhancement compared to that obtained at 450°, as a result of its increased open-circuit voltage (3.29 mA/cm²) and short-circuit current (0.81 V). The proposed work delivers an enhanced efficiency as compared to similar geometries. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

7 pages, 2953 KiB

Open AccessCommunication

AC Characteristics of van der Waals Bipolar Junction Transistors Using an MoS₂/WSe₂/MoS₂ Heterostructure

by Zezhang Yan, Ningsheng Xu and Shaozhi Deng

Nanomaterials 2024, 14(10), 851; https://doi.org/10.3390/nano14100851 - 14 May 2024

Viewed by 1205

Abstract

Two-dimensional layered materials, characterized by their atomically thin thicknesses and surfaces that are free of dangling bonds, hold great promise for fabricating ultrathin, lightweight, and flexible bipolar junction transistors (BJTs). In this paper, a van der Waals (vdW) BJT was fabricated by vertically stacking MoS₂, WSe₂, and MoS₂ flakes in sequence. The AC characteristics of the vdW BJT were studied for the first time, in which a maximum common emitter voltage gain of around 3.5 was observed. By investigating the time domain characteristics of the device under various operating frequencies, the frequency response of the device was summarized, which experimentally proved that the MoS₂/WSe₂/MoS₂ BJT has voltage amplification capability in the 0–200 Hz region. In addition, the phase response of the device was also investigated. A phase inversion was observed in the low-frequency range. As the operating frequency increases, the relative phase between the input and output signals gradually shifts until it is in phase at frequencies exceeding 2.3 kHz. This work demonstrates the signal amplification applications of the vdW BJTs for neuromorphic computing and wearable healthcare devices. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

11 pages, 3048 KiB

Open AccessArticle

Self-Powered Broadband Photodetector Based on NiO/Si Heterojunction Incorporating Graphene Transparent Conducting Layer

by Bhishma Pandit, Bhaskar Parida, Hyeon-Sik Jang and Keun Heo

Nanomaterials 2024, 14(6), 551; https://doi.org/10.3390/nano14060551 - 21 Mar 2024

Cited by 2 | Viewed by 1501

Abstract

In this study, a self-powered broadband photodetector based on graphene/NiO/n-Si was fabricated by the direct spin-coating of nanostructured NiO on the Si substrate. The current–voltage measurement of the NiO/Si heterostructure exhibited rectifying characteristics with enhanced photocurrent under light illumination. Photodetection capability was measured in the range from 300 nm to 800 nm, and a higher photoresponse in the UV region was observed due to the wide bandgap of NiO. The presence of a top graphene transparent conducting electrode further enhanced the responsivity in the whole measured wavelength region from 350 to 800 nm. The photoresponse of the NiO/Si detector at 350 nm was found to increase from 0.0187 to 0.163 A/W at −1 V with the insertion of the graphene top layer. A high photo-to-dark current ratio (≃10⁴) at the zero bias indicates that the device has advantageous application in energy-efficient high-performance broadband photodetectors. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

14 pages, 3105 KiB

Open AccessArticle

Multi-Layer Palladium Diselenide as a Contact Material for Two-Dimensional Tungsten Diselenide Field-Effect Transistors

by Gennadiy Murastov, Muhammad Awais Aslam, Simon Leitner, Vadym Tkachuk, Iva Plutnarová, Egon Pavlica, Raul D. Rodriguez, Zdenek Sofer and Aleksandar Matković

Nanomaterials 2024, 14(5), 481; https://doi.org/10.3390/nano14050481 - 6 Mar 2024

Cited by 1 | Viewed by 2276

Abstract

Tungsten diselenide (

{WSe}_{2}

) has emerged as a promising ambipolar semiconductor material for field-effect transistors (FETs) due to its unique electronic properties, including a sizeable band gap, high carrier mobility, and remarkable on–off ratio. However, engineering the contacts to

{WSe}_{2}

[...] Read more.

Tungsten diselenide (

{WSe}_{2}

{WSe}_{2}

remains an issue, and high contact barriers prevent the utilization of the full performance in electronic applications. Furthermore, it could be possible to tune the contacts to

{WSe}_{2}

for effective electron or hole injection and consequently pin the threshold voltage to either conduction or valence band. This would be the way to achieve complementary metal–oxide–semiconductor devices without doping of the channel material.This study investigates the behaviour of two-dimensional

{WSe}_{2}

field-effect transistors with multi-layer palladium diselenide (

{PdSe}_{2}

) as a contact material. We demonstrate that

{PdSe}_{2}

contacts favour hole injection while preserving the ambipolar nature of the channel material. This consequently yields high-performance p-type

{WSe}_{2}

devices with

{PdSe}_{2}

van der Waals contacts. Further, we explore the tunability of the contact interface by selective laser alteration of the

{WSe}_{2}

under the contacts, enabling pinning of the threshold voltage to the valence band of

{WSe}_{2}

, yielding pure p-type operation of the devices. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

14 pages, 3152 KiB

Open AccessArticle

Asymmetric Schottky Barrier-Generated MoS₂/WTe₂ FET Biosensor Based on a Rectified Signal

by Xinhao Zhang, Shuo Chen, Heqi Ma, Tianyu Sun, Xiangyong Cui, Panpan Huo, Baoyuan Man and Cheng Yang

Nanomaterials 2024, 14(2), 226; https://doi.org/10.3390/nano14020226 - 20 Jan 2024

Cited by 3 | Viewed by 1831

Abstract

Field-effect transistor (FET) biosensors can be used to measure the charge information carried by biomolecules. However, insurmountable hysteresis in the long-term and large-range transfer characteristic curve exists and affects the measurements. Noise signal, caused by the interference coefficient of external factors, may destroy the quantitative analysis of trace targets in complex biological systems. In this report, a “rectified signal” in the output characteristic curve, instead of the “absolute value signal” in the transfer characteristic curve, is obtained and analyzed to solve these problems. The proposed asymmetric Schottky barrier-generated MoS₂/WTe₂ FET biosensor achieved a 10⁵ rectified signal, sufficient reliability and stability (maintained for 60 days), ultra-sensitive detection (10 aM) of the Down syndrome-related DYRK1A gene, and excellent specificity in base recognition. This biosensor with a response range of 10 aM–100 pM has significant application potential in the screening and rapid diagnosis of Down syndrome. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

9 pages, 3493 KiB

Open AccessCommunication

Symmetry-Engineering-Induced In-Plane Polarization Enhancement in Ta₂NiS₅/CrOCl van der Waals Heterostructure

by Yue Su, Peng Chen, Xiangrui Xu, Yufeng Zhang, Weiwei Cai, Gang Peng, Xueao Zhang and Chuyun Deng

Nanomaterials 2023, 13(23), 3050; https://doi.org/10.3390/nano13233050 - 29 Nov 2023

Viewed by 1301

Abstract

Van der Waals (vdW) interfaces can be formed via layer stacking regardless of the lattice constant or symmetry of the individual building blocks. Herein, we constructed a vdW interface of layered Ta₂NiS₅ and CrOCl, which exhibited remarkably enhanced in-plane anisotropy via polarized Raman spectroscopy and electrical transport measurements. Compared with pristine Ta₂NiS₅, the anisotropy ratio of the Raman intensities for the B_2g, ²A_g, and ³A_g modes increased in the heterostructure. More importantly, the anisotropy ratios of conductivity and mobility in the heterostructure increased by one order of magnitude. Specifically speaking, the conductivity ratio changed from ~2.1 (Ta₂NiS₅) to ~15 (Ta₂NiS₅/CrOCl), while the mobility ratio changed from ~2.7 (Ta₂NiS₅) to ~32 (Ta₂NiS₅/CrOCl). Such prominent enhancement may be attributed to the symmetry reduction caused by lattice mismatch at the heterostructure interface and the introduction of strain into the Ta₂NiS₅. Our research provides a new perspective for enhancing artificial anisotropy physics and offers feasible guidance for future functionalized electronic devices. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Figure 1

13 pages, 6187 KiB

Open AccessArticle

Large-Area MoS₂ Films Grown on Sapphire and GaN Substrates by Pulsed Laser Deposition

by Marianna Španková, Štefan Chromik, Edmund Dobročka, Lenka Pribusová Slušná, Marcel Talacko, Maroš Gregor, Béla Pécz, Antal Koos, Giuseppe Greco, Salvatore Ethan Panasci, Patrick Fiorenza, Fabrizio Roccaforte, Yvon Cordier, Eric Frayssinet and Filippo Giannazzo

Nanomaterials 2023, 13(21), 2837; https://doi.org/10.3390/nano13212837 - 26 Oct 2023

Cited by 3 | Viewed by 1666

Abstract

In this paper, we present the preparation of few-layer MoS₂ films on single-crystal sapphire, as well as on heteroepitaxial GaN templates on sapphire substrates, using the pulsed laser deposition (PLD) technique. Detailed structural and chemical characterization of the films were performed using Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction measurements, and high-resolution transmission electron microscopy. According to X-ray diffraction studies, the films exhibit epitaxial growth, indicating a good in-plane alignment. Furthermore, the films demonstrate uniform thickness on large areas, as confirmed by Raman spectroscopy. The lateral electrical current transport of the MoS₂ grown on sapphire was investigated by temperature (T)-dependent sheet resistance and Hall effect measurements, showing a high n-type doping of the semiconducting films (n_s from ~1 × 10¹³ to ~3.4 × 10¹³ cm⁻² from T = 300 K to 500 K), with a donor ionization energy of E_i = 93 ± 8 meV and a mobility decreasing with T. Finally, the vertical current injection across the MoS₂/GaN heterojunction was investigated by means of conductive atomic force microscopy, showing the rectifying behavior of the I-V characteristics with a Schottky barrier height of ϕ_B ≈ 0.36 eV. The obtained results pave the way for the scalable application of PLD-grown MoS₂ on GaN in electronics/optoelectronics. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

► Show Figures

Journal Menu

Journal Browser

2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (10 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI