ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• supercapacitor device are important factors in this scenario. Nowadays, ZnO as metal oxide and MXene as 2D materials are the rising stars of electrode materials in supercapacitors due to their highly controllable properties. Therefore, we review the findings about ZnO and MXene in terms of defect structures and

• because of its unique properties, such as ultrathin structure and heterojunction behavior [15]. In the search of other 2D materials, MXenes, which are a novel class of 2D metal carbides, were discovered at Drexel University in 2011 during research in which MAX phases were used as electrode materials in

• potential to be used as an electrode material in supercapacitors. The techniques of structural defect characterization in metal oxides can be applied to 2D materials such as MXenes. We are indeed aiming to transfer the knowledge about semiconductors to 2D materials using the two prototype materials ZnO and

Nanomechanics of few-layer materials: do individual layers slide upon folding?

• Ronaldo J. C. Batista,
• Rafael F. Dias,
• Ana P. M. Barboza,
• Alan B. de Oliveira,
• Taise M. Manhabosco,
• Thiago R. Gomes-Silva,
• Matheus J. S. Matos,
• Andreij C. Gadelha,
• Cassiano Rabelo,
• Luiz G. L. Cançado,
• Ado Jorio,
• Hélio Chacham and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2020, 11, 1801–1808, doi:10.3762/bjnano.11.162

• materials, also called “2D materials”, after exfoliation, eventually creating folded edges across the resulting flakes. We investigate the adhesion and flexural properties of single-layered and multilayered 2D materials upon folding in the present work. This is accomplished by measuring and modeling

• mechanical properties of folded edges, which allows for the experimental determination of the bending stiffness (κ) of multilayered 2D materials as a function of the number of layers (n). In the case of talc, we obtain κ ∝ n3 for n ≥ 5, indicating no interlayer sliding upon folding, at least in this

• interlayer interactions, have been the primary source of 2D materials [1]. These 2D materials exhibit unusual behavior associated regarding their flexural and adhesive properties [2][3][4][5][6][7][8]. For instance, self-assembled folded flaps and nanoribbons of graphene form by spontaneous folding, sliding

Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• local electrical properties of the scanned material are determined without the need of an applied voltage. Some studies reported sMIM measurements performed in doped semiconductors [22] deposited onto FEOL layers, ferroelectrics [23], or 2D materials [22][24]. Here, sMIM was employed to analyse a

Imaging and milling resolution of light ion beams from helium ion microscopy and FIBs driven by liquid metal alloy ion sources

• Nico Klingner,
• Gregor Hlawacek,
• Paul Mazarov,
• Wolfgang Pilz,
• Fabian Meyer and
• Lothar Bischoff

Beilstein J. Nanotechnol. 2020, 11, 1742–1749, doi:10.3762/bjnano.11.156

• formation of helium bubbles in the substrate when using high fluences [5]. In addition to many imaging applications, HIM has been used to create and study new device concepts, including the fabrication of nanometer-sized ferromagnets [6], the controlled tuning of memristive properties of 2D materials [7

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• , we find that irradiating the electrode–channel interface has a deleterious impact on charge transport when contrasted with irradiations confined only to the transistor channel. Keywords: 2D materials; contacts; defect engineering; helium ion microscope; ion beam doping; vacancies; two-dimensional

Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)

• Maximilian Schaal,
• Takumi Aihara,
• Marco Gruenewald,
• Felix Otto,
• Jari Domke,
• Roman Forker,
• Hiroyuki Yoshida and
• Torsten Fritz

Beilstein J. Nanotechnol. 2020, 11, 1168–1177, doi:10.3762/bjnano.11.101

• , Chiba 263-8522, Japan Molecular Chirality Research Center, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan 10.3762/bjnano.11.101 Abstract 2D materials such as hexagonal boron nitride (h-BN) are widely used to decouple organic molecules from metal substrates. Nevertheless, there are

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• decouple such flat-lying molecules from a metal, thin insulating layers have been engineered, ranging from ionic salts [15][16], over oxides [17][18][19], nitrides [20], and molecular layers [21][22] to 2D materials, such as graphene [23][24], and hexagonal boron nitride [25]. The most recent development

Simulations of the 2D self-assembly of tripod-shaped building blocks

• Łukasz Baran,
• Wojciech Rżysko and
• Edyta Słyk

Beilstein J. Nanotechnol. 2020, 11, 884–890, doi:10.3762/bjnano.11.73

• diffraction pattern and average association number. Keywords: 2D materials; coarse-grained model; molecular simulations; self-assembly; structural characterization; tripod building blocks; Introduction On-surface synthesis is a newly developing field in chemistry that aims at making use of solid surfaces as

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

• K. Priya Madhuri,
• Abhay A. Sagade,
• Pralay K. Santra and
• Neena S. John

Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66

• molecules are influenced by the nature of the substrate, which has been attributed to different substrate–molecule interactions [9]. With the application of 2D materials, such as graphene in device configurations, it is important to understand the orientation of MPc molecules on these atomically thin

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• methods also have limitations such as sample damaging or even destruction. Further 2D materials are more likely to be manufactured within existing devices as such following a hybrid approach. Hybrid approaches are the ones mostly pursued; however, they suffer from poor performance due to mismatch

• centers is positively correlated with neutron fluence. This approach suggests that the atomic origin of the color centers emitting at 580 nm is the VB3N1 and it is a viable method to achieve an ensemble of SPEs. SPEs in 2D materials have proved to be resistant to gamma-ray irradiation [128]. We can

Effect of substitutional defects on resonant tunneling diodes based on armchair graphene and boron nitride nanoribbons lateral heterojunctions

• Majid Sanaeepur

Beilstein J. Nanotechnol. 2020, 11, 688–694, doi:10.3762/bjnano.11.56

• heterojunction; armchair boron nitride nanoribbon (ABNNR); armchair graphene nanoribbon (AGNR); negative differential resistance (NDR); nonequilibrium Green’s function (NEGF); resonant tunneling diode (RTD); substitutional defects; Introduction 2D materials have gained tremendous research interest due to the

• electronic devices have been realized by heterostructures based on vertical stacking or lateral stitching of 2D materials with different electronic properties [6]. Lateral graphene/hexagonal boron nitride (Gr/hBN) heterostructures, due to very low lattice mismatch between graphene and hBN, are most suitable

• energies to form a planar 3D structure in which the direction of carrier transport is perpendicular to the interface of stacked materials [21][22][23]. In recent years, a few RTD structures based on 2D materials have been proposed [24][25][26]. In such RTDs the bandgap difference needed for normal

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• , for the particles after irradiation. Compared to the d(001) values of the initial 2D materials, we could not observe any change. Considering the results of 1H NMR in combination with PXRD no significant photoswitching of the azobenzene molecules is detected. Recently published calculations showed that

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• applications. These materials are also interesting as supports for low-dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal

• transition metals, as well as Ag and Au. However, most studies have examined single-atom adsorption or adsorbed nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first-principles

• character of Cu nanoclusters is preserved. Keywords: copper (Cu); density functional theory (DFT); 2D materials; molybdenum disulfide (MoS2); thin film nucleation; Introduction Since the successful exfoliation of monolayers of graphene by Novoselov et al., 2D materials have gained a large interest in a

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• of the relaxation time τ, we apply the deformation potential (DP) theory [25] where τ is estimated by τ = μm*/e. The carrier mobility μ2D in 2D materials is given by Where m* is the effective mass and md is the density of states (DOS) mass determined by E1 is the DP constant and C2D is the elastic

First principles modeling of pure black phosphorus devices under pressure

• Ximing Rong,
• Zhizhou Yu,
• Zewen Wu,
• Junjun Li,
• Bin Wang and
• Yin Wang

Beilstein J. Nanotechnol. 2019, 10, 1943–1951, doi:10.3762/bjnano.10.190

• sensors; WKB approximation; Introduction Black phosphorus (BP) has been regarded as one of the most popular two-dimensional (2D) materials due to their unique properties and potential applications in many fields of nanoelectronics [1][2][3]. So far, many studies have been carried out to explore the

• the use as field-effect transistor [1][25][26][27][28]. Different from the planar 2D materials, such as graphene and silicene, the puckered configuration of BP makes structural deformation much easier by tension or compression along any direction. Meanwhile, large-scale bandgap modulation accompanied

Correction: Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1922–1922, doi:10.3762/bjnano.10.187

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• and Opto-Electronics Engineering, Tianjin University, 92 Weijin road, Tianjin 300072, China 10.3762/bjnano.10.170 Abstract Anisotropic 2D materials exhibit novel optical, electrical and thermoelectric properties that open possibilities for a great variety of angle-dependent devices. Recently

• -response is ascribed to the unique anisotropic in-plane crystal structure, consistent with the optical absorption anisotropy results. In general, 1T’-WTe2, with its highly anisotropic electrical and photoresponsivity reported here, demonstrates a route to exploit the intrinsic anisotropy of 2D materials

• and the possibility to open up new ways for applications of 2D materials for light polarization detection. Keywords: 1T’-WTe2; 2D material; anisotropic; light polarization; optoelectrical; Introduction The first exfoliation of graphene [1] attracted extensive interest in 2D materials such as black

Electronic and magnetic properties of doped black phosphorene with concentration dependence

• Ke Wang,
• Hai Wang,
• Min Zhang,
• Yan Liu and
• Wei Zhao

Beilstein J. Nanotechnol. 2019, 10, 993–1001, doi:10.3762/bjnano.10.100

• graphene has led to extensive research efforts on two-dimensional (2D) materials. Although graphene exhibits large carrier mobility and intriguing mechanical properties, its zero bandgap impedes its application in spintronic devices [1][2]. Subsequently, 2D transition-metal dichalcogenides (TMDs) have

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• materials [4][5][6][7]. Although graphene is the most extensively studied 2D crystal [8], graphene is gapless, and this lack of a bandgap hampers its application in electronic and optoelectronic devices. This has motivated the research on other two-dimensional (2D) materials with a finite bandgap, such as

• performing phonon calculations. These studies were conducted on bulk materials but little is known on the structural and electronic properties of the corresponding isolated layers. By using a datamining procedure some halides were identified as possible 2D materials [14] but their dynamical stability and

• earlier studies [42] that 2D materials can display a much larger sunlight absorption than commonly employed semiconductors. Also, the materials studied here can be employed in heterostructures to complement or replace other large-bandgap 2D materials, such as hexagonal boron nitride, or to dissociate

Trapping polysulfide on two-dimensional molybdenum disulfide for Li–S batteries through phase selection with optimized binding

• Sha Dong,
• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2019, 10, 774–780, doi:10.3762/bjnano.10.77

• [11]. Polar materials were explored to trap LPSs, such as metal oxide [12][13] and metal-carbide nanoparticles [14]. Many two-dimensional (2D) materials, such as borophene [15], silicene [16], phosphorene [17], Mxene [18] and MoS2 [8], have been investigated as anchoring materials due to their large

Choosing a substrate for the ion irradiation of two-dimensional materials

• Egor A. Kolesov

Beilstein J. Nanotechnol. 2019, 10, 531–539, doi:10.3762/bjnano.10.54

• -dimensional materials and as a practical guide on choosing the conditions necessary to obtain certain parameters of irradiated materials. Keywords: 2D materials; defects; hot electrons; ion irradiation; recoils; sputtering; substrate; Introduction Ion irradiation of two-dimensional (2D) materials is a

• irradiation of 2D materials is usually carried out on substrates [1]. However, the substrate choice is known to play a significant (and sometimes crucial) role in the irradiation process [1][2][3][4][5][6][7]. On one hand, it can increase the stability of a monolayer under irradiation, leading to reduction of

• through a simple method of choosing the substrate/ion combination. Due to their nature, 2D materials tend to absorb a small fraction of ion energy in the keV–MeV range [15]. This allows simulations of the bulk substrate effects to be performed independent of the monolayer type. Although not directly

Temperature-dependent Raman spectroscopy and sensor applications of PtSe₂ nanosheets synthesized by wet chemistry

• Mahendra S. Pawar and
• Dattatray J. Late

Beilstein J. Nanotechnol. 2019, 10, 467–474, doi:10.3762/bjnano.10.46

• found to be −0.014 and −0.008, respectively. The nature of the temperature dependence of the Raman spectra of PtSe2 nanosheets is found to be similar in nature to that of graphene and other 2D materials such as MoS2, WS2, MoSe2, WSe2, BP, TiS3, multilayer graphene, and MoTe2 [29][31][32][33][34]. A

• comparison of the temperature coefficient values corresponding to various 2D materials are shown in Table 2. The value of Δω for both Eg and A1g modes was found to be 6.11 cm−1 and 3.14 cm−1, respectively. Humidity sensor and photodetector based on few-layer PtSe2 nanosheets Figure 7a shows the typical

• conductivity of the sensor device, similar to that observed for other 2D materials such as SnSe2 [35], MoS2 [36], BP [26], and MoSe2 [37]. Figure 7b shows a typical current–time (I–t) plot where cycles of 11.3% and 97.3% RH levels were used to calculate the response and recovery time. The response and recovery

Contactless photomagnetoelectric investigations of 2D semiconductors

• Marian Nowak,
• Marcin Jesionek,
• Barbara Solecka,
• Piotr Szperlich,
• Piotr Duka and
• Anna Starczewska

Beilstein J. Nanotechnol. 2018, 9, 2741–2749, doi:10.3762/bjnano.9.256

• diffusion length of carriers in different 2D materials. Keywords: carrier mobility; contactless investigations; graphene; photomagnetoelectric effect; 2D materials; Introduction The application of two-dimensional (2D) materials in electronic devices [1][2][3][4][5][6] requires the development of

• concentration (μe = 1256(25) cm2V−1s−1 and ne = 4.65(6)·1016 m−2 determined using Van der Pauw method). It should be underlined that one of the most important properties of graphene [33][34][35] and other 2D materials [2][36][37][38][39][40][41] is the strong electric field effect which leads to

• investigations should be performed on the same material using PME as well as other methods of determining carrier mobility. Conclusion The investigation of complex phenomena in 2D materials requires the combination of multiple experimental techniques. The contactless PME method, used in Corbino geometry, is

Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared

• Pavel Loiko,
• Tanujjal Bora,
• Josep Maria Serres,
• Haohai Yu,
• Magdalena Aguiló,
• Francesc Díaz,
• Uwe Griebner,
• Valentin Petrov,
• Xavier Mateos and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2018, 9, 2730–2740, doi:10.3762/bjnano.9.255

• related to higher scattering losses in such SAs at ≈1 µm, as well as higher saturation intensities of such materials for higher photon energies. ZnO NRs are slightly better than such 2D materials as graphene-SA with a single carbon layer and few-layer MoS2. However, their performance is inferior as

• compared to the SWCNT-SAs, while the latter are less attractive since they are deposited in the form of a polymer thin film. For the Tm laser, the best output characteristics are again achieved with the SWCNT-SA. The PQS performance of the ZnO NRs is better than other 2D materials (graphene-SA with a

• lower than for 2D materials such as graphene and MoS2. The modulation depth of ZnO NRs can be easily adjusted by the growth duration. The application of ZnO NRs as SAs in bulk Yb and Tm lasers indicated their capability to generate nanosecond pulses at high repetition rates up to the MHz-range with µJ

Two-dimensional semiconductors pave the way towards dopant-based quantum computing

• José Carlos Abadillo-Uriel,
• Belita Koiller and
• María José Calderón

Beilstein J. Nanotechnol. 2018, 9, 2668–2673, doi:10.3762/bjnano.9.249

• not occur when the conduction-band edge is at k = 0. We investigate the possibility of circumventing this problem by using two-dimensional (2D) materials as hosts. Dopants in 2D systems are more tightly bound and potentially easier to position and manipulate. Moreover, many of them present the

• (for two-qubit operations). Our results indicate that a wide variety of 2D materials may perform at least as well as, and possibly better, than the currently studied bulk host materials for donor qubits. Keywords: two-dimensional (2D) materials; dopants; qubits; quantum computing; Introduction

• bulk, because it only requires control over two coordinates, avoiding the z-component uncertainties, see Figure 1. More importantly, quite a few 2D materials present the conduction band minimum at the Γ point [19][20], naturally reducing the required donor positioning accuracy, as no oscillatory