Recent progress on field-effect transistor-based biosensors: device perspective

• Billel Smaani,
• Fares Nafa,
• Mohamed Salah Benlatrech,
• Ismahan Mahdi,
• Hamza Akroum,
• Mohamed walid Azizi,
• Khaled Harrar and
• Sayan Kanungo

Beilstein J. Nanotechnol. 2024, 15, 977–994, doi:10.3762/bjnano.15.80

• of the electrode gate (with metal 2) is interfaced with HfO2 high-k dielectric with the body channel. The source region is P+ doped but the drain region is N+ doped, as shown in Figure 17. In this context, a low bandgap material (InAs) was implemented in the source region to achieve better band-to

• to other TFET-based biosensor topologies [126][127] and conventional FET-based biosensors [128] by utilizing a gate-engineered heterostructure and low bandgap materials in the source region, which facilitates efficient carrier band-to-band tunneling. Furthermore, extended gate architecture is

Intermixing of MoS₂ and WS₂ photocatalysts toward methylene blue photodegradation

• Maryam Al Qaydi,
• Nitul S. Rajput,
• Michael Lejeune,
• Abdellatif Bouchalkha,
• Mimoun El Marssi,
• Steevy Cordette,
• Chaouki Kasmi and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2024, 15, 817–829, doi:10.3762/bjnano.15.68

• ]. Typically, semiconductor-based photocatalysts, such as TiO2, ZnO2, and some other high-bandgap transition-metal dichalcogenides (TMD) have shown their ability to efficiently degrade the activated MB by irradiation [10][11]. Recently, TMD such as MoS2 and WS2, have displayed remarkable potential as

• adsorbed onto the surface of the catalyst [20], then the illumination with energy greater than that of the bandgap will promote electrons (e−) to the conduction band (CB), leaving holes (h+) in the valence band (VB). Simultaneously, oxygen molecules on the surface of the catalyst capture the excited

• materials while taking into account their bandgap energies, as per the following equations: where ECB is the energy level of the conduction band, EVB is the energy level of the valence band, Eg(x) and X(x) are the bandgap and the electronegativity of the respective material. E0 represents the scaling

Effect of repeating hydrothermal growth processes and rapid thermal annealing on CuO thin film properties

• Monika Ozga,
• Eunika Zielony,
• Aleksandra Wierzbicka,
• Anna Wolska,
• Marcin Klepka,
• Marek Godlewski,
• Bogdan J. Kowalski and
• Bartłomiej S. Witkowski

Beilstein J. Nanotechnol. 2024, 15, 743–754, doi:10.3762/bjnano.15.62

• devices. Keywords: CuO; hydrothermal method; rapid thermal annealing; thin films; Introduction Copper(II) oxide is a p-type semiconductor possessing a narrow bandgap, along with many beneficial electrical, optical, and magnetic properties. Particularly at the nanoscale, these properties set themselves

Simultaneous electrochemical determination of uric acid and hypoxanthine at a TiO₂/graphene quantum dot-modified electrode

• Vu Ngoc Hoang,
• Dang Thi Ngoc Hoa,
• Nguyen Quang Man,
• Le Vu Truong Son,
• Le Van Thanh Son,
• Vo Thang Nguyen,
• Le Thi Hong Phong,
• Ly Hoang Diem,
• Kieu Chan Ly,
• Ho Sy Thang and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 719–732, doi:10.3762/bjnano.15.60

• properties. Graphene quantum dots (GQDs) are zero-dimensional graphene derivatives consisting of one to few layers of graphene sheets with a size of less than 20 nm in width [11]. The missing bandgap results in an absence of luminescence in pristine graphene. However, a bandgap can be generated in GQDs

Reduced subthreshold swing in a vertical tunnel FET using a low-work-function live metal strip and a low-k material at the drain

• Kalai Selvi Kanagarajan and
• Dhanalakshmi Krishnan Sadhasivan

Beilstein J. Nanotechnol. 2024, 15, 713–718, doi:10.3762/bjnano.15.59

• characteristics grow when Cgd rises [8]. The gate-to-drain capacitance increases as a result of a high-k material in the drain region [9]. Ambipolar leakage and Miller capacitance are two drawbacks of TFETs. The Miller capacitance can be reduced through oxide overlap and low-bandgap materials [10]. The solution

• to reduce gate oxide leakage are high-k materials. The device’s ability to keep a charge is increased by using high-k materials, which also aids in downsizing. HfO2 is compatible with a silicon substrate and possesses a high dielectric constant (ε ≈ 25), a large bandgap (5.68 eV), band offsets with

• compared to the VTFET in [12] to demonstrate the effects of the low-work-function live strip and the low-k material. The device parameters used are listed in Table 1. Reference [12] used bandgap narrowing, Shockley–Read–Hall recombination, Lombardi's mobility model, and band-to-band (non-local) modeling

Elastic modulus of β-Ga₂O₃ nanowires measured by resonance and three-point bending techniques

• Annamarija Trausa,
• Sven Oras,
• Sergei Vlassov,
• Mikk Antsov,
• Tauno Tiirats,
• Andreas Kyritsakis,
• Boris Polyakov and
• Edgars Butanovs

Beilstein J. Nanotechnol. 2024, 15, 704–712, doi:10.3762/bjnano.15.58

• , University of Tartu, Nooruse 1, 50411 Tartu, Estonia Estonian Military Academy, Riia 12, 51010 Tartu, Estonia 10.3762/bjnano.15.58 Abstract Due to the recent interest in ultrawide bandgap β-Ga2O3 thin films and nanostructures for various electronics and UV device applications, it is important to understand

Aero-ZnS prepared by physical vapor transport on three-dimensional networks of sacrificial ZnO microtetrapods

• Veaceslav Ursaki,
• Tudor Braniste,
• Victor Zalamai,
• Emil Rusu,
• Vladimir Ciobanu,
• Vadim Morari,
• Daniel Podgornii,
• Pier Carlo Ricci,
• Rainer Adelung and
• Ion Tiginyanu

Beilstein J. Nanotechnol. 2024, 15, 490–499, doi:10.3762/bjnano.15.44

• a phase with hexagonal wurtzite structure. The good crystalline quality of the ZnS component of the aeromaterial was revealed by the XRD analysis. In order to assess the optical quality, PL spectra were analyzed under resonant near-bandgap and intraband excitation. The PL spectra of samples prepared

• the bandgap of the wurtzite ZnS phase is larger than that of the zinc blende phase. The behavior of these PL bands is also different in the two samples when changing the environment, as deduced from Figure 5. The intensity of the PL bands in the sample prepared in the 4 h procedure is not

• measured at low temperature in the near-bandgap region, as shown in Figure 6. Apart from that, a narrow emission peak is observed at 3.726 eV. This peak is assigned to multiphonon resonant Raman scattering (RRS) in ZnS since the quantum energy difference between the excitation laser line (3.814 eV) and the

Photocatalytic degradation of methylene blue under visible light by cobalt ferrite nanoparticles/graphene quantum dots

• Vo Chau Ngoc Anh,
• Le Thi Thanh Nhi,
• Le Thi Kim Dung,
• Dang Thi Ngoc Hoa,
• Nguyen Truong Son,
• Nguyen Thi Thao Uyen,
• Nguyen Ngoc Uyen Thu,
• Le Van Thanh Son,
• Le Trung Hieu,
• Tran Ngoc Tuyen and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 475–489, doi:10.3762/bjnano.15.43

• that the resulting composite can enhance the absorption capacity [11]. This observation is an agreement with previous works [11]. In addition, a slight shift of the PL emission peak is also observed because of the blue shift in the UV–vis spectrum, which is consistent with their bigger bandgap energy

Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• fascinating optical and electrical properties [1]. WOx is a wide-bandgap oxide semiconductor with a large excitonic binding energy of 0.15 eV and a high optical absorption coefficient (≥104 cm−1 in the UV region) [2]. These, in conjunction with decent carrier mobility (12 cm2·V−1·s−1), make this material an

• , bandgap, and electrical conductivity, to a large extent by controlling the cationic oxidation state and the film stoichiometry [2]. As a matter of fact, adjustments in the film stoichiometry and microstructure are experimentally viable by the choice of a suitable growth technique [9][10][11]. As a result

• optical bandgap and work function is thoroughly investigated by employing various spectroscopic and microscopic techniques. The systematic investigation of the work function of the films reveals a distinct trend with thickness, originating from the thickness-dependent defect concentration within the films

Investigating structural and electronic properties of neutral zinc clusters: a G₀W₀ and G₀W₀Г₀⁽¹⁾ benchmark

• Sunila Bakhsh,
• Muhammad Khalid,
• Sameen Aslam,
• Muhammad Sohail,
• Muhammad Aamir Iqbal,
• Mujtaba Ikram and
• Kareem Morsy

Beilstein J. Nanotechnol. 2024, 15, 310–316, doi:10.3762/bjnano.15.28

• trend, which follows the behavior of metallic bandgaps. One exception is the zinc dimer, for which our bandgap from calculations is relatively high, which may be attributed to the van der Waals forces. The HOMO–LUMO gap trend shows that, at larger sizes, the behavior of the cluster becomes close to

• that of the bulk material, that is, the HOMO–LUMO gap decreases. As seen in Figure 4, the bandgap values obtained from GW calculations are far from the bulk limit of metals. In our work, the HOMO–LUMO gap decreases from ca. 8.5 eV to approximately 3.5 eV, but it is still sizable compared with the bulk

• metal energy gap. Apart from this situation, for small-size clusters or nanoparticles, it is possible to observe quantum confinement effects resulting in an indeterminate bandgap, such as in the case of semiconductor clusters. As the size of the cluster decreases, the electronic energy levels become

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• transition to a direct bandgap semiconductor with very high photoluminescence quantum yield when thinned down to a monolayer [13][14][15][16][17]. Its unique electronic and optical properties could provide an edge in many future applications. The multilayers MoS2 structures are of the most common 2Hc type

A visible-light photodetector based on heterojunctions between CuO nanoparticles and ZnO nanorods

• Doan Nhat Giang,
• Nhat Minh Nguyen,
• Duc Anh Ngo,
• Thanh Trang Tran,
• Le Thai Duy,
• Cong Khanh Tran,
• Thi Thanh Van Tran,
• Phan Phuong Ha La and
• Vinh Quang Dang

Beilstein J. Nanotechnol. 2023, 14, 1018–1027, doi:10.3762/bjnano.14.84

• ][18]. Semiconductors are the heart of photodetectors as their bandgap allows for the absorption of photons in the desired wavelength range [19]. There are many semiconductor materials developed for this application. Among them, zinc oxide (ZnO) has been studied extensively over the last decades

• [21]. Regardless, pure ZnO still has the considerable drawback of a wide bandgap (ca. 3.35 eV), which limits its usability for visible-light photodetectors. ZnO absorbs light only in the UV region (less than 4% of the sunlight spectrum) [23]. Extending the operation range of ZnO nanomaterials toward

• properties of ZnO nanostructures, such as bandgap or conductivity [26]. Decorating ZnO with metals such as Ag, Au, Pd, Pt, and Al [27][28] can provide surface plasmonic effects that assist the electron transfer process in materials and extend the light absorption range of a photodetector [29][30]. However

Nanoarchitectonics of photothermal materials to enhance the sensitivity of lateral flow assays

• Elangovan Sarathkumar,
• Rajasekharan S. Anjana and
• Ramapurath S. Jayasree

Beilstein J. Nanotechnol. 2023, 14, 988–1003, doi:10.3762/bjnano.14.82

• nanomaterials. When excited by photons with an energy greater than or equal to the bandgap of the materials, electron–hole pairs are generated. The electrons excited to the conduction band will leave holes in the valence band. The relaxation of these electrons can occur radiatively in the form of photons and

Isolation of cubic Si₃P₄ in the form of nanocrystals

• Polina K. Nikiforova,
• Sergei S. Bubenov,
• Vadim B. Platonov,
• Andrey S. Kumskov,
• Nikolay N. Kononov,
• Tatyana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2023, 14, 971–979, doi:10.3762/bjnano.14.80

• , and UV–vis spectrophotometry. For the isolated cubic Si3P4 phase, a cell parameter of a = 5.04 Å was determined, and the bandgap was estimated to be equal to 1.25 eV. Because of the nanoscale dimensions of the obtained Si3P4 nanoparticles, the product may exhibit several exceptional properties as a

• agglomeration for at least a month. The synthesized samples were brown powders that formed brown sols in acetonitrile, quite similar in appearance to those of Si NPs. Upon examination of the UV–vis absorption spectra, a bandgap of 1.25 eV was established using Tauc plot (Figure 5). A simpler approach for a

• disordered semiconductor material would be to find the energy at which the attenuation coefficient exceeds 104 cm−1 (the optical gap estimated this way amounts to 2.3 eV). All of these observations disprove earlier theoretical assumptions of defective zinc blende Si3P4 as being a narrow-bandgap semiconductor

Cross-sectional Kelvin probe force microscopy on III–V epitaxial multilayer stacks: challenges and perspectives

• Mattia da Lisca,
• José Alvarez,
• James P. Connolly,
• Nicolas Vaissiere,
• Karim Mekhazni,
• Jean Decobert and
• Jean-Paul Kleider

Beilstein J. Nanotechnol. 2023, 14, 725–737, doi:10.3762/bjnano.14.59

• 600 °C. Note that the GaInAsP:Zn layer is an intermediate layer with a doping concentration of 6 × 1018 cm−3 with the purpose to smooth the InP:Zn/GaInAs:Zn transition bandgap and to reduce contact resistances. Finally, a GaInAs:Zn contact layer was made at a lower temperature of 580 °C in order to

• crosstalk [17]. The laser beam deflection system in our AFM employs a laser wavelength of 1310 nm, which is well below the bandgap of our sample; therefore, the parasitic laser absorption, which may interfere with the KPFM measurement, is reduced to negligible levels [13]. Highly doped n+-Si ARROW EFM tips

• have compared the ideal structure free of surface defects to three different cases in which identical acceptor-like and donor-like surface defects densities of 1 × 1012, 1 × 1013, and 5 × 1013 eV−1·cm−2 (taken to be constant throughout the bandgap) were introduced at the surface. The results are

The microstrain-accompanied structural phase transition from h-MoO₃ to α-MoO₃ investigated by in situ X-ray diffraction

• Zeqian Zhang,
• Honglong Shi,
• Boxiang Zhuang,
• Minting Luo and
• Zhenfei Hu

Beilstein J. Nanotechnol. 2023, 14, 692–700, doi:10.3762/bjnano.14.55

• from +2 to +6 [1][2], leading to a range of molybdenum oxides. Molybdenum oxides include the fully stoichiometric MoO3 with a large bandgap above 2.7 eV, the reduced oxides MoO3−x with oxygen vacancies, and the semimetal MoO2. The degree of reduction influences the bandgap energy of molybdenum oxides

Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

• Akeem Adeyemi Oladipo,
• Saba Derakhshan Oskouei and
• Mustafa Gazi

Beilstein J. Nanotechnol. 2023, 14, 631–673, doi:10.3762/bjnano.14.52

• already described, the following is a brief outline of some of the desirable qualities of MOFs that are required for developing opto-electrochemical sensors. Electronic properties: Electrostatic potential, density of states, electron density, bandgap, and conductivity are some of a MOF’s crucial

• simulations based on density functional theory with periodic boundary conditions. In comparison to the building units, they noticed that MOFs have a charge distribution that remains constant, and their electronic properties show a wide range of bandgap energies categorized as insulators or semiconductors. The

• authors pointed out that metal clusters (for example, isoreticular MOFs) essentially define the overall electronic properties of MOFs and provide MOFs with the characteristics of a wide-bandgap semiconductor like ZnO. The size of the organic linker and the hybridization of the central atom of the linker

Titania nanoparticles for photocatalytic degradation of ethanol under simulated solar light

• Evghenii Goncearenco,
• Iuliana P. Morjan,
• Claudiu Teodor Fleaca,
• Florian Dumitrache,
• Elena Dutu,
• Monica Scarisoreanu,
• Valentin Serban Teodorescu,
• Alexandra Sandulescu,
• Crina Anastasescu and
• Ioan Balint

Beilstein J. Nanotechnol. 2023, 14, 616–630, doi:10.3762/bjnano.14.51

• components to substances that catalyze decomposition processes. They have a bandgap that varies from one material to another. Titanium dioxide is a semiconductor material and has been investigated, at first, for solar cells [1][2][3][4] and as optoelectronic component [5][6][7]. In recent years, it has been

• ][18]. Moreover, investigations have shown the possibility for applying TiO2 in hydrogen production by water decomposition [19][20][21][22][23]. Given the TiO2 bandgap, it is considered a low-efficiency material in photodriven water splitting, because only 3% of the solar light can be used. Different

• approaches were tried to reduce the bandgap [24] by doping with, for example, nitrogen [17]. Recent investigations have shown a possible application of TiO2 for the photocatalytic production of hydrogen from water with the aid of sacrificial agents, such as methanol, ethanol, or glycols [21][22]. There are

Observation of multiple bulk bound states in the continuum modes in a photonic crystal cavity

• Rui Chen,
• Yi Zheng,
• Xingyu Huang,
• Qiaoling Lin,
• Chaochao Ye,
• Meng Xiong,
• Martijn Wubs,
• Yungui Ma,
• Minhao Pu and
• Sanshui Xiao

Beilstein J. Nanotechnol. 2023, 14, 544–551, doi:10.3762/bjnano.14.45

• patterns. Here, photonic-crystal BIC cavities encircled by the photonic bandgap of lateral heterostructures are designed. The mirror-like photonic bandgap exhibits strong side leakage suppression to confine the mode profile in the designed cavity. Multiple bulk quantized modes are observed both in

• levels, similar to the quantization of electronic states in quantum dots. Each quantized BIC mode has its specific bulk mode profile and radiation pattern. Combining a photonic bandgap perimeter with the finite-size BIC cavity could significantly prevent transverse leakage, thus giving rise to ultrahigh

• reflective boundary around the BIC cavity [29][30], a bandgap mirror and transition area surrounding the designed BIC cavity are proposed. We numerically evaluate the bulk band diagram of the corresponding infinite BIC structure as well as the multiple quantized bulk mode profiles of the finite-size BIC

Conjugated photothermal materials and structure design for solar steam generation

• Chia-Yang Lin and
• Tsuyoshi Michinobu

Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36

• semiconductor materials, optical absorption significantly varies with the wavelength, depending on the bandgap energy. When semiconductor materials are irradiated with light, electron–hole pairs with energies close to the bandgap are produced. The excited electrons eventually return to a lower energy state and

• -conjugated bonds creates the primary carriers that absorb light and generate thermal energy. This is because the π bonds are usually much weaker than the σ bonds (e.g., C=C π bond energy = 272 kJ·mol−1, C–C σ bond energy = 439 kJ·mol−1) [5]. After excitation by light above the bandgap, electrons in organic

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• bandgap engineering of porous graphene nanoribbons via their width and edge arrangement, periodic nanostructures provide a means to control the electronic properties of graphene nanoribbons. Ma, Tan, Wang, and co-workers have synthesized 5,8-dibromopicene on Au(111) surfaces via trans- and cis-coupling to

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• absorbed light to heat by these particles, has led to thriving research regarding the utilization of plasmonic nanoparticles for a myriad of applications. The design of conventional nanomaterials for PT conversion has focussed predominantly on the manipulation of photon absorption through bandgap

• various material phenomena other than bandgap absorption for heat generation in nanoparticles (NPs), leading to a rapid proliferation of materials for the same. For example, organic materials undergo rapid internal relaxation by the PT effect and are often desired in cancer treatment research as they

• . When the energy of the photons is greater than the bandgap, interband transitions are observed. As an example of the energies at which interband transitions [28] occur, Cu, Au, Ag exhibit them at 2.25, 2.4, and 4 eV, respectively, and threshold energy levels of interband transitions are 1.6–1.8 eV for

Quasi-guided modes resulting from the band folding effect in a photonic crystal slab for enhanced interactions of matters with free-space radiations

• Kaili Sun,
• Yangjian Cai,
• Uriel Levy and
• Zhanghua Han

Beilstein J. Nanotechnol. 2023, 14, 322–328, doi:10.3762/bjnano.14.27

• are introduced into large-scale periodic structures [1]. Extremely high Q-factors can be achieved thanks to the bandgap associated with the periodic structure, which prevents the leakage of radiation into the surrounding environment. Whispering gallery modes supported by dielectric spheres or

• suspended disks made of high-index materials are another example of resonances to provide ultrahigh Q-factors [2]. However, above structures are still bulky. For example, the photonic crystal cavities need the surrounding periods to provide the bandgap, which is not favorable for nanoscale applications

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• ultraviolet light in the solar spectrum due to its broad bandgap of 3.2 eV, which limits the use of visible light. Because of this, the potential photocatalytic use of TiO2 is constrained and the photocatalytic effectiveness is reduced [19][20][25]. Table 1 compares some of the salient characteristics of some

• , nanometre-sized photocatalysts based on bismuth have recently been investigated and evaluated, because the majority of bismuth-based photocatalysts have a bandgap below 3.0 eV, making them usable in visible light. Additionally, their electrical structure produces a valence band with hybrid O 2p and Bi 6s

• between the T-point band (valence) and the L-point band (conduction) [76][77][78]. Note that a reduction of the crystallite size below a critical value can result in a semimetal-to-semiconductor transition [77][78][79][80]. For instance, according to Qi et al. [81], indirect bandgap semiconductors were

High–low Kelvin probe force spectroscopy for measuring the interface state density

• Ryo Izumi,
• Masato Miyazaki,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• show that the analysis of electrostatic forces in the depletion region at high- and low-frequency AC bias voltages provides information about the interface state density in the semiconductor bandgap. As a preliminary experiment, high-low KPFS measurements were performed on ion-implanted silicon

• states within the bandgap difficult. Thus, a method for measuring the energy distribution of the interface states must be developed. Kelvin probe force spectroscopy (KPFS) or electrostatic force spectroscopy is a technique that enables energy spectroscopy of interface states in the semiconductor bandgap

• interface state density in the semiconductor bandgap. We also demonstrate using a pn-patterned silicon substrate that the interface state density can be measured. Theory To understand the principle of the high–low KPFS proposed in this study, we discuss the electrostatic forces acting between the tip and