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

• bending between the carriers. However, when the gate bias that is supplied is greater than the threshold voltage of the device, the type of the channel is inverted which permits the current to flow and turns on the transistor [52]. The FET-based biosensors consist of two dissimilar transduction mechanisms

• concurrently shifts the threshold voltage and modifies the drain current via channel conductivity modulation. The difference between the current (threshold voltage) in the presence of biomolecules and the current without biomolecules is used to define the current sensitivity. The second transduction mechanism

• dielectric constant inside the cavity resulting in a gating effect modulation and subsequent alteration in channel conductivity. This leads to a change in both threshold voltage and drain current, manifesting the presence of target biomolecules in the cavity, and the corresponding sensitivity is defined

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

• low work function is placed in a high-k HfO2 layer in the source–channel region. The device is examined by the parameters Ioff, subthreshold swing, threshold voltage, and Ion/Ioff ratio. The introduction of a live metal strip in the dielectric layer closer to the source–channel interface results in a

• excellent improvement in TFETs, an on-current of 1.00 × 10−5 A/μm, an Ion/Ioff ratio of 7.14 × 1011, and a threshold voltage of 0.28 V. Keywords: dual low-work-function live strip (DLWLS); low-k dielectric spacer; low-work-function live strip (LWLS); Miller capacitance; molybdenum; subthreshold swing (SS

• is greater. Thermionic emission affects the off-to-on transition. A small subthreshold swing is needed to turn the device to an off-state sharply, once Vgs drops below the threshold voltage (VT). Tunnel field-effect transistors (TFETs) work based on band-to-band tunneling and not on conventional

Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes

• Max Mennicken,
• Sophia Katharina Peter,
• Corinna Kaulen,
• Ulrich Simon and
• Silvia Karthäuser

Beilstein J. Nanotechnol. 2022, 13, 219–229, doi:10.3762/bjnano.13.16

• increases linearly with the intensity of the irradiating light, while they exhibit on/off ratios of less than 1.01 for light intensities of 1 µW/cm2. We find an increase of the photocurrent through the Ru(MPTP)2–AuNP devices due to irradiation above a threshold voltage of about 0.4 to 0.5 V (Figure 6a

• needs a minimum energy of about 500 meV (Figure 6a), which is sufficient to initiate charge transport to the electrodes. Raising USD over this threshold voltage leads to a further increase in current. Consequently, we assume, that in Ru(MPTP)2–AuNP devices a plasmon-induced metal-to-ligand charge

Measurement of polarization effects in dual-phase ceria-based oxygen permeation membranes using Kelvin probe force microscopy

• Kerstin Neuhaus,
• Christina Schmidt,
• Liudmila Fischer,
• Wilhelm Albert Meulenberg,
• Ke Ran,
• Joachim Mayer and
• Stefan Baumann

Beilstein J. Nanotechnol. 2021, 12, 1380–1391, doi:10.3762/bjnano.12.102

• certain threshold voltage can lead either to oxidation or reduction of the Fe, Co, or even Ce in the samples (depending on the sign of the applied potential). This would lead to an increase or decrease in the slope of the polarization curve. If the reaction is reversible, it would depend on the velocity

Amorphized length and variability in phase-change memory line cells

• Nafisa Noor,
• Sadid Muneer,
• Raihan Sayeed Khan,
• Anna Gorbenko and
• Helena Silva

Beilstein J. Nanotechnol. 2020, 11, 1644–1654, doi:10.3762/bjnano.11.147

• was calculated using the measured voltage at which the threshold switching occurred and the expected drifted threshold field at that time. The measured threshold voltage values and, hence, the extracted amorphized length, generally increase linearly with the programmed resistance levels. However

• , significant variability arises from the intrinsically unique crystallization and amorphization processes in these devices. For example, cells programmed to an amorphous resistance of approx. 50 MΩ show threshold voltage values of 5.5–7.5 V, corresponding to amorphized length values of 290–395 nm. This

• simulation results obtained from the “simulation program with integrated circuit emphasis” (SPICE). The measured threshold voltage, and the drifted threshold field at that time are used to extract the amorphized length (Figure 1). A literature review of threshold switching in PCM Threshold switching is a

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

• cm−2 [13][14][15][16][17], as well as good electrical conductivity for up to approx. 1018 ions cm−2 [9][10][18]. Sulfur vacancies (SVs) and the formation of a dislocation–divacancy complex can lead to significant n-doping in MoS2 [19], which shifts the threshold voltage (Vth) of the FET to higher

• spread of a typical focused He+ ion probe is several nanometers, the formation of other defects in the irradiated 2D crystal lattice is also expected [25][26], which may bring about the often-observed negative shifts of the MoS2 FET threshold voltage after ion irradiation. Such n-type doping behavior

• oxide, as the source of donor states in the FET channel [35]. Further studies on flakes decoupled from the substrate need to be performed to clarify the exact origin of the threshold voltage shift in TMDs irradiated at moderate beam energies. The effects of increasing IR are evident from changes to the

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• curves of A4Z6-6 and A4Z6-24 GNMs in comparison with a graphene device. The devices made from GNMs exhibit different transport characteristics than GNR and graphene devices. They have threshold voltage and behave like a diode at positive voltages. These effects are attributed to the formation of a

Four self-made free surface electrospinning devices for high-throughput preparation of high-quality nanofibers

• Yue Fang and
• Lan Xu

Beilstein J. Nanotechnol. 2019, 10, 2261–2274, doi:10.3762/bjnano.10.218

• maximal. The jet initiation in the OSFSE process viewed from the side by a high-speed camera is shown in Figure 4. Immediately after a voltage of 40 kV (which is above the threshold voltage) is applied to the solution surface, a deformation of the fluid is observed at the top edge of the solution

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• sensors have a super-Nernstian sensitivity and reference-less nature. This organic charge-modulated field-effect transistor mechanism is attributed to the variation of the threshold voltage in the organic field-effect transistor induced by charge variation upon the presence of a charge (protonation, etc

Molecular attachment to a microscope tip: inelastic tunneling, Kondo screening, and thermopower

• Rouzhaji Tuerhong,
• Mauro Boero and
• Jean-Pierre Bucher

Beilstein J. Nanotechnol. 2019, 10, 1243–1250, doi:10.3762/bjnano.10.124

• vibration modes of transition-metal phthalocyanines [29][30], the two steps at |Vth| = 110 ± 5 mV are easily assigned to the excitation of the stretching of the Mn–Niso bonds of the MnPc molecule. The conductance step ΔG at the positive threshold voltage of 110 ± 5 mV, corresponds to an increase in the

• the sample bias voltage from −250 over −108 to −103 mV, first, and then from −197 over −250 to −300 mV, while the tunneling current is kept constant at 0.12 nA. (c) Variation of the satellite peak threshold voltage as a function of the gap resistance in (a) and (b). (d) Schematic view of the molecular

Electroluminescence and current–voltage measurements of single-(In,Ga)N/GaN-nanowire light-emitting diodes in a nanowire ensemble

• David van Treeck,
• Johannes Ledig,
• Gregor Scholz,
• Jonas Lähnemann,
• Mattia Musolino,
• Abbes Tahraoui,
• Oliver Brandt,
• Andreas Waag,
• Henning Riechert and
• Lutz Geelhaar

Beilstein J. Nanotechnol. 2019, 10, 1177–1187, doi:10.3762/bjnano.10.117

• point most certainly two NWs are contacted, resulting in half the series resistance compared to that of the single-NW measurements C, E, and G. Another parameter that can be extracted from the I–V behavior is the threshold voltage Vth, which is defined as the zero-crossing of the linear fit function of

• exhibit diode characteristics similar to ensemble measurements. However, the threshold voltage and ideality factor are significantly higher for the single NW experiments, likely because of a high contact resistance between tungsten probe tip and p-GaN NW top. Taking this effect into account, the two types

• example for a linear fit to the I–V curve of NW C for the current range from 60 to 100 nA from which the series resistance Rtot and the threshold voltage Vth are derived. The inset depicts the I–V behavior of the ensemble. (b) Semi-log plot of the I–V curve (blue dots) of NW E and the respective fit

Nanocomposite–parylene C thin films with high dielectric constant and low losses for future organic electronic devices

• Marwa Mokni,
• Gianluigi Maggioni,
• Abdelkader Kahouli,
• Sara M. Carturan,
• Walter Raniero and
• Alain Sylvestre

Beilstein J. Nanotechnol. 2019, 10, 428–441, doi:10.3762/bjnano.10.42

• polymers as gate dielectrics presents several advantages for the improvement of the electronic device properties such as higher dielectric constant [35] and dielectric strength [36], reduced threshold voltage [37], increased charge mobility and reduced leakage current [38]. Compared to pure parylene C and

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• /bjnano.10.7 Abstract We report a threshold voltage decrease in a nematic liquid crystal compound, 4-cyano-4′-pentylbiphenyl (5CB), doped with graphene oxide (GO) flakes at a concentration of 0.05–0.3 wt %. The threshold voltage decrease was observed at the same concentration in electro-optic and

• presence of the electric field was discussed. Keywords: graphene oxide; liquid crystal; nematic phase; switching; threshold voltage; Introduction Liquid crystals (LCs) are classified as a type of soft matter which are characterized by anisotropic molecules and a liquid-like fluidity behavior. Of all LC

• Frédericksz effect, the deformation of a homogeneous layer of a NLC is caused by the electric field E, which is initially perpendicular to the director. Such structural transition appears at a certain magnitude called the threshold voltage, Uth. When the applied voltage, U, is lower than the threshold U < Uth

Exploring the photoleakage current and photoinduced negative bias instability in amorphous InGaZnO thin-film transistors with various active layer thicknesses

• Dapeng Wang and
• Mamoru Furuta

Beilstein J. Nanotechnol. 2018, 9, 2573–2580, doi:10.3762/bjnano.9.239

• works have highlighted that the electrical properties of the device (for both the initial and after stress conditions) such as threshold voltage, on/off ratio, and field effect mobility, can be effectively adjusted by controlling the active layer thickness [19][20][21][22][23]. Up to now, the impact of

• thicknesses were prepared by magnetron sputtering. The initial electrical properties and the photoleakage current of a-IGZO TFTs with various active layer thicknesses were investigated. The subthreshold value slightly increased while the threshold voltage (Vth) and mobility (μ) decreased with increasing TIGZO

• active layer thicknesses (TIGZO) measured at VDS = 20.1 V are shown in Figure 1b. Table 1 summarizes the electrical properties, such as field effect mobility in the saturation region (μsat), threshold voltage Vth (VGS at IDS of 1 nA), hysteresis of the transfer curves (the difference of VGS at IDS of 1

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• region. The “doping” due to the presence of the SiO2 coating is taken into consideration as a volume, active dopant concentration (see Supporting Information File 1); the presence of the Si3N4 layer underneath the gate is accounted for by an appropriate shift of the threshold voltage of the transistor

The role of the Ge mole fraction in improving the performance of a nanoscale junctionless tunneling FET: concept and scaling capability

• Hichem Ferhati,
• Fayçal Djeffal and
• Toufik Bentrcia

Beilstein J. Nanotechnol. 2018, 9, 1856–1862, doi:10.3762/bjnano.9.177

• current. This is due to the smaller band gap energy of Ge, yielding a higher tunneling efficiency. Moreover, the higher electron mobility of Ge (3900 cm2·V−1·s−1) contributes to the increased drain current at the threshold voltage as compared to the conventional design with silicon (1400 cm2·V−1·s−1

• current capability as shown in Figure 3a. It can be also concluded that the Ge mole fraction modulates the threshold voltage for the tunnel-current generation, which can in turn influence greatly the subthreshold behavior of the device. Moreover, the proposed Si1−xGex/Si/Ge heterochannel enables a

Effect of ferroelectric BaTiO₃ particles on the threshold voltage of a smectic A liquid crystal

• Abbas R. Imamaliyev,
• Mahammadali A. Ramazanov and
• Shirkhan A. Humbatov

Beilstein J. Nanotechnol. 2018, 9, 824–828, doi:10.3762/bjnano.9.76

• ferroelectric BaTiO3 particles on the planar–homeotropic transition threshold voltage in smectic A liquid crystals consisting of p-nitrophenyl p-decyloxybenzoate and 4-cyano-4′-pentylbiphenyl were studied by using capacitance–voltage (C–V) measurements. It was shown that the BaTiO3 particles significantly

• reduce the threshold voltage. The obtained result is explained by two factors: an increase of dielectric anisotropy of the liquid crystals and the formation of a strong electric field near polarized particles of BaTiO3. It was shown that the role of the second factor is dominant. The explanations of some

• features observed in the C–V characteristics are given. Keywords: colloidal systems; dielectric permittivity; ferroelectric BaTiO3 particles; smectic A liquid crystals; threshold voltage; Introduction Interest in liquid crystals (LC) as a unique state of matter arises not only from a scientific point of

Dynamic behavior of a nematic liquid crystal with added carbon nanotubes in an electric field

• Emil Petrescu and
• Cristina Cirtoaje

Beilstein J. Nanotechnol. 2018, 9, 233–241, doi:10.3762/bjnano.9.25

• support, θ(−d/2) = θ(d/2) = 0, we obtain the threshold voltage for the Fréedericksz transition: where is the Fréedericksz transition voltage of the nematic. Therefore, when the electric field is applied for a short period of time, the critical voltage for Fréedericksz transition increases in the cell

Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles

• Agata Siarkowska,
• Miłosz Chychłowski,
• Daniel Budaszewski,
• Bartłomiej Jankiewicz,
• Bartosz Bartosewicz and
• Tomasz R. Woliński

Beilstein J. Nanotechnol. 2017, 8, 2790–2801, doi:10.3762/bjnano.8.278

• properties of LCs as they can influence, for example, the LC response time and decrease the Freedericksz threshold voltage [6][7][8]. Promising results were reported for metallic (mostly gold and silver), ferroelectric and dielectric NPs [9][10][11][12]. It appeared that NP/LC molecule size matching can

• nematic–isotropic phase transition temperature [21][22], but with a specific surface coating, the effect can be reversed [23]. The presence of Au NPs in an LC has proven to influence the response time and lower the threshold voltage [24][25][26][27][28]. In this paper we compare four different

• transition temperature and threshold voltage. The latter effect also confirms our observations. As can be seen in Table 2, where the presence of metallic NPs reduced the threshold voltage needed to reorient the LC molecules. For undoped PLCFs, the molecules start switching above 2.4 V/µm and for Au-doped LCs

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• , the threshold voltage of the reorientational response is just a few volts, owing to the relatively large anisotropy of the dielectric permittivity. Analogous effects exist with magnetic fields. However, the threshold magnetic fields are high (B = μ0H ≈ 1 T) as a consequence of the small diamagnetic

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• free charge carriers in the FET channel can be estimated using the relation [53][54][55][56]: where the transconductance gm = dIds/dVg and threshold voltage Vth are obtained from the slope and intercept of the linear region of the Ids–Vg curve, respectively. For a back-gate nanowire FET, the

• = 225.6 K, q = 2.513. The lines in (c) and (d) are the fits of Equation 6 to the experimental points whose values are listed in Table 2. Summary of the channel length (L), average nanowire diameter (d), threshold voltage (Vth), transconductance (gm), hole mobility (μ) and free hole concentration (p), for

Spin-dependent transport and functional design in organic ferromagnetic devices

• Guichao Hu,
• Shijie Xie,
• Chuankui Wang and
• Carsten Timm

Beilstein J. Nanotechnol. 2017, 8, 1919–1931, doi:10.3762/bjnano.8.192

• identical nonmagnetic electrodes [31]. The spin-resolved and the total current calculated using the theory discussed in the previous section are shown in Figure 2a. The SP P = (I↑ − I↓)/(I↑ + I↓) of the current is given in Figure 2b. We have found a step-like current–voltage curve with a threshold voltage

• , which is common in nanojunctions. The spin-up and spin-down currents differ both in threshold voltage and magnitude. This leads to a non-monotonic dependence of the SP on bias, as shown in Figure 2b. In particular, nearly complete SP is obtained in the bias range of [0.7, 1.0] V, which means that strong

• chain without dimerization. In the case of a vanishing (α = 0) or weak (α = 2.0) e–l interaction, the SP occurs as soon as the bias is applied. However, for a strong e–l interaction (α = 4.0), a threshold voltage of about 0.2 V appears. Moreover, the maximum SP and the plateau width at the maximum SP

Parylene C as a versatile dielectric material for organic field-effect transistors

• Tomasz Marszalek,
• Maciej Gazicki-Lipman and
• Jacek Ulanski

Beilstein J. Nanotechnol. 2017, 8, 1532–1545, doi:10.3762/bjnano.8.155

• properties do not change after mechanical tests. The remaining transistor parameters such as charge carrier mobility, subthreshold and threshold voltage also remain practically unaffected by mechanical testing. The threshold voltage value, 0.44 V for the unbent device, became slightly reduced down to 0.42 V

• threshold voltage can be controlled. This effect is mainly attributed to the mechanism of charge trapping at grain boundaries [52]. It was also found in further studies that the growth of C60 on the surface of Parylene C at elevated substrate temperatures leads to the creation of radicals at the interface

• the top-gate dielectric. Parylene was selected as a suitable material because it inflicted no damage to the semiconductor structure, a notion confirmed by relatively high charge carrier mobility of 0.18 cm2/V·s with accompanying threshold voltage below 5 V [24]. As it has already been mentioned

Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• 373 K, which was explained in terms of electron trapping at MoS2/SiO2 interface states. Keywords: contact resistance; mobility; MoS2; temperature dependence; threshold voltage; Introduction Transition metal dichalcogenides (TMDs) are compound materials formed by the Van der Waals stacking of MX2

• , RC, can also have a significant influence on the electrical properties of the device in the on-state, i.e., above the threshold voltage (Vth). In particular, RC is expected to affect, to some extent, the values of Vth and of the field effect mobility μ extracted from the transfer characteristics

• ]. In this paper, we report a detailed temperature dependent investigation of multilayer MoS2 transistors with Ni source/drain contacts, focusing on the role played by the contact both in the subthreshold regime and above the threshold voltage. In contrast to other literature works, mainly focused on

Thickness-modulated tungsten–carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields

• Ismael García Serrano,
• Javier Sesé,
• Isabel Guillamón,
• Hermann Suderow,
• Sebastián Vieira,
• Manuel Ricardo Ibarra and
• José María De Teresa

Beilstein J. Nanotechnol. 2016, 7, 1698–1708, doi:10.3762/bjnano.7.162

• is steadily increased from zero up to the point in which the threshold voltage is reached, which corresponds to the critical current. As can be observed in Figure 7, there is good agreement between the existence of maxima in the critical current and the existence of minima in the resistance–field