Inversion Charge Research Articles

The complete set of eigenstates in one type of N-multiple quantum wells

We provide a method to obtain a complete set of eigenstates analytically and the corresponding eigenvalues in one type of N-multiple well potentials. The quantum well profile can be adjusted by many different parameters, which could be applicable to many different physical situations. We demonstrate explicitly the series of eigenstates in double and triple well potentials, which can be used to describe Josephson oscillations and other tunneling dynamics conveniently. The analytic solutions can be used to discuss the topological vector potential hidden in the eigenstates of quantum wells, through performing our recently proposed method of extending Dirac’s monopole theory to a complex plane. Our results suggest that each node of eigenfunctions corresponds to the merging of a pair of magnetic monopoles with inverse charge. The underlying monopoles can be used to determine the phase jump of a pure real wave function with nodes, as observed from an experimental viewpoint.

Powering Disturb-Free Reconfigurable Computing and Tunable Analog Electronics with Dual-Port Ferroelectric FET.

Single-port ferroelectric FET (FeFET) that performs write and read operations on the same electrical gate prevents its wide application in tunable analog electronics and suffers from read disturb, especially in the high-threshold voltage (VTH) state as the retention energy barrier is reduced by the applied read bias. To address both issues, we propose to adopt a read disturb-free dual-port FeFET where the write is performed on the gate featuring a ferroelectric layer and the read is done on a separate gate featuring a nonferroelectric dielectric. Combining the unique structure and the separate read gate, read disturb is eliminated as the applied field is aligned with polarization in the high-VTH state, thus improving its stability, while it is screened by the channel inversion charge and exerts no negative impact on the low-VTH state stability. Comprehensive theoretical and experimental validation has been performed on fully depleted silicon-on-insulator (FDSOI) FeFETs integrated on a 22 nm platform, which intrinsically has dual ports with its buried oxide layer acting as the nonferroelectric dielectric. Novel applications that can exploit the proposed dual-port FeFET are proposed and experimentally demonstrated for the first time, including FPGA that harnesses its read disturb-free feature and tunable analog electronics (e.g., frequency tunable ring oscillator in this work) leveraging the separated write and read paths.

Physically constrained learning of MOS capacitor electrostatics

In recent years, neural networks have achieved phenomenal success across a wide range of applications. They have also proven useful for solving differential equations. The focus of this work is on the Poisson–Boltzmann equation (PBE) that governs the electrostatics of a metal–oxide–semiconductor capacitor. We were motivated by the question of whether a neural network can effectively learn the solution of PBE using the methodology pioneered by Lagaris et al. [IEEE Trans. Neural Netw. 9 (1998)]. In this method, a neural network is used to generate a set of trial solutions that adhere to the boundary conditions, which are then optimized using the governing equation. However, the challenge with this method is the lack of a generic procedure for creating trial solutions for intricate boundary conditions. We introduce a novel method for generating trial solutions that adhere to the Robin and Dirichlet boundary conditions associated with the PBE. Remarkably, by optimizing the network parameters, we can learn an optimal trial solution that accurately captures essential physical insights, such as the depletion width, the threshold voltage, and the inversion charge. Furthermore, we show that our functional solution can extend beyond the sampling domain.

Unleashing the power of capacitive deionization: Advancing ion removal with biomass-derived porous carbonaceous electrodes

Capacitive deionization (CDI) is a promising electrochemical technique for the removal and recycling of ions from micro-polluted wastewater but is still hindered by the co-ion expulsion effect and anode oxidation. In this study, these issues are addressed through optimization of both materials and electrochemical systems. A diverse set of porous carbons are prepared using biomass as a precursor and KOH as the activation agent. It is found that direct carbonization and/or KOH activation induce a negative surface charge, whereas intense nitrogen-doping results in an inverse surface charge for all biomass-derived carbons, characterized by the potential of zero charge (Epzc). Density functional theory calculations suggest that the carboxyl group and quaternary N contribute most among other functional groups to the negative and positive charges, respectively. A Epzc-matching asymmetric CDI system is constructed employing negatively charged and positively charged carbons as the cathode and anode, respectively. This configuration, coupled with precise optimization of the cathode-to-anode mass ratio (m-/m+), unlocks a high adsorption capacity of 17.2 mg g−1 for NaCl, surpassing the symmetric system by 84.7 %. Further fine tuning of the m-/m+ ratio results in a removal capacity of 167.4 mg g−1 for Cu2+ ions, which is the highest reported for carbonaceous materials to date.

Influence of Outer Oxide Charges on the Electrostatics of Metal-Insulator-Semiconductor Tunnel Diode

Metal-Insulator-Semiconductor Tunnel Diode (MISTD) has an ultra-thin oxide with thickness less than 3.5 nm. When a MISTD is biased higher than a critical voltage V C, the device will be driven into the deep depletion region [1]. In this biasing condition, the electrostatics of the device will deviate from the behavior of traditional metal-oxide-semiconductor capacitors with thick oxide [1]. Thus, finding out the critical voltage V C is important to predict the electrostatics of a MISTD. In this work, we found that there is a systematic deviation of V C between the theoretical and the experimental values. A model considering the oxide-charge-induced lateral coupling (OCILC) is suggested as a possible mechanism leading to the deviation. With adding effective positive oxide charges of Q eff/q = 2.4-2.6×1011 cm-2, the calculated V C can fit well with the experimental observations.Figs. 1(a) and (b) are the band diagrams of MISTD biased at V TD < V C and V TD > V C, respectively, where V TD is the positive voltage applied on the metal. When V TD < V C, the generated electrons flow -J gen,bulk are able to follow the increase in the inversion charges and leakage current -J tunnel. In this situation, most of the applied V TD drops on the oxide, and the surface band bending of the silicon ψ s keeps around its initial value ψ 0, as shown in Fig. 1(a). In contrast, at V TD > V C, the generated electrons in original depletion region cannot follow the increase of the tunneling current. To keep the balancing of -J tunnel = -J gen,bulk, a large portion of V TD drops on the silicon and leads to an intense increase in ψ s, as shown in Fig. 1(b). The MISTD will operate under a significant non-equilibrium region under this bias condition. The balancing of -J tunnel = -J gen,bulk is finely discussed in [1].Ten MISTDs with distinct oxide thicknesses ranging from 23.7 to 34.4 Å were fabricated to extract V C. The device structure is shown in Fig. 2(a). The shape of the device is a circle with a diameter of 170 µm. From the measured high-frequency capacitance-voltage (HFCV) relations shown in Fig. 2(a), one can observe a flat region before a critical voltage and a quick decrease after the critical voltage. One can further extract surface band bending ψ s by HFCV [2]. The extracted q∆ψ/kT = q(ψ s-ψ 0)/kT is plotted in Fig. 2(b), where ∆ψ is the difference between ψ s and ψ 0. As the definition in [1], we extract V C at q∆ψ/kT = 3. The extract V C v.s. t ox is shown in Fig. 3 as solid symbols. At the same time, theoretical V C from the modeling proposed in [1] is also attached as a solid line. From Fig. 3, we observed a significant difference in V C between the modeling and the experimental.It is suggested that the OCILC causes the deviation of V C. The mechanism of OCILC is plotted in Fig. 4(a). The positive oxide charges outside the electrode will attract electrons at the silicon surface and form a lateral coupling channel. The potential applied on the electrode will laterally transport through the channel and collect the generated electrons from the lateral region. Finally, the balancing of electrons will become -J tunnel = -J gen,bulk-J gen,lateral, as shown in Fig. 4(b). Because of the extra supplement of electrons (-J gen,lateral), the MISTD can hold the quasi-equilibrium status to a higher voltage, and the V C increase. An improved model considering the effect of OCILC is proposed. The calculated result is plotted in Fig. 5. One can observe V C increase with Q eff. When positive Q eff/q is around 2.4-2.6×1011 cm-2, the calculated V C is close to the V C extract from the experimental.In conclusion, we suggested that the oxide charges outside the electrode play an important role in the electrostatics of MISTD. The mechanism of OCILC is proposed to explain the impact. A model considering OCILC is developed to calculate V C and the results fit well with the experimental results.This work was supported by the Ministry of Science and Technology of Taiwan, ROC, under Contract No. MOST 111-2221-E-192-MY3 and the National Science and Technology Council of Taiwan, ROC, under Contract No. NSTC 111-2622-8-002-001.[1] K. W. Lin, K. C. Chen and J. G. Hwu, An Analytical Model for the Electrostatics of Reverse-Biased Al/SiO₂/Si(p) MOS Capacitors With Tunneling Oxide, IEEE Trans. Electron Devices, 69, 1972, (2022)[2] E. H. Nicollian and J. R. Brews, MOS (Metal Oxide Semiconductor) Physics and Technology (Wiley, Hoboken) (1982) Figure 1

An accurate analytical surface potential model of heterojunction tunnel FET

Based on the accurate and efficient thermal injection method, we develop a fully analytical surface potential model for the heterojunction tunnel field-effect transistor (H-TFET). This model accounts for both the effects of source depletion and inversion charge, which are the key factors influencing the charge, capacitance and current in H-TFET. The accuracy of the model is validated against TCAD simulation and is greatly improved in comparison with the conventional model based on Maxwell–Boltzmann approximation. Furthermore, the dependences of the surface potential and electric field on biases are well predicted and thoroughly analyzed.

Identifying Large Charge operators

The Large Charge sector of Conformal Field Theory (CFT) can generically be described through a semiclassical expansion around a superfluid background. In this work, focussing on U(1) invariant Wilson-Fisher fixed points, we study the spectrum of spinning large charge operators. For sufficiently low spin these correspond to the phonon excitations of the superfluid state. We discuss the organization of these states into conformal multiplets and the form of the corresponding composite operators in the free field theory limit. The latter entails a mapping, built order-by-order in the inverse charge n−1, between the Fock space of vacuum fluctuations and the Fock space of fluctuations around the superfluid state. We discuss the limitations of the semiclassical method, and find that the phonon description breaks down for spins of order n1/2 while the computation of observables is valid up to spins of order n. Finally, we apply the semiclassical method to compute some conformal 3-point and 4-point functions, and analyze the conformal block decomposition of the latter with our knowledge of the operator spectrum.

Sec61 channel subunit Sbh1/Sec61β promotes ER translocation of proteins with suboptimal targeting sequences and is fine-tuned by phosphorylation

The highly conserved endoplasmic reticulum (ER) protein translocation channel contains one nonessential subunit, Sec61β/Sbh1, whose function is poorly understood so far. Its intrinsically unstructured cytosolic domain makes transient contact with ER-targeting sequences in the cytosolic channel vestibule and contains multiple phosphorylation sites suggesting a potential for regulating ER protein import. In a microscopic screen, we show that 12% of a GFP-tagged secretory protein library depends on Sbh1 for translocation into the ER. Sbh1-dependent proteins had targeting sequences with less pronounced hydrophobicity and often no charge bias or an inverse charge bias which reduces their insertion efficiency into the Sec61 channel. We determined that mutating two N-terminal, proline-flanked phosphorylation sites in the Sbh1 cytosolic domain to alanine phenocopied the temperature-sensitivity of a yeast strain lacking SBH1 and its ortholog SBH2. The phosphorylation site mutations reduced translocation into the ER of a subset of Sbh1-dependent proteins, including enzymes whose concentration in the ER lumen is critical for ER proteostasis. In addition, we found that ER import of these proteins depended on the activity of the phospho-S/T-specific proline isomerase Ess1 (PIN1 in mammals). We conclude that Sbh1 promotes ER translocation of substrates with suboptimal targeting sequences and that its activity can be regulated by a conformational change induced by N-terminal phosphorylation.

Corrections to “Design-Oriented All-Regime All-Region 7-Parameter Short-Channel MOSFET Model Based on Inversion Charge”

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(Invited, Digital Presentation) Super-Nernstian Isfet Combining Two-Dimensional WSe2/MoS2 Heterostructure with Negative Capacitance

Ion-sensitive field-effect transistors (ISFETs) are quite popular as compact, low-cost biosensors with fast response time and label-free detection1. They can be used as pH sensors or functionalized for complex biomolecule detection. The voltage sensitivity (Sv) in classical ISFETs is fundamentally limited to 59 mV/pH (Nernst limit). Surpassing the Nernst limit requires complex device architectures or novel transport phenomena. Sensitivity beyond the Nernst limit can be achieved using specific device architectures such as dual gate ISFETs2, negative capacitance ISFETs (NC-ISFET)3, tunnel ISFETs4, etc. Compatible architectures can be combined for further enhancements in sensitivity.First, we experimentally demonstrate a super-Nernstian hetero-ISFET that uses 2-D WSe2/MoS2 heterostructure in a double-gated configuration5. The schematic of the device structure is shown in Fig. 1(a) along with its dimensions. The fluid gate to the pH solution is biased at VFG = 0 V and the voltage sensitivity (SV) is extracted by applying bias to the back-gate (VBG). Fig. 1(b) shows the variation of drain current for change in VBG at different pH. The voltage sensitivity is also included in the same graph. The device uses charge screening due to the interface traps and inversion charges at the hetero-interface to modulate the back-gate transconductance (gmb), thereby allowing super sensitivity.Further enhancement in sensitivity is explored using technology computer-aided (TCAD) device simulator tool (Silvaco ATLAS) by integrating with different device architectures. First we model the baseline hetero-ISFET. The 2-D materials were modeled using their material parameters and 3-D equivalents of their density of states. Amorphous hafnium oxide (HfO2) was used as the dielectric. The mobile ions in the electrolyte were modeled as charge carriers in an intrinsic semiconductor, with its effective density of states varying as a function of pH. The simulation model was calibrated with the experimental device (at pH = 7), as shown in Fig. 2(a). The transfer characteristics of the back-gate at different pH and fixed VFG (= 0 V) for the simulated device is shown in Fig. 2(b). We note that the sensitivity from simulations is lower than the experimental device. This is likely due to non-ideal and 2-D material specific factors which are not accounted in simulations. Nevertheless, the simulated device also shows super-Nernstian sensitivity (Fig. 2(b), right axis), validating the model. Hence, the calibrated TCAD model is used as the baseline for further studies.Next, an NC-FE layer (aluminum-doped HfO2) was added to the top fluid-gate stack6. We have used a ferroelectric-metal-insulator-semiconductor (FMIS) stack for the proposed NC-hetero-ISFET. Fig. 3(a) shows the new top-gate stack with the FMI layer, which replaces the top-gate stack in the earlier schematic. The fluid-gate charge (QFG), and drain current (ID) as a function of VFG (VBG = 0 V), were obtained from the TCAD simulations. The 1-D Landau–Khalatnikov (L-K) equations were used to model the voltage across the FE layer (VFE = 2αQFG+4βQ3 FG = V' FG - Vint; where V' FG is the newly computed fluid-gate bias and Vint is the internal node voltage)7. The calculated Vint (for fixed V' FG) is coupled back into the ATLAS simulator to extract voltage sensitivity (SV) by sweeping VBG at different pH values.The fluid-gate transfer curve of the proposed NC-hetero-ISFET, in Fig. 3(b), clearly shows a steeper sub-threshold slope and higher ON current than the baseline device. The corresponding FE layer parameters are shown in Table 1. These improved fluid-gate characteristics contribute to an increased voltage-sensitivity (SV) when VBG is applied. The transfer characteristic (ID v/s VBG, at fixed V' FG) of the NC-hetero-ISFET at different pH values is shown in Fig. 3(c), along with the voltage sensitivity. Further, in Fig. 3(d), we compare the peak SV obtained at different V' FG. There is an improvement in voltage sensitivity (as much as ~ 100 mV/pH) over the baseline device when NC is introduced. The results pave the way for highly sensitive super-Nernstian ISFETs by combining 2-D heterostructure with NC effect.

Modeling of 1D confinement in FD-SOI trigate nanowires at deep cryogenic temperatures

Multi-gate FD-SOI qubit MOS devices were electrically characterized. At deep cryogenic temperatures and in linear regime, oscillations in both the current and the transconductance were observed above threshold. These are likely related to the formation of one-dimensional sub-bands in the silicon active region. A compact model taking into account a 1D density of states (DOS) has been developed in order to fathom how the 1D confinement influences both the inversion charge and the transconductance. The impact of temperature was shown to be crucial in order to distinguish the sub-bands contribution to the transconductance oscillations. Furthermore, the impact of drain voltage was also investigated, showing that the oscillations were smoothed out at high drain biases.

Breaking the subthreshold slope limit in MOSFETs

The Boltzmann limit of the subthreshold swing 2.3kT/q in MOSFETs is a widely-disseminated myth originated from a common amalgam between drain current and mobile charge. We show that the carrier mobility can substantially increase from weak to strong inversion due to the screening of potential fluctuations and Coulomb scattering. The mobility rise enables the current to increase faster than the inversion charge, thus breaking the apparent theoretical limit.

Label-free measurement of reaction rate constants in solution using fluidic dielectrophoresis

We use the fluidic dielectrophoresis (fDEP) motion of a polarizable liquid-liquid electrical interface to quantify reaction rate kinetics of binding interactions in solution. Using a T-shaped microfluidic channel we co-flow two reactant streams side-by-side. Their resulting interface enables controlled diffusive mixing and product formation. We electrokinetically engineer the interface such it is electrical in nature so that one liquid stream possesses a higher electrical conductivity and the other a higher permittivity. When the interface is exposed to a perpendicular alternating current (AC) electric field the electrical mismatch drives it to polarize and displace across the microchannel width in a direction and magnitude that is a function of the electrical properties of the interface and of the field frequency applied. At a low frequency below the inverse interfacial charge relaxation timescale, the high conductive stream displaces into the high permittivity stream. At frequencies above this inverse timescale the direction reverses. At an intermediate “crossover” frequency (COF), the polarization of the interface tends to zero and the displacement ceases. Because interfacial reactions influence the electrical properties, binding dynamics can be quantified using the COF. We measure the COF down the axial length of an interface subjected to binding reactions between CaGreen and Ca2+, and between avidin and biotin. The experimental measurements are in good agreement with an electrokinetically coupled two-dimensional simulation of the reaction-diffusion equations. From this work, we show that the motion of an electrical interface in an electrical field can be utilized to measure kinetic reaction rates in solution phase.

The Perfect Imperfections in Electrocatalysts.

Modern day electrochemical devices find applications in a wide range of industrial sectors, from consumer electronics, renewable energy management to pollution control by electric vehicles and reduction of greenhouse gas. There has been a surge of diverse electrochemical systems which are to be scaled up from the lab-scale to industry sectors. To achieve the targets, the electrocatalysts are continuously upgraded to meet the required device efficiency at a low cost, increased lifetime and performance. An atomic scale understanding is however important for meeting the objectives. Transitioning from the bulk to the nanoscale regime of the electrocatalysts, the existence of defects and interfaces is almost inevitable, significantly impacting (augmenting) the material properties and the catalytic performance. The intrinsic defects alter the electronic structure of the nanostructured catalysts, thereby boosting the performance of metal-ion batteries, metal-air batteries, supercapacitors, fuel cells, water electrolyzers etc. This account presents our findings on the methods to introduce measured imperfections in the nanomaterials and the impact of these atomic-scale irregularities on the activity for three major reactions, oxygen evolution reaction (OER), oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). Grain boundary (GB) modulation of the (ABO3 )n type perovskite oxide by noble metal doping is a propitious route to enhance the OER/ORR bifunctionality for zinc-air battery (ZAB). The perovskite oxides can be tuned by calcination at different temperatures to alter the oxygen vacancy, GB fraction and overall reactivity. The oxygen defects, unsaturated coordination environment and GBs can turn a relatively less active nanostructure into an efficient redox active catalyst by imbibing plenty of electrochemically active sites. Obviously, the crystalline GB interface is a prerequisite for effective electron flow, which is also applicable for the crystalline surface oxide shell on metal alloy core of the nanoparticles (NPs). The oxygen vacancy of two-dimensional (2D) perovskite oxide can be made reversible by the A-site termination of the nanosheets, facilitating the reversible entry and exit of a secondary phase during the redox processes. In several instances, the secondary phases have been observed to introduce the right proportion of structural defects and orbital occupancies for adsorption and desorption of reaction intermediates. Also, heterogeneous interfaces can be created by wrapping the perovskite oxide with negatively charged surface by layered double hydroxide (LDH) can promote the OER process. In another approach, ion intercalation at the 2D heterointerfaces steers the interlayer spacing that can influence the mass diffusion. Similar to anion vacancy, controlled formation of the cation vacancies can be achieved by exsolving the B-site cations of perovskite oxides to surface anchored catalytically active metal/alloy NPs. In case of the alloy electrocatalysts, incomplete solid solution by two or more mutually immiscible metals results in heterogeneous alloys having differently exposed facets with complementary functionalities. From the future perspective, new categories of defect structures including the 2D empty spaces or voids leading to undercoordinated sites, the multiple interfaces in heterogeneous alloys, antisite defects between anions and cations, and the defect induced inverse charge transfer should bring new dimensionalities to this riveting area of research.

Modeling and simulations of FDSOI five-gate qubit MOS devices down to deep cryogenic temperatures

FD-SOI five-gate (5G) qubit MOS devices are electrically characterized in linear regime down to deep cryogenic temperatures. The Lambert-W function is successfully used for the modelling of such 5G MOS devices from subthreshold regime to strong inversion. Its applicability is demonstrated down to deep cryogenic temperatures. The 5G device is modeled as a series of five independent transistors: the “active” one, that directly controls the current, and the “external” ones, that act as access resistances. The Lambert-W function enables to accurately reconstruct the inversion charge and the active channel resistance from weak to strong inversion. This approach allows reproducing the drain current characteristic avoiding the evaluation of the mobility attenuation factors. The main device parameters are extracted versus temperature. Furthermore, the role of different scattering mechanisms has been investigated, underlying the impact of defects for the gates in proximity of source and drain. The experimental characterizations have been completed with some Poisson-solver based simulations, carried out down to cryogenic temperatures. In this regime, Maxwell-Boltzmann carrier statistic has been replaced by an analytical expression of the Fermi-Dirac function.

Local-Oxide-Thinning-Induced Deep Depletion Phenomenon in MOS Capacitors

The influence of local oxide thinning (LOT) spots on the electrostatics of MOS capacitors was studied in this work. The capacitors are found to suffer from severe deep depletion (DD) above threshold once LOT spots that cause significant gate leakage are introduced, making them inapplicable for MOSFETs. With the help of simulation, we proposed the presence of a lateral electric field at the spot edge, which effectively drifts inversion charge toward the spot from its exterior, leading to severe depletion of inversion charge underneath the entire gate area. Capacitor size, spot size and spot thickness effects on the DD behavior were also investigated. This work demonstrates the high influence of LOT spots on device operations, as well as affirming the importance of oxide structural defect control.

A Bottom-Up Scalable Compact Model for Quantum Confined Nanosheet FETs

In this work, a physics-based compact model for channel charges and drain current in nanosheet FETs is presented. The model follows the bottom-up approach. The channel charges are calculated using the 1-D density of states (DOS), which seamlessly scales up for devices with 2-D or 3-D DOS as the confinement reduces in a particular direction. The model uses full Fermi–Dirac (FD) statistics and requires only two additional fitting parameters. The accuracy of the model is confirmed by comparing it with data from in-house 2-D coupled Poisson–Schrödinger (PS) solver and Technology Computer Aided Tool (TCAD) simulations. The proposed model accurately predicts the subband energies, inversion charges, channel potential, and drain current for nanosheet FETs (NsFETs) with different dimensions and applied biases.

Design-Oriented All-Regime All-Region 7-Parameter Short-Channel MOSFET Model Based on Inversion Charge

Design-Oriented All-Regime All-Region 7-Parameter Short-Channel MOSFET Model Based on Inversion Charge

BOX engineering to mitigate negative differential resistance in MFIS negative capacitance FDSOI FET: an analog perspective

Till date, the existing understanding of negative differential resistance (NDR) is obtained from metal-ferro–metal–insulator–semiconductor (MFMIS) FET, and it has been utilized for both MFMIS and metal–ferro–insulator–semiconductor (MFIS) based NCFETs. However, in MFIS architecture, the ferroelectric capacitance (C FE) is not a lumped capacitance. Therefore, for MFIS negative capacitance (NC) devices, the physical explanation which governs the NDR mechanism needs to be addressed. In this work, for the first time, we present the first principle explanation of the NDR effect in MFIS NC FDSOI. We found that the output current variation with the drain to source voltage (V DS), (i.e. g ds) primarily depends upon two parameters: (a) V DS dependent inversion charge gradient (∂n/∂ V DS); (b) V DS sensitive electron velocity (∂v/∂ V DS), and the combined effect of these two dependencies results in NDR. Further, to mitigate the NDR effect, we proposed the BOX engineered NC FDSOI FET, in which the buried oxide (BOX) layer is subdivided into the ferroelectric (FE) layer and the SiO2 layer. In doing so, the inversion charge in the channel is enhanced by the BOX engineered FE layer, which in turn mitigates the NDR and a nearly zero g ds with a minimal positive slope has been obtained. Through well-calibrated TCAD simulations, by utilizing the obtained positive g ds, we also designed a V DS independent constant current mirror which is an essential part of analog circuits. Furthermore, we discussed the impact of the FE parameter (remanent polarization and coercive field) variation on the device performances. We have also compared the acquired results with existing literature on NC-based devices, which justifies that our proposed structure exhibits complete diminution of NDR, thus enabling its use in analog circuit design.

Complextation of Oppositely Charged Polymer: Novel Approaches for Drug Delivery.

The polyelectrolyte complexes (PECs) are adaptable constructs shaped by electrostatic interaction between biopolymers with inverse charges. Polyelectrolyte edifices comprise an exceptional class of polymeric mixtures comprising of polyions with inverse charges, which can be charged either cationically or anionically. Significant advancement has been made in the course of recent years towards new medication conveyance frameworks. The subject of broad, essential and applied exploration covers the marvel of interpolymer collaborations and polyelectrolyte complex development. Basically, applied polyelectrolytes raise on the grounds that the advantages of supportability are perceived in the scholarly world and modern examination settings. Polyelectrolytes are a form of polymer that has endless ionizable practical arrangements. Ionized polyelectrolytes in the arrangement can form a complex with an oppositely charged particle called a polyelectrolyte complex. The review article emphasizes on PECs and their classification, characterization, as well as a critical analysis of the current research and applicability in the drug delivery technology.