Doping Efficiency Research Articles

Mesoporous Carbon Composites Containing Carbon Nanostructures: Recent Advances in Synthesis and Applications in Electrochemistry

Carbon nanostructures (CNs) are various low-dimensional allotropes of carbon that have attracted much scientific attention due to their interesting physicochemical properties. It was quickly discovered that the properties of CNs can be significantly improved by modifying their surface or synthesizing composites containing CNs. Composites combine two or more materials to create a final material with enhanced properties compared with their initial components. In this review, we focused on one group of carbon materials—composites containing CNs (carbon/CN composites), characterized by high mesoporosity. Particular attention was paid to the type of synthesis used, divided into hard- and soft-templating methods, the type of polymer matrix precursors and their preparation method, heteroatom doping, pore formation methods, and correlations between the applied experimental conditions of synthesis and the structural properties of the composite materials obtained. In the last part, we present an updated summary of the applications of mesoporous composites in energy storage systems, supercapacitors, electrocatalysis, etc. The correlations among porous structures of materials, heteroatom doping, and electrochemical or catalytic efficiency, including activity, selectivity, and stability, were also emphasized. To our knowledge, a single review has never summarized pyrolyzed mesoporous composites of polymer-CNs, their properties and applications in electrochemistry.

Growth and characterization of n-type Ga2O3 films on sapphire substrates by APMOVPE

In this study, n-type Ga2O3 thin films were grown on c-plane sapphire substrates by atmospheric pressure metalorganic vapor phase epitaxy using tetraethoxysilane (TEOS) as the silicon (Si) precursor. X-ray diffraction measurements confirmed that the deposited films were polycrystalline, predominantly consisting of the stable β-phase and the metastable κ-phase. Surface and optical characterizations indicated that lower growth temperature and appropriate Si doping reduce the grain size of three-dimensional Ga2O3 islands, thereby enhancing optical transmittance by mitigating surface scattering. Hall effect measurements demonstrated a maximum electron carrier concentration of approximately 1 × 1017 /cm3 at room temperature, while secondary ion mass spectrometry (SIMS) revealed that Si atomic concentrations were exceeding 1 × 1020 /cm3 in all n-type samples indicating low doping efficiency of Si. Carbon (C) impurities were also measured by SIMS with concentrations as the same order or higher than that of Si, implying they may be one of the reasons for the degraded electrical conductivity and originated from incomplete decomposition of the precursors during low temperature growth. From these results, it is crucial to reduce C impurities and enhance surface flatness to improve electrical and optical properties.

Characterization and mid-infrared laser operation in Er:CaF2 single crystal fiber grown by the laser heated pedestal growth method

Er:CaF2 crystal, characterized by low doping and high efficiency, is a suitable material for single-crystal fiber (SCF). 3 at.% Er:CaF2 SCFs were grown using the laser heated pedestal growth (LHPG) method. Significant oxidation-induced whitening phenomena were observed during growth. Increasing the growth rate helped mitigate further deterioration due to oxidation. This is likely because higher growth speeds allow the SCF to quickly move away from temperature ranges conducive to oxidation. As oxidation progressed, the phonon energy of 3 at.% Er:CaF2 SCF increased, causing the emission intensity at ∼ 1 μm to decrease from 77 % in the initial source rod to 6 % in the fully whitened state. Additionally, the lifetime of the 4I11/2 level decreased by approximately 10 times, from 8.988 ms to 0.822 ms. Continuous laser output at ∼ 2.8 μm was achieved using the transparent portion of 3 at.% Er:CaF2 SCF. With an output mirror transmission of 2 %, a maximum output power of 251 mW and a slope efficiency of 15.9 % were obtained. The laser experiment demonstrated the potential application of LHPG-grown Er:CaF2 SCF in ∼ 2.8 μm lasers, but further performance enhancement requires additional strategies to address oxidation issues. This work provides valuable insights into the growth of Er:CaF2 SCF using the LHPG method.

Intense Red Fluorescence From Surface Traps in BaSO4:V5+, Eu3+ and Its Applications.

BaSO4:V5+ synthesized at 1000°C in air exhibits an intense emission band peaking at 495 nm from surface traps assisted by atmospheric oxygen on excitation at 350 nm due to charge transfer from O2- to V5+ in the (VO4)3- tetrahedral complex. BaSO4:Eu synthesized under similar conditions exhibits both Eu2+ (375 nm) and Eu3+ (619 nm) fluorescence. Vanadium codoping quenches the Eu2+ fluorescence but enhances the Eu3+ fluorescence in BaSO4:V, Eu due to charge compensation. However, Eu codoping quenches the vanadium fluorescence by diffusion of vanadium into the crystal, and V2O5 also serves as a flux enhancing Eu3+ doping efficiency in BaSO4 lattice. The 619nm Eu3+ PL emission intensity in BaSO4:V5+, Eu3+ is comparable to 592nm emission from commercial (Y,Gd) BO3:Eu3+. However, V5+ emission shows strong thermal quenching, while Eu3+ emission shows little thermal quenching up to 210°C, making BaSO4:V5+, Eu3+ a promising new red phosphor for improving the color rendering of blue light-based white LED. The ratio of Eu3+ to V5+ fluorescence increases with excitation temperature (30°C°C-180°C) enabling BaSO4:V5+, Eu3+ to be used as a non-contact luminescence thermometer.

High Efficiency n-Type Doping of Organic Semiconductors by Cation Exchange.

Achieving efficient doping in n-type conjugated polymers is crucial for their application in electronic devices. In this study, an n-type doping method is developed based on cation exchange that maintains a high doping level while ensuring a high degree of structural order, leading to significantly improved electrical conductivity. By investigating various dopants and ionic liquids, it is discovered that the choice of dopant influences doping efficiency, while the selection of ionic liquid affects cation exchange efficiency. Through careful selection of suitable dopants and ionic liquids, High doping levels are achieved remarkably in a short period, resulting in the highest conductivity (nearly 1×10- 2Scm-¹) compared to other doping methods for poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (N2200). The findings highlight the robustness and efficiency of cation exchange doping as an effective approach for achieving high-quality n-type doping in conjugated polymers, thereby opening new avenues for the development of advanced polymer-based electronic devices.

Lead-free Cs2TiBr6 perovskite solar cells achieving high power conversion efficiency through device simulation

Recently, lead-based perovskite solar cells (PSCs) have gained significant attention in the photovoltaic industry due to their remarkable properties such as high bandgap and high absorption coefficient. However, challenges such as toxicity, instability, and short shelf life limit the use of inorganic-organic lead-based PSCs. To address these issues, researchers introduced eco-friendly, lead-free, and stable cesium titanium (Cs2TiBr6) single-halide absorber material. The aim of this work is to perform the numerical modelling and simulation of FTO/SnO2/Cs2TiBr6/CBTS/Au structure incorporating interfacial defect layers (IDL) using SCAPS-1D to examine and study its characteristics properties about various photovoltaic (PV) parameters such as light-absorbing layer thickness, charge transport layer thickness, doping, defect density, operating temperature, and quantum efficiency (QE). After evaluating these parameters, the proposed single-halide Cs2TiBr6-based structure shows superior performance as compared to previously reported experimental and simulation-based Cs2TiBr6 perovskite structures. The results show a maximum power conversion efficiency (PCE) of 24.24 %, with a fill factor (FF) of 88.9 %, an open-circuit voltage (VOC) of 1.31 V, and a short-circuit current density (JSC) of 20.76 mA/cm2. This work encourages researchers to develop low-toxic, and stable PSCs for the future solar cell industry.

Transport and electronic structure properties of MBE grown Sn doped Ga2O3 homo-epitaxial films

In this work, we report the transport, defect state and electronic structure properties of unintentionally doped (UID) and Sn doped β-Ga2O3 homo-epitaxial thin films grown by molecular beam epitaxy (MBE) with electron density ranging from 2.1 × 1016 to 2.8 × 1019 cm−3. The UID film with an electron density of 2.1 × 1016 cm−3 exhibits a notable RT mobility of 129 cm2/Vs and a peak mobility of 900 cm2/Vs at 80 K, achieving the state-of-the-art level for MBE-grown Ga2O3 films. Temperature dependent Hall measurement reveal that Sn dopants have an activation energy of 56.7 meV. Synchrotron-based photoemission spectroscopy were further used to study insights into the evolution of electronic properties induced by Sn doping. An in-gap defect state was observed at the 1.5 eV above the valence band maximum for the Sn-doped Ga2O3 film. The in-gap state acts as self-compensating centers affecting the overall doping efficiency and mobility. Furthermore, photoemission spectroscopic study also reveals an upward surface band bending existing at the surface region of Sn doped Ga2O3 films. The identification of the in-gap state and surface upward band bending have significant implications for understanding the doping mechanisms in Ga2O3 and its electronic device applications.

Synthesis of high‑nitrogen-content doped-g-C3N4 (A new nitrogen source) diamond under high-pressure and high-temperature conditions

This study reports the successful synthesis of high‑nitrogen-content diamond (2723 ppm) within the Fe-Ni-C-N system, utilizing g-C3N4 as a new nitrogen source via the temperature gradient method under high-pressure and high-temperature (HTHP) conditions. The study investigated the role of nitrogen atoms in facilitating the growth of large diamonds with {111} plane orientation. Analysis of crystal morphology, nitrogen defect content, and nitrogen incorporation forms were conducted. As the amount of g-C3N4 increased, the crystal size decreased, the color changed from yellow to green with increasing depth, and the growth rate notably decreased. The Fourier transform microscopy infrared spectroscopy (FT-IR) characterization revealed increased nitrogen content within the crystal due to nitrogen atom introduction. Raman characterization indicated increased residual stress with higher nitrogen content, leading to shifts in Raman peak positions and broadening of half-peak widths of the diamond. Photoluminescence (PL) characterization indicated that g-C3N4 addition increased, resulting in a fading state of NV− and W8 defects. The results indicated that g-C3N4, as a new nitrogen source, exhibited superior doping efficiency within the diamond lattice compared with traditional nitrogen sources. The study offered valuable insights into the preparation and potential applications of high‑nitrogen diamond single crystals.

Deciphering the Role of Native Defects in Dopant‐Mediated Defect Engineering of Carbon Electrocatalysts

AbstractDoping–dedoping chemistry lays the cornerstone for converting heteroatom dopants into intrinsic defects as the emerging active sites of carbon catalysts, but the defect content is yet hindered by inadequate doping efficiencies. Comprehending crucial factors behind the doping of pristine carbon and their correlation to the catalytic properties of dedoped carbon is thus of high significance. Here, the overlooked impact of native defects in pristine carbon on dopant‐mediated defect engineering of carbon catalysts is explicitly unveiled. Intact fullerene (C60), C60‐derived carbon, and carbon black in distinct pentagon/edge defect states are employed as respective precursors to undergo a nitrogen doping–dedoping treatment. Theoretical and experimental evidence consistently indicates that native pentagons change the preferred N doping site from the edge to the basal plane, leading to a substantially higher doping level. Importantly, in addition to pentagons from the removal of zigzag‐edged pyridinic N, N dopants in in‐plane pentagons are more easily dedoped than those in hexagons, generating even more pentagons in a new pentagon–heptagon–pentagon structure as oxygen reduction active sites. The optimized defect‐rich carbon gives an outstanding half‐wave potential of 0.834 V (0.846 V for Pt/C) via the four‐electron pathway, excellent long‐term durability, and prospective applicability in zinc–air batteries.

Using Bulky Dodecaborane-Based Dopants to Produce Mobile Charge Carriers in Amorphous Semiconducting Polymers.

Conjugated polymers are a versatile class of electronic materials featured in a variety of next-generation electronic devices. The utility of such polymers is contingent in large part on their electrical conductivity, which depends both on the density of charge carriers (polarons) and on the carrier mobility. Carrier mobility, in turn, is largely controlled by the separation between the polarons and dopant counterions, as counterions can produce Coulombic traps. In previous work, we showed that large dopants based on dodecaborane (DDB) clusters were able to reduce Coulombic binding and thus increase carrier mobility in regioregular (RR) poly(3-hexylthiophene-2,5-diyl) (P3HT). Here, we use a DDB-based dopant to study the effects of polaron-counterion separation in chemically doped regiorandom (RRa) P3HT, which is highly amorphous. X-ray scattering shows that the DDB dopants, despite their large size, can partially order the RRa P3HT during doping and produce a doped polymer crystal structure similar to that of DDB-doped RR P3HT; Alternating Field (AC) Hall measurements also confirm a similar hole mobility. We also show that use of the large DDB dopants successfully reduces Coulombic binding of polarons and counterions in amorphous polymer regions, resulting in a 77% doping efficiency in RRa P3HT films. The DDB dopants are able to produce RRa P3HT films with a 4.92 S/cm conductivity, a value that is ∼200× higher than that achieved with 3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), the traditional dopant molecule. These results show that tailoring dopants to produce mobile carriers in both the amorphous and semicrystalline regions of conjugated polymers is an effective strategy for increasing achievable polymer conductivities, particularly in low-cost polymers with random regiochemistry. The results also emphasize the importance of dopant size and shape for producing Coulombically unbound, mobile polarons capable of electrical conduction in less-ordered materials.

Mn derived growth of CsPbBr3 nanoplatelets for stable and bright orange emission

Abstract Mn-doped perovskites have been extensively studied in optics, magnetism, and electronics due to their orange emission. However, successful Mn doping required a high Mn/Pb feed ratio. In this paper, Mn-doped CsPbBr3 nanoplatelets (NPLs) with bright orange emission were prepared by a two-step slow thermal injection synthesis. The slow injection of precursors effectively slow-down the crystal growth kinetic process and controls the growth of undoped CsPbBr3 NPLs. This process also significantly improves Mn doping efficiency. Mn doping induced the generation of numerous precursor clusters during the growth of CsPbBr3 NPLs, and the formation of these clusters was crucial for enhancing the doping efficiency. The maximum amount of Mn precursor in CsPb0.83Mn0.17Br3 was 50% of Pb precursors. The photoluminescence quantum yields (PLQYs) of CsPb0.94Mn0.06Br3 NPLs reached up to 80.6%, which was 3.1 times of that of CsPbBr3 NPLs. The PL properties of Mn-doped CsPbBr3 NPLs were significantly enhanced compared with pure CsPbBr3 NPLs. The growth process and luminescence mechanism of Mn-doped CsPbBr3 NPLs were discussed. High PLQYs and efficient Mn doping supplied an ideal approach for the preparation of various CsPbX3 (X = Cl, Br, and I) NCs for commercial applications.

Nitrogen vacancy–acceptor complexes in gallium nitride

We used photoluminescence (PL) spectroscopy and first-principles calculations to investigate GaN doped with Mg, Be, and implanted with Ca. The PL spectra revealed distinct red emission bands (RLA, where A = Be, Mg, and Ca) with maxima between 1.68 and 1.82 eV, each associated with a specific impurity. These bands consistently appeared alongside the green GL2 PL band at 2.33 eV, attributed to nitrogen vacancy (VN). Our calculations suggest that these bands result from recombination via defect complexes of group-II acceptors substituting for Ga with VN (AGaVN, A = Be, Mg, and Ca). The experimental +/0 transition levels for these complexes were estimated to be 0.6, 0.8, and 1.0 eV above the valence band maximum for Mg-, Be-, and Ca-containing complexes, respectively. The radiative recombination is facilitated by excited donor states located close to the conduction band minimum. Furthermore, our theory predicts that ZnGaVN and CdGaVN are stable and possess similar properties, although, no PL was detected from these defect complexes. The presented findings shed light on the identity of compensating donor complexes that impede the efficiency of p-type doping in GaN.

Assessing molecular doping efficiency in organic semiconductors with reactive Monte Carlo.

The addition of molecular dopants into organic semiconductors (OSCs) is a ubiquitous augmentation strategy to enhance the electrical conductivity of OSCs. Although the importance of optimizing OSC-dopant interactions is well-recognized, chemically generalizable structure-function relationships are difficult to extract due to the sensitivity and dependence of doping efficiency on chemistry, processing conditions, and morphology. Computational modeling for an integrated OSC-dopant design is an attractive approach to systematically isolate fundamental relationships, but requires the challenging simultaneous treatment of molecular reactivity and morphology evolution. We present the first computational study to couple molecular reactivity with morphology evolution in a molecularly doped OSC. Reactive Monte Carlo is employed to examine the evolution of OSC-dopant morphologies and doping efficiency with respect to dielectric, the thermodynamic driving for the doping reaction, and dopant aggregation. We observe that for well-mixed systems with experimentally relevant dielectric constants, doping efficiency is near unity with a very weak dependence on the ionization potential and electron affinity of OSC and dopant, respectively. At experimental dielectric constants, reaction-induced aggregation is observed, corresponding to the well-known insolubility of solution-doped materials. Simulations are qualitatively consistent with a number of experimental studies showing a decrease of doping efficiency with increasing dopant concentration. Finally, we observe that the aggregation of dopants lowers doping efficiency and thus presents a rational design strategy for maximizing doping efficiency in molecularly doped OSCs. This work represents an important first step toward the systematic integration of molecular reactivity and morphology evolution into the characterization of multi-scale structure-function relationships in molecularly doped OSCs.

Photoelectric properties of monolayer 1T-CrS2 modified by doping non-metal atoms under strains

Based on the first principle, the change of photoelectric properties of non-metal-doped CrS2 under biaxial tension was studied. The formation energy indicates that the doping system is stable. Studies have shown that the partial doping system achieves a semiconductor metal phase transition. The strain opens the bandgap of the F-doped system, and the system changes from metal to n-type semiconductor. The Te-doped system realizes the transition from indirect bandgap to direct bandgap under the adjustment of 2% strain. The O and Se doping systems realize the reverse regulation of the bandgap under strain, and the conductivity gradually increases with the increase of strain. The absorption efficiency of Te doping under a certain strain is significantly enhanced, the static dielectric properties of the F doping system are increased by more than two times, the absorption spectrum response range is increased, and the absorption capacity of the system is enhanced. This lays a foundation for applying monolayer CrS2 in microelectronics and optoelectronics.

Promoted Na Solubility and Modified Band Structure for Achieving Exceptional Average ZT by Extra Mn Doping in PbTe.

Na doping strategy provides an effective avenue to upgrade the thermoelectric performance of PbTe-based materials by optimizing electrical properties. However, the limited solubility of Na inherently restricts the efficiency of doping, resulting in a relatively low average ZT, which poses challenges for the development and application of subsequent devices. Herein, to address this issue, the introduced spontaneous Pb vacancies and additional Mn doping synergistically promote Na solubility with a further modified valence band structure. Furthermore, the induced massive point defects and multiscale microstructure greatly strengthen the scattering of phonons over a wide frequency range, leading to a remarkable ultralow lattice thermal conductivity of ∼0.42 W m-1 K-1. As a result, benefiting from the significantly enhanced Seebeck coefficient and superior thermal transports, a high peak ZT of ∼2.1 at 773 K and an excellent average ZT of ∼1.4 between 303 and 823 K are simultaneously achieved in Pb0.93Na0.04Mn0.02Te. This work proposes a simple and constructive method to obtain high-performance PbTe-based materials and is promising for the development of thermoelectric power generation devices.

CNT-doped transition metal carbide enables sensitive organic electrochemical transistor based carcinoembryonic antigen aptasensor towards precise lung cancer diagnosis

Effective detection of carcinoembryonic antigen (CEA) plays an important role in the diagnosis of lung cancer. Given the challenges posed by the low abundance and complexity of biosamples, it is urgent to develop sensitive, cost-effective and fast detection strategies. In this paper, a novel platform is developed using doped transition metal carbides as semiconductor materials for organic electrochemical transistor (OECT) aptamer-based sensors to satisfy sensitivity, specificity, rapidity, and low cost. A new material, CNT-doped MXene, was synthesized and utilized in the fabrication of CM-OECATs. The morphology and doping of CNT-doped MXene were validated effectively. 2.0 wt% CNT achieved maximum doping efficiency at transconductance (Gm) of 0.801 ms. Through systematic optimization of temperature, pH, aptamer concentration and incubation time, a wide detection range ranging from 0.1 pg/mL to 100 ng/mL was achieved, and the lower limit was 0.051 pg/mL. Favorable stability (0.819% decline), specificity and repeatability (RSD = 2.05%) were demonstrated. CM-OECATs effectively distinguished between 11 biosamples of lung cancer from 12 healthy controls (AUC = 0.9748, specificity = 0.9565, sensitivity = 0.9978) for the clinics. The test carried out in two batches gave p-values <0.05, indicating the effectiveness of the CM-OECATs in discriminating effectively. In addition, CM-OECATs demonstrated a favourable correlation in 25 clinical samples (y = 0.9782x + 0.7532, R2 = 0.9723). To sum up, an organic electrochemical transistor aptamer-based sensor based on CNT-doped MXene (CM-OECATs) is promising for future real-time monitoring in clinical settings, paving the way for an efficient, cost-effective and highly sensitive detection strategy.

Ion Doped Hollow Silica Nanoparticles as Promising Oligonucleotide Delivery Systems to Mesenchymal Stem Cells.

Oligonucleotide (ON) therapy is a promising treatment for a wide range of complex genetic disorders, but inefficient intracellular ON delivery has hindered clinical translation. Hollow silica nanoparticles (HSN) hold potential as effective ON delivery vehicles since ON can be encapsulated in the hollow core in situ where they are protected from degradation by eg nucleases. However, HSN must be modified to allow degradation and subsequent (sub)cellular ON release. In this report, we investigated the use of ion and fluorescent dye co-doping in the HSN silica matrix to enable HSN degradability and in vitro visualization. HSN were core encapsulated with ON, doped with Ca2+, Cu2+, Zn2+, Se2+ and Sr2+ ions and co-condensed with rhodamine b isothiocyanate (RITC) by a modified reverse microemulsion method. HSN were physiochemically characterized and their biological activity such as uptake and toxicity were evaluated in mesenchymal stem cells (hMSCs). We successfully doped HSN with RITC and Ca2+, Cu2+, Zn2+ and Sr2+ ions. We observed that doping HSN with Ca2+ and Sr2+ enhanced RITC incorporation while ON encapsulation in HSN increased Cu2+ and Zn2+ doping efficiency. Moreover, our dual-doped HSN demonstrated controlled ON release in the presence of intracellular mimicking levels of glutathione (GSH) and limited release in the absence of GSH over 14 days. HSN were biocompatible in hMSCs up to 300µg/mL except for Cu2+ doped HSNs which were cytotoxic even at ~10µg/mL. HSN uptake was influenced by the dopant ion, DNA encapsulation, and HSN concentration, where Zn-HSN showed the lowest and Sr-HSN and Se-HSND, the highest uptake in hMSCs. We report a straightforward one-pot procedure to create ion and fluorescent dye co-doped HSN that can efficiently incorporate ON, as promising new gene vectors.

Hydrazine-driven cation valence regulation and defect engineering in CeVO4 for highly efficient reduction of organic dyes and heavy metal pollutants in the dark

Tetragonal wakefieldite (CeVO4)-like CeVOS catalysts with exceptional performance in catalytic reduction of Cr6+, MB, and RhB pollutants in the presence of NaBH4 under dark was prepared via a green and facile method. Hydrazine reduces V5+ ions to elevate the V4+ contents, and sulfur-doped is employed to balance lattice deviations from electrical neutrality induced by high V4+ concentrations, enhancing overall stability. Hydrazine modulation regulates the V4+/(V4++V5+) ratio, influencing sulfur doping, defect structure, and electron transfer efficiency. The CeVOS catalyst with an optimized V4+/(V4++V5+) ratio of 0.46 with abundant oxygen vacancies and exhibited exceptional catalytic performance. The 100 mL 50 ppm Cr6+, MB, and RhB solution were completely reduced in 10 min and durable stability, after six runs, it still achieved a 98.8% reduction of Cr6+ within 10 min. Response surface methodology (RSM) elucidated variable interactions and their influence on catalytic reduction performance. The model’s robustness is underscored by a predicted R2 of 0.9345. Optimal conditions for pollutant treatment in practical applications are 15 mg of catalyst, 25 mg of sacrificial agent, and a pH value of 6.8. Therefore, the green synthesis of efficient CeVOS catalysts bears excellent promise for industrial wastewater treatment.

Overcoming the Trade‐off Between Efficient Electrochemical Doping and High State Retention in Electrolyte‐Gated Organic Synaptic Transistors

AbstractTo achieve superior device performance such as low threshold voltage Vth, high maximum on‐current Ion,max, and long retention time in electrolyte‐gated organic synaptic transistors, efficient electrochemical doping and high state retention are essential. However, these characteristics generally show a trade‐off relationship. This work introduces an effective strategy to increase retention time while promoting efficient electrochemical doping. The approach involves blending two polymer semiconductors (PSCs) that have the same backbone but different types of side chains. Polymer synaptic transistors (PSTs) with the blend film showed the lowest Vth, highest Ion,max, longest retention time, and superior cyclic stability compared to PSTs that used films containing only one of the PSCs. The improvement in electrical and synaptic properties achieved through the blend strategy is consistently reproducible and comprehensive. It is attributed this improvement to the increased redox activity and constrained morphological changes observed in the blended PSCs during electrochemical doping, as confirmed by several electrochemical characterizations. This work is the first to increase retention time in PSTs without increasing the crystallinity of polymer film or sacrificing the electrochemical doping efficiency, which has been regarded as an unavoidable compromise in this field. This method provides an effective way to tune synaptic properties for various neuromorphic applications.

High efficiency of boron doping and fast growth realized with a novel gas inlet structure in diamond microwave plasma chemical vapor deposition system

High efficiency of boron doping and fast growth realized with a novel gas inlet structure in diamond microwave plasma chemical vapor deposition system