Doped Silicon Research Articles

Effect of doping on the optical properties of lanthanum-gallium tantalate

Nominally pure lanthanum-gallium tantalate La3Ga5.5Ta0.5O14 crystals doped with aluminum, silicon and gallium oxide to above stoichiometric content have been grown by the Czochralski technique in iridium crucibles in argon and in agron with addition of oxygen atmospheres. The transmittance spectra of the crystals have been measured on a Cary-5000 UV-Vis-NIR spectrophotometer in the 200–800 nm range. Absorption spectra α(λ) have been plotted on the basis of the experimental data. The absorption spectra of the undoped crystals grown in an oxygen-free atmosphere have one weak absorption band at λ ~ 290 nm. The absorption spectra of the crystals grown in an agron with addition of oxygen have absorption bands at λ ~ 290, 360 and 480 nm. We show that for the crystals grown in an oxygen-free atmosphere, gallium doping to above stoichiometric content reduces the intensity of its only λ ~ 290 nm absorption band. Aluminum doping of the La3Ga5.5Ta0.5O14 crystals grown in an oxygen-free atmosphere significantly reduces the intensity of the λ ~ 290 nm absorption band and increases the intensity of the λ ~ 360 and 480 nm bands. Aluminum doping of the La3Ga5.5Ta0.5O14 crystals grown in an oxygen-containing atmosphere reduces the intensity of the λ ~ 360 and 480 nm bands and increases the intensity of the λ ~ 290 nm absorption band. Silicon doping of these crystals significantly reduces the intensity of the λ ~ 480 nm band and also reduces the intensity of the λ ~ 290 and 360 nm bands.

Examining O[Formula: see text] adsorption on pristine and defective popgraphene sheets: A DFT study.

Popgraphene (PopG) is a two-dimensional carbon-based material with fused pentagonal and octagonal rings. Like graphene, it exhibits a metallic band gap and exceptional thermal, dynamic, and mechanical stability. Here, we theoretically study the electronic and structural properties of PopG monolayers, including their doped and vacancy-endowed versions, as O[Formula: see text] adsorbers. Our findings show that pristine and vacancy-endowed PopG sheets have a comparable ability to adsorb O[Formula: see text] molecules, with adsorption energies ranging from [Formula: see text]0.57 to [Formula: see text]0.59 eV (physisorption). In these cases, octagonal rings play a dominant role in the adsorption mechanism. Platinum and Silicon doping enhance the O[Formula: see text] adsorption in areas close to the octagonal rings, resulting in adsorption energies ranging from [Formula: see text]1.13 to [Formula: see text]2.56 eV (chemisorption). Furthermore, we computed the recovery time for the adsorbed O[Formula: see text] molecules. The results suggest that PopG/O[Formula: see text] interaction in pristine and vacancy-endowed cases can change the PopG electronic properties before O[Formula: see text] diffusion. Density Functional Theory (DFT) simulations, with Van der Waals corrections (DFT-D, within the Grimme scheme), were performed to study the structural and electronic properties of PopG/O[Formula: see text] systems using the DMol3 code within the Biovia Materials Studio software. The exchange and correlation functions are treated within the generalized gradient approximation (GGA) as parameterized by Perdew-Burke-Ernzerhof (PBE) functional. We used the double-zeta plus polarization (DZP) for the basis set in these cases. We also considered the BSSE correction through the counterpoise method and the nuclei-valence electron interactions by including semi-core DFT pseudopotentials.

Vertical-cavity surface-emitting phase shifter.

This study proposes a novel technique for a 2D beam steering system using hybrid plasmonic phase shifters with a cylindrical configuration in a 2D periodic array suitable for LIDAR applications. A nanoscale VCSEP design facilitates a sub-wavelength spacing between individual phase shifters, yielding an expanded field of view and side lobes suppression. The proposed design includes a highly doped sub-micron silicon pillar covered by a thin layer of nonlinear material and an additional conductive metal layer. Characterization of a single VCSEP demonstrated a Free Spectral Range (FSR) of 53.28 ± 2.5 nm and a transmission variation of 3 dB, with VπL equal to 0.075 V-mm.

All silicon MIR super absorber using fractal metasurfaces

Perfect absorbers can be used in photodetectors, thermal imaging, microbolometers, and thermal photovoltaic solar energy conversions. The spectrum of Mid-infrared (MIR) wavelengths offers numerous advantages across a wide range of applications. In this work, we propose a fractal MIR broadband absorber which is composed of three layers: metal, dielectric, and metal (MDM), with the metal being considered as n-type doped silicon (D-Si) and the dielectric is silicon carbide (SiC). The architectural design was derived from the Sierpinski carpet fractal, and different building blocks were simulated to attain optimal absorption. The 3D finite element method (FEM) approach using COMSOL Multiphysics software is used to obtain numerical results. The suggested fractal absorber exhibits high absorption enhancement for MIR in the range between 3 and 9 µm. D-Si exhibits superior performance compared to metals in energy harvesting applications that utilize plasmonics at the mid-infrared range. Typically, semiconductors exhibit rougher surfaces than noble metals, resulting in lower scattering losses. Moreover, silicon presents various advantages, including compatibility with complementary metal–oxide–semiconductor (CMOS) and simple manufacturing through conventional silicon fabrication methods. In addition, the utilization of doped silicon material in the mid-IR region facilitates the development of microscale integrated plasmonic devices.

Formation and Characterization of Freestanding Membranes Based-Porous Silicon Doped Lithium-Ion

Formation and Characterization of Freestanding Membranes Based-Porous Silicon Doped Lithium-Ion

Microporous Hydroxyapatite-Based Ceramics Alter the Physiology of Endothelial Cells through Physical and Chemical Cues.

Incorporation of silicate ions in calcium phosphate ceramics (CPC) and modification of their multiscale architecture are two strategies for improving the vascularization of scaffolds for bone regenerative medicine. The response of endothelial cells, actors for vascularization, to the chemical and physical cues of biomaterial surfaces is little documented, although essential. We aimed to characterize in vitro the response of an endothelial cell line, C166, cultivated on the surface CPCs varying either in terms of their chemistry (pure versus silicon-doped HA) or their microstructure (dense versus microporous). Adhesion, metabolic activity, and proliferation were significantly altered on microporous ceramics, but the secretion of the pro-angiogenic VEGF-A increased from 262 to 386 pg/mL on porous compared to dense silicon-doped HA ceramics after 168 h. A tubulogenesis assay was set up directly on the ceramics. Two configurations were designed for discriminating the influence of the chemistry from that of the surface physical properties. The formation of tubule-like structures was qualitatively more frequent on dense ceramics. Microporous ceramics induced calcium depletion in the culture medium (from 2 down to 0.5 mmol/L), which is deleterious for C166. Importantly, this effect might be associated with the in vitro static cell culture. No influence of silicon doping of HA on C166 behavior was detected.

Magnetic Properties of Silicon with Paramagnetic Impurity Atoms

One of the possible ways to obtain silicon with magnetic properties is the introduction of paramagnetic impurities into silicon: Cr, Mn, Fe, Ni, and Co. In our opinion, silicon materials containing magnetic nanosized clusters are most suitable for spintronic devices. The possibility of obtaining silicon with magnetic properties by diffusion doping was studied in this work. To obtain silicon doped with Cr, Mn, Fe and Ni impurity atoms, p-type single-crystal silicon with a specific resistance of ρ = 5 Ohm·cm and ρ = 0.5 Ohm·cm was used, and for doping with Co atoms, n-type silicon with resistivity ρ=10 Ohm·cm was used. The diffusion temperature and time were chosen such that, after diffusion annealing, the samples with impurity Cr, Fe, and Mn atoms remained highly compensated p-type, and when doped with impurity Co atoms, they remained high-resistance n-type. The results of the study showed that with decreasing temperature, the value of the negative magnetoresistance Δρ/ρ in the Si<Mn> samples increases and reaches its maximum value (about 800%) at T = 240 K, a further decrease in temperature leads to a decrease in the magnetoresistance, and at a temperature T = 170 K, the sign of the magnetoresistance is inverted. In Si <Cr> samples, with decreasing temperature, the positive magnetoresistance turns into a negative one, the value of which increases with decreasing temperature, and is achieved at T=100 K Δρ/ρ = 45–50%. In Si<Fe> samples, with decreasing temperature, the value of negative magnetoresistance increases monotonically and at T=100 K its value is Δρ/ρ = (100÷120) %. The study in Si<Сo> samples showed that with decreasing temperature the value of positive magnetoresistance increases and at Т=100 K it reaches Δρ/ρ = (17÷20) %. The study of magnetoresistance in samples - Si<Ni> showed that with decreasing temperature the value of positive magnetoresistance increases and at T=100 K it reaches Δρ/ρ = (10÷15) %. When studying the magnetic properties of p-Si <B, Mn> samples at low temperatures (below T=30 K), a ferromagnetic state was found, i.e. succeeded in obtaining a magnetic semiconductor material by the method of diffusion of a paramagnetic impurity. In the overcompensated Si <B, Mn> (n‑type) samples, no magnetic hysteresis was found. This shows a significant effect on the magnetic properties of the manganese impurity in silicon of its charge and, accordingly, spin state. Based on the results obtained, it can be argued that diffusion doping of silicon with manganese can be used to obtain silicon with magnetic properties.

Deformation behaviour of the silicon doped metastable Fe50-xMn30Co10Cr10Six complex concentrated alloy using experiments and crystal plasticity simulations

Deformation behaviour of transformative Fe50Mn30Co10Cr10 complex concentrated alloy doped with 0.2 wt % silicon is studied using ex-situ EBSD accompanied with mean and full field crystal plasticity simulations. On silicon doping, martensitic transformation gets suppressed rather nano twinning is observed with tensile deformation. The considerable rise in strength and tensile ductility is attributed to the solid solution strengthening and deformation twinning respectively. Furthermore, crystal plasticity simulations using mean field viscoplastic self-consistent and full field fast Fourier transform FFT approaches are performed to address the texture evolution, the effect of neighbouring grains of different orientations as well as slip and twin activity. Slip is found to be planar in nature which is verified using crystal plasticity simulations. Combination of mean and full field simulations is used to address the effect of neighbouring orientations on the rotation path of individual grains towards the stable end orientation. The critical role of deformation nano twinning in providing extended strain hardening contributing to significant ductility is established. This study highlights the importance of silicon doping in improving the mechanical properties of the Fe50Mn30Co10Cr10 CCA while offering valuable insights into the deformation mechanisms and crystallographic texture evolution.

Integrating Conjugated Polymers with Bacteriorhodopsin to Realize Quasi Dual‐Gate Organic Field‐Effect Transistors

AbstractFour conjugated polymers are integrated with a bacteriorhodopsin D94N‐HmBRI in organic field‐effect transistors (OFETs) with the device architecture of doped Si bottom gate/SiO2 bottom electric/semiconducting polymer/Au electrodes/D94N‐HmBRI top dielectric. Photosensitivity of D94N‐HmBRI in the devices is validated. It is proposed that light activates the conformational change of all‐trans retinal to 13‐cis retinal in D94N‐HmBRI. The D94N‐HmBRI layer then applies momentary dipoles to the semiconductors, affecting threshold voltage, resulting in photosensitivity. Film‐thickness variation, capacitance determination, and grazing‐incidence X‐ray scattering are performed to support the proposed working principle. Quasi dual‐gate OFETs with a highly doped silicon wafer as the bottom gate and light as the top gate are thus realized by combining conjugated polymers with D94N‐HmBRI.

Discovering the Electron Beam Induced Transition Rates for Silicon Dopants in Graphene with Deep Neural Networks in the STEM.

Discovering the Electron Beam Induced Transition Rates for Silicon Dopants in Graphene with Deep Neural Networks in the STEM.

Probing the influence of defects and Si-doping in graphene sheet as an efficacious carrier for drug delivery system in gas and aqua phases - Combined DFT and classical MD simulation

In this study, for the bioavailability and distribution of the drug on the tumor cells we have chosen targeted drug delivery system and for the delivery system, pristine, defected, and doped graphene sheets are chosen with the anticancer drugs as lapachol and β – lapachone which are studied using density functional theory (DFT) for efficacious drug delivery. The defect formation and doping are shown to alter the properties of pristine sheets, which results in the enhanced adsorption of anticancer drugs. The cohesive energy found for all the sheets are in the 7 eV range which shows their high stability. This study revealed that the adsorption of lapachol and β – lapachone in pristine graphene sheet is poor with low adsorption energy of about −1.49 (−1.39) eV and −1.52 (−1.43) eV in gas (water) medium respectively and the adsorption energy is enhanced about 30–70% by introducing defects and about 55% by doping of silicon in the pristine graphene sheet. The highest adsorption energy for both lapachol and β – lapachone are found to be about −2.69 (−2.59) eV and −2.55 (−2.41) eV in mono vacant graphene sheet in gas (water) medium respectively. The major interaction within the complexes is studied using quantum theory of atoms in molecule (QTAIM) analysis and it is further studied via non-covalent interaction (NCI) analysis with the help of reduced density gradient (RDG) map. The ρ values at bond critical points (BCP) lie between 0.007 and 0.01 a. u. With ∇2ρ and H(r) > 0, −G/V > 1 for all the complexes showing that non-covalent interaction plays a major role in the adsorption of active drugs. Furthermore, NCI analysis shows that the van der Waals interaction and hydrogen bonding play a major influence on the interaction between the anticancer drug and the carrier sheets. The molecular dynamic (MD) study shows that all the drug-loaded complexes are stable with minimal variation in the van der Waals energy during the production run. Thus, the results obtained from DFT and MD shows that the defected and Si-doped graphene sheets are much more suitable as a carrier for drug delivery than the pristine sheet. This study paves the way for the future research on the defected and doped graphene sheets as a suitable drug carrier for numerous drugs in the targeted drug delivery system.

Laser Activation for Highly Boron-Doped Passivated Contacts

Passivated, selective contacts in silicon solar cells consist of a double layer of highly doped polycrystalline silicon (poly Si) and thin interfacial silicon dioxide (SiO2). This design concept allows for the highest efficiencies. Here, we report on a selective laser activation process, resulting in highly doped p++-type poly Si on top of the SiO2. In this double-layer structure, the p++-poly Si layer serves as a layer for transporting the generated holes from the bulk to a metal contact and, therefore, needs to be highly conductive for holes. High boron-doping of the poly Si layers is one approach to establish the desired high conductivity. In a laser activation step, a laser pulse melts the poly Si layer, and subsequent rapid cooling of the Si melt enables electrically active boron concentrations exceeding the solid solubility limit. In addition to the high conductivity, the high active boron concentration in the poly Si layer allows maskless patterning of p++-poly Si/SiO2 layers by providing an etch stop layer in the Si etchant solution, which results in a locally structured p++-poly Si/SiO2 after the etching process. The challenge in the laser activation technique is not to destroy the thin SiO2, which necessitates fine tuning of the laser process. In order to find the optimal processing window, we test laser pulse energy densities (Hp) in a broad range of 0.7 J/cm2 ≤ Hp ≤ 5 J/cm2 on poly Si layers with two different thicknesses dpoly Si,1 = 155 nm and dpoly Si,2 = 264 nm. Finally, the processing window 2.8 J/cm2≤ Hp ≤ 4 J/cm2 leads to the highest sheet conductance (Gsh) without destroying the SiO2 for both poly Si layer thicknesses. For both tested poly Si layers, the majority of the symmetric lifetime samples processed using these Hp achieve a good passivation quality with a high implied open circuit voltage (iVOC) and a low saturation current density (J0). The best sample achieves iVOC = 722 mV and J0 = 6.7 fA/cm2 per side. This low surface recombination current density, together with the accompanying measurements of the doping profiles, suggests that the SiO2 is not damaged during the laser process. We also observe that the passivation quality is independent of the tested poly Si layer thicknesses. The findings of this study show that laser-activated p++-poly Si/SiO2 are not only suitable for integration into advanced passivated contact solar cells, but also offer the possibility of maskless patterning of these stacks, substantially simplifying such solar cell production.

In Ukrainian

Investigating the formation of inversion layers (IL) at the Si-SiO2 interface in the manufacturing technology of silicon photodetectors, some dynamics of dislocations after isothermal annealing were revealed, which were absent in samples without inversion. After selective etching of samples with inversion layers, localization of dislocations on the periphery of responsive elements (RE) with accumulation of guard rings (GR) or other elements of n+-type topology outside the RE was observed. This testified to the movement of dislocations on the surface of the Si-SiO2 structures with IL in the direction of the periphery of the crystal during isothermal annealing, which contributed to a significant decrease in the density of structural defects in RE. The described phenomenon can be used to obtain highly doped defect-free silicon structures. Since the presence of dislocations or other violations of the crystal lattice negatively affect the parameters of the products. In the case of using the described phenomenon as a technological method of “cleaning” the surface of silicon structures, there is a need for controlled formation of IL. One of the methods of forming inversion layers can be thermal oxidation in hydrochloric acid vapors according to the principle of dry-wet-dry oxidation (for p-type silicon). Another method that does not require additional materials is the annealing of Si-SiO2 structures at a temperature of 900–950 Celsium degrees in a nitrogen atmosphere for ≥ 240 minutes. Inversion channels, in this case, will be formed due to the redistribution and diffusion of metal impurities in the oxide (which were introduced during previous thermal operations) to the Si-SiO2 interface. In the described case, these structural defects after annealing were localized in the GR, which is also an active element of the phododiodes, as it limits the dark current of the RE, accordingly, the dark current of the GR should also be low. To be able to implement this method, it is necessary to create passive n+-regions on the periphery of the crystals, limited by oxide, which will be the locations of defects after annealing. It can be both separate areas of arbitrary shape and a concentric ring outside the GR. Elements that will be the locations of defects on the periphery can be cut off at the stage of separating the substrates into crystals. After annealing, it is necessary to remove the IL and form an anti-reflective coating by any known method, since the presence of inversion channels contributes to the growth of dark currents. When examining the morphology of defect localization areas after annealing under high-magnification microscopes and with the help of an atomic force microscope, the formation of hexagonal and round defects, which are partial marginal Frank dislocation loops, was observed. The mechanism of dislocation movement described in this article has not been thoroughly studied by us and requires additional research, but it may be related to Cottrell atmospheres and their interaction with IL

Study on the growth characteristics of type Ⅰb silicon-doped diamond in FeNi catalyst under high temperature and pressure

Silicon-related impurities are widely present in natural diamonds. Exploring the properties of silicon-doped diamonds provides vital guidelines for elucidating the composition of the mantle and the growth mechanism of natural diamonds. In this study, a high-capacity cubic high-pressure device was used to simulate the high-temperature and high-pressure environment for diamond growth. The regulation of transition-metal solvent catalyst (silicon) in the crystallization process, morphology, and impurity concentration of diamond crystals is reported. In a series of experiments, silicon powder was added to regulate its concentration in the diamond growth system. An Fe/Ni alloy was used as the catalyst, with a pressure of 5.8 GPa, a temperature range of 1600–1700 K, and a growth time of 12 h. As the silicon concentration increased, the diamond crystal displayed a slower growth rate, its color changed from yellow to light yellow, and the number of diamond inclusions gradually increased. The nitrogen concentration in the diamond crystals gradually decreased from 279 to 68 ppm, and nitrogen mainly existed in the form of single atoms (C-centers). Raman data showed that the Si-doped diamond crystal displayed a high-quality sp3 structure. The first-order Raman peak of the Si-doped diamond shifted from 1331.75 to 1331.18 cm−1, and its half-peak width increased from 4.18 to 5.41 cm−1. Silicon doping can increase the internal stress of the diamond crystal and decrease its crystalline quality. The X-ray photoelectron spectroscopy results of the diamond crystal indicated that silicon in the Fe–Ni–C–Si system entered into the diamond lattice. The photoluminescence spectroscopy results revealed that after silicon atoms entered the diamond lattice, crystal defects and more vacancies were formed. The vacancies combined with displaced nitrogen atoms to form nitrogen-vacancy centers. Moreover, this study provides guidelines for exploring the formation environment and morphology of natural diamonds.

Effect of Carrier Gas on Silicon Doped GaN Epilayer Characteristics

Effect of Carrier Gas on Silicon Doped GaN Epilayer Characteristics

Periodic Arrays of Dopants in Silicon by Ultralow Energy Implantation of Phosphorus Ions through a Block Copolymer Thin Film.

In this work, block copolymer lithography and ultralow energy ion implantation are combined to obtain nanovolumes with high concentrations of phosphorus atoms periodically disposed over a macroscopic area in a p-type silicon substrate. The high dose of implanted dopants grants a local amorphization of the silicon substrate. In this condition, phosphorus is activated by solid phase epitaxial regrowth (SPER) of the implanted region with a relatively low temperature thermal treatment preventing diffusion of phosphorus atoms and preserving their spatial localization. Surface morphology of the sample (AFM, SEM), crystallinity of the silicon substrate (UV Raman), and position of the phosphorus atoms (STEM- EDX, ToF-SIMS) are monitored during the process. Electrostatic potential (KPFM) and the conductivity (C-AFM) maps of the sample surface upon dopant activation are compatible with simulated I-V characteristics, suggesting the presence of an array of not ideal but working p-n nanojunctions. The proposed approach paves the way for further investigations on the possibility to modulate the dopant distribution within a silicon substrate at the nanoscale by changing the characteristic dimension of the self-assembled BCP film.

Optically Transparent and Thermally Efficient 2D MoS2 Heaters Integrated with Silicon Microring Resonators

Thermal tuning of the optical refractive index in the waveguides to control light phase accumulation is essential in photonic-integrated systems and applications. In silicon photonics, microheaters are mainly realized by metal wires or highly doped silicon lines, placed at a safe distance (∼1 μm) from the waveguide to avoid considerable optical loss. However, this poses a significant limitation for heating efficiency because of the excessive free-carrier loss when a heater is brought closer to the optical path. In this work, we present a new concept of using optically transparent 2D semiconductors (e.g., MoS2) for realizing highly efficient waveguide-integrated heaters operating at telecom wavelengths. We demonstrate that a single-layer MoS2 heater with negligible optical absorption in the infrared can be placed in close proximity (only 30 nm) to the waveguide and show the best-reported power consumption of Pπ ∼ 7.5 mW for waveguide-integrated heaters (no thermal insulations) without sacrificing the optical insertion loss. The heater’s response time is ∼25 μs, which is limited by the Au/1L-MoS2 Schottky contact. Both the efficiency and response time can be further significantly improved by realizing 2D MoS2 heaters with Ohmic contacts. Our work shows clear advantages of employing 2D semiconductors for heater applications and paves the way for developing novel energy-efficient loss-less 2D heaters for on-chip photonic-integrated circuits.

Improving doped polycrystalline silicon passivating contacts with magnesium fluoride

Improving doped polycrystalline silicon passivating contacts with magnesium fluoride

Improved selectivity and anti-aging ability for 6FDA type carbon molecular sieve membranes by mixing silicon from macro-phase separation to molecule doping

Good gas separation performance and anti-aging ability are important for the applications of carbon molecular sieve membrane (CMSM). In this work, silicon atoms in the form of siloxane-Cl are introduced into 6FDA-DABA type polyimide (PI) precursor membrane, and benzimidazoles (BI) is copolymerized into PI to effectively improve the compatibility between PI and siloxane-Cl. By varying the content of siloxane-Cl, the composite membrane changes from macro-phase separation to molecule level miscibility, which leads to the formation of silicon-rich interface layer and silicon molecule doping after high temperature pyrolysis, respectively. The residual silicon content in CMSM could be as high as 1 wt%. The high content silicon doped CMSM exhibits much improved H2 permeability retention degree (3617 Barrer of H2 permeability, 62% higher) and H2/CH4 selectivity (138, 51% higher) as compared to control CMSM after 45 days of physical aging. This work proves that the incorporation of silicon in CMSMs in proper forms could significantly improve their molecular sieving and anti-aging performances; a higher content of residual silicon and molecule level doping are highly desired. The heteroatom doping is expected to pave a new way for finely tuning the micro-structures of CMSMs and improving gas separation performances.

Introducing Hybrid Defects of Silicon Doping and Oxygen Vacancies into MOF-Derived TiO2-X @Carbon Nanotablets Toward High-Performance Sodium-Ion Storage.

Titanium dioxide (TiO2 ) is a promising anode material for sodium-ion batteries (SIBs), which suffer from the intrinsic sluggish ion transferability and poor conductivity. To overcome these drawbacks, a facile strategy is developed to synergistically engineer the lattice defects (i.e., heteroatom doping and oxygen vacancy generation) and the fine microstructure (i.e., carbon hybridization and porous structure) of TiO2 -based anode, which efficiently enhances the sodium storage performance. Herein, it is successfully realized that the Si-doping into the MIL-125 metal-organic framework structure, which can be easily converted to SiO2 /TiO2-x @C nanotablets by annealing under inert atmosphere. After NaOH etching SiO2 /TiO2-x @C which contains unbonded SiO2 and chemically bonded SiOTi, thus the lattice Si-doped TiO2-x @C (Si-TiO2-x @C) nanotablets with rich Ti3+ /oxygen vacancies and abundant inner pores are developed. When examined as an anode for SIB, the Si-TiO2-x @C exhibits a high sodium storage capacity (285mAhg-1 at 0.2Ag-1 ), excellent long-term cycling, and high-rate performances (190mAhg-1 at 2Ag-1 after 2500 cycles with 95.1% capacity retention). Theoretical calculations indicate that the rich Ti3+ /oxygen vacancies and Si-doping synergistically contribute to a narrowed bandgap and lower sodiation barrier, which thus lead to fast electron/ion transfer coefficients and the predominant pseudocapacitive sodium storage behavior.