Tuning the permittivity of tellurium dioxide by Ti substitution

Keerthana,; Rao, Vishal Govind; Venimadhav, A.

doi:10.1016/j.ceramint.2019.12.126

Cited by 4 publications

(4 citation statements)

References 19 publications

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“…The dielectric constants of the single crystal α-TeO 2 were measured in a previous study to be 22.9 and 24.7 in the x and y directions, respectively . The dielectric constant of 20 was also measured for the crystalline α-TeO 2 over the frequency range from 400 Hz to 1 MHz . The experimentally determined dielectric constants of crystal and powder α-TeO 2 are on the same order of magnitude with the computed dielectric constant of α-TeO 2 with an oxygen vacancy.…”

Section: Resultsmentioning

confidence: 56%

Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO₂

Nguyen,

Macaluso,

Huda

2024

J. Phys. Chem. C

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Tellurite glasses have emerged as a promising candidate for nonlinear optics (NLO) due to their high refractive index and third-order optical susceptibility (χ 3 ). In this work, we focus on the electronic structure of crystalline TeO 2 , a precursor to numerous TeO 2 -based glasses. All three crystalline TeO 2 polymorphs are wide-gap semiconductors and have electronic contributions from the Te 4+ 5s 2 lone pairs near the Fermi level, which affect optical properties. Based on the formation energies, the formation of oxygen vacancies is strongly favorable during synthesis. Introduction of an oxygen vacancy induces notable changes in the chemical environment in the pristine α-TeO 2 structure and the response of the Te 5s 2 lone pairs. Comparative analysis to the measured refractive indices and static dielectric constant (a second-rank tensor) shows that the calculated values of α-TeO 2 with the presence of an oxygen vacancy (α-TeO 2 :O v ) agree well with experimental data. The high distortion index and stereochemical activity ratio of α-TeO 2 :O v contribute to its polarizable asymmetric electron density. High polarization and faster orientation of the dipoles in α-TeO 2 with the presence of an oxygen vacancy make it an excellent NLO material for ultrafast optical switch applications. This study can help to guide design principles and improve our understanding of the electronic origin of NLO materials containing lone pairs.

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Section: Resultsmentioning

confidence: 56%

Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO₂

Nguyen,

Macaluso,

Huda

2024

J. Phys. Chem. C

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“…These works reveal exceptionally unique properties like high carrier mobility, high luminescent nature, dynamic and thermal stability annotating it as a promising material for power electronic, opto-electronic and photonic applications [16]. Meanwhile irrespective of its form, TeO 2 exhibits a wide band gap (bandgap ~3.8-4.7 eV) with high dielectric constant (k ~19-23) and its dielectric nature is lesser explored but seems to be of great resourcefulness towards futuristic devices [17,18]. In this light of possibility, we realize, it can be a potential RS material.…”

Section: Introductionmentioning

confidence: 99%

Formation-free resistive switching in nanocrystalline tellurium oxide

Keerthana,

Venimadhav

2024

Nanotechnology

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In this work, we report on the observation of resistive switching in the nanocrystalline Tellurium oxide (TeOx) in ITO/TeOx/Ag device configuration. The TeOx films grown in an O2/Ar environment have dominant β-TeO2 along with other polymorphs and amorphous TeO2. From the resistive switching characteristics, it is suggestive that the β-TeO2 phase promotes the conductive filament formation across the highly insulating amorphous matrix. The memory device demonstrates bipolar resistive switching with excellent endurance, retention and on-off ratio. The device also features formation-free switching with low set and reset voltage (0.6 V and -0.8 V respectively) and displays multilevel switching upon varying compliance current. I-V characterization clarifies the conduction path is indeed filamentary type. The result highlights that TeOx can be a prominent resistive switching material for memory and brain-inspired computing devices.

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“…[16] Both amorphous and crystalline forms of TeO 2 display a dielectric constant in the range of 19-25; however, until now it has not been considerably harnessed for high-k applications. [17] Dielectric is an essential functional layer in the field effect devices and the primary criteria for high-k materials are to have a dielectric constant greater than 10 (preferably in the range of [20][21][22][23][24][25][26][27][28][29][30] and bandgap over 4 eV (considering 1 eV offset between semiconductor and dielectric with respect to valence and conduction bands). [18] Binary oxides turn out to be the prime choice due to their simplicity and completry metal oxide semiconductor (CMOS) compatibility; however, low processing temperature and ease of fabrication are also to be considered.…”

Section: Introductionmentioning

confidence: 99%

“…[ 16 ] Both amorphous and crystalline forms of TeO 2 display a dielectric constant in the range of 19–25; however, until now it has not been considerably harnessed for high‐ k applications. [ 17 ]…”

Section: Introductionmentioning

confidence: 99%

TeO₂: A Prospective High‐k Dielectric

Keerthana,

Venimadhav

2023

Physica Rapid Research Ltrs

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Herein, high‐k dielectric behavior of TeO2 thin films is investigated. The films are prepared using pulsed laser deposition on indium tin oxide (ITO)–glass substrates. Increasing the growth temperature has improved the surface roughness, transparency, and bandgap of the films. Films grown at 500 °C display nanocrystalline nature which is reflected in the increase of bandgap to 4.7 eV and is higher than the bulk value of α‐TeO2 (3.7 eV). The nanocrystalline TeO2 films in the metal–insulator–metal configuration show a stable high permittivity of ≈19 with low leakage current (J < 1 × 10−7 A cm−2) and good voltage stability (α = 509 ppm V−2). Field‐effect modulation is observed in the metal–oxide–semiconductor stack configuration with tellurium as a semiconductor. The study suggests nanocrystalline TeO2 as a low‐temperature processable high‐k material with high transparency for transistor applications.

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Tuning the permittivity of tellurium dioxide by Ti substitution

Cited by 4 publications

References 19 publications

Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO₂

Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO₂

Formation-free resistive switching in nanocrystalline tellurium oxide

TeO₂: A Prospective High‐k Dielectric

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Tuning the permittivity of tellurium dioxide by Ti substitution

Cited by 4 publications

References 19 publications

Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO2

Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO2

Formation-free resistive switching in nanocrystalline tellurium oxide

TeO2: A Prospective High‐k Dielectric

Contact Info

Product

Resources

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Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO₂

Stereochemically Active Lone Pairs: Unraveling the Electronic Origin of Dielectric Response in Nonlinear Optical TeO₂

TeO₂: A Prospective High‐k Dielectric