Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Department of Physics

VIT Unitversity

School of Advanced Sciences

Vellore Campus

Department of Software Systems

School of Computer Science and Engineering

2019 International Conference on Vision Towards Emerging Trends in Communication and Networking (ViTECoN)

Crop Shop – An application to maximize profit for farmers

Iron (Fe)-doped indium tin oxide thin films (In 0.95 − x Fe x Sn 0.05 ) 2 O 3 at x = 0.00, 0.05, 0.10, and 0.15 were deposited onto glass substrates using an electron beam evaporation technique. The coated thin films were characterized by X-ray diffractometer (XRD), UV-VIS-NIR spectrophotometer, photoluminescence spectrophotometer, scanning electron microscope, and vibrating sample magnetometer to study their structural, optical, morphological, and magnetic properties, respectively. The crystallite size of the films increased from 18 to 30 nm with Fe concentration (x). The morphology showed the formation of nanorods. The bandgap of the films decreased from 3.94 to 3.81 eV. The X-ray photoelectron spectroscopy (XPS) studies confirm the presence of Fe ions in two different oxidation states (Fe 2+ , Fe 3+ ). The magnetic studies revealed the paramagnetic behavior of the films at room temperature and at low temperature (5 K). The effective magnetic moment (μ eff ) of Fe-doped indium tin oxide thin films was calculated using Langevin theory of paramagnetism extending to Curie’s law. The effective magnetic moment (μ eff ) was increased on increasing the dopant concentration. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Journal of Superconductivity and Novel Magnetism

No Signature of Room Temperature Ferromagnetism in Fe-Doped ITO Thin Films

Circular patch antenna for frequency reconfigurable and polarization switching in the antenna using feed configuration is presented. On varying capacitance of the varactor diode from 2.67pF to 0.99pF the antenna tuned from 1.85 to 2.55 GHz impedance bandwidth (32%). The cascaded branch line coupler (BLC) with switching feed configuration is used to achieve polarization reconfiguration (i.e.) vertical linear (VL)/horizontal linear (HL) polarization, RHCP, LHCP in the antenna. The proposed feed network is used to control tunable over a wideband from 1.5 to 3 GHz. The impedance bandwidth of patch antenna is matched with the impedance bandwidth of cascaded BLC feed network to achieve all the performance. © 2019 IEEE.

Department of Communication Engineering

School of Electronics Engineering

Circular Patch Frequency Tunable Antenna with Switching Polarization Feed Configuration

Computer Science

Chennai Campus

World University root node

Materials Research Innovations

Synthesis, growth and broadband dielectric characterization of nonlinear optical single crystal: 4-methylpyridinium5-sulfosalicylate

Single crystals of potassium pentaborate dihydrate KB5H4O10. 2H2O (KBH) of dimension (10 × 5 × 2 mm3) were successfully grown through the solution growth technique under slow evaporation condition. The crystal structure of potassium pentaborate dihydrate was determined by single crystal X-ray diffraction and the material was crystallized in the orthorhombic system with space group Aba2 with lattice parameters a = 11.13 (Å), b = 11.23 (Å), c = 9.10 (Å), α = β = γ = 90°, volume = 1137 (Å)3. The presence of BO3, BO4 and water molecules were confirmed using Fourier transform infrared (FT-IR) vibrational spectroscopy. The ultraviolet (UV) - visible spectrum reveal the optical and electronic transition properties of the grown crystal. The optical absorption edge of the grown crystal is 210 nm with energy gap of 4.96 eV. The thermogravimetric (TG) and differential scanning calorimetry (DSC) studies showed that the material was stable up to 106 °C, which indicated that the grown crystal could be effectively used for various device applications below the temperature. Vickers microhardness is performed on the grown crystal in the load range from 10 to 50 g. The variation of hardness number with load represents the normal indentation size effect. Mechanical parameters such as yield strength, elastic stiffness constant, fracture toughness, brittleness index and crack propagation of single crystal are discussed in detail. The dielectric behaviour of the single crystal over an extensive range of frequencies and temperature is described. The second harmonic generation (SHG) signal from the KBH crystal is found to be 1.23 mV. © 2018

Materials Chemistry and Physics

Investigation on the growth, optical, mechanical and dielectric properties of an inorganic potassium pentaborate dihydrate (KB5H4O10.2H2O) single crystal

In this present study, we have discussed about the synthesis of spinel type ZnCo2O4 by sol-gel combustion method using glycine as a chelating agent. Structural and morphological verifications are carried out using XRD, SEM and the functional group confirmation by using FT-IR. The temperature dependent dielectric relaxation and conduction mechanism have been analyzed by using dielectric measurements, impedance spectroscopy and electric modulus studies in the frequency range of 50 Hz to 5 MHz between the temperatures 303 K and 593 K. Influence of oxygen vacancy on the behaviour of dielectric relaxation is due to the hopping mechanism between Co2+ and Co3+ sites due to the structural defect in the material. XPS measurement confirms the different oxidation state in Co-site and the existence of oxygen vacancy in the material. The conductivity of the material is studied with Jonscher Power law. © 2018 Elsevier B.V.

Journal of Non-Crystalline Solids

Structural and electrical properties of ZnCo2O4 spinel synthesized by sol-gel combustion method

Journal of Materials Science: Materials in Electronics

Crystal growth, A.C. electrical and nonlinear optical studies of pure and dl-methionine doped ammonium dihydrogen phosphate single crystals

The metal oxide semiconductors (ZnO, SnO 2 , Al 2 O 3 and TiO 2 ) were synthesized by co-precipitation method. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and UV-Visible spectrometer in diffused reflectance (DR) mode. The XRD results stipulated that the ZnO nanoparticle is crystallized in hexagonal wurtzite structure, SnO 2 nanoparticles in rutile tetragonal structure, Al 2 O 3 nanoparticle in rombohedral structure and TiO 2 nanoparticle in rutile anatase structure. The SEM investigation affirms that all the synthesized nanopowders are composed of uniformly distributed grains. The UV-Vis spectrum proclaimed that the synthesized nanoparticles having the band gap of 3.2 eV (ZnO), 3.3 eV (SnO 2 ) and 3.5 eV (TiO 2 ) respectively. The synthesized nanoparticles were replaced with small cladding region of the optical fiber and act as a temperature sensing materials. The temperature sensing characteristics of the synthesized nanoparticles were investigated for broad wavelength range (200-1000 nm). It reveals that the synthesized Al 2 O 3 nanoparticles were given linear and high sensitivity (~27) at 697 nm compared with other sensing materials. Further, we have studied the wavelength dependent temperature sensing characteristics of Al 2 O 3 nanopowders and it show better sensitivity (~34) in blue wavelength region (450 nm-495 nm). © 2019 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Nanoscience and Nanotechnology (ICNAN'16)

Department of Sensor and Biomedical Technology

Materials Today: Proceedings

Fabrication of Fiber Optic Based Temperature Sensor

We propose a sixfold photonic quasi-crystal fiber with a trapezoidal analyte channel based on surface plasmon resonance for the detection of high-refractive-index (RI) liquid analytes and numerically analyze its sensing performance for different liquid analyte refractive indices and heights using the finite-element method. In contrast to the common D-shaped structure photonic crystal fiber, we design a trapezoidal analyte channel to investigate the role of the sample liquid height within the channel and discussed the feasibility of the fabrication process. We find that with various liquid analyte heights ratios of 20%, 25%, 30%, and 50% of the maximum channel height, the proposed biosensor exhibits linear sensing performance with a maximum RI sensitivity of 4400, 6100, 8000, and 17000 nm/RIU, respectively, for analytes RI range of 1.44-1.57, 1.41-1.51, 1.40-1.49, and 1.40-1.44. This sensor is suitable to detect various high RI chemicals, biochemicals, and organic chemical samples. Owing to its simple structure of the proposed biosensor with promising linear sensing performance, we envisage that this biosensor could turn out to be a versatile and competitive instrument for the detection of high-RI liquid analytes. © 1995-2012 IEEE.

Fulltext

IEEE Journal of Selected Topics in Quantum Electronics

Design and Analysis of Surface-Plasmon-Resonance-Based Photonic Quasi-Crystal Fiber Biosensor for High-Refractive-Index Liquid Analytes

We report an analysis of p-Cu(In,Ga)Se2/n-ZnMgO solar cell through solar cell capacitance simulator. The cell performance has been studied as a function of absorber and buffer layer parameters like thickness, carrier concentrations, mid-gap and interface defect density, sheet resistance and shunt resistance. The efficiency and fill factor of the optimized cell is found to be 21.93% and 81.65% respectively. The optimized device does not exhibit J–V distortion behavior which is common in CIGS-based solar cells. A few device models with donor interface defects, acceptor interface defects and high conduction band offset are proposed, such that cell efficiency is not compromised, but was able to reproduce the experimentally observed J–V distortion behavior in CIGS cell with ZnMgO buffer layer. These proposed cells have been simulated and analyzed for the dark–light J–V crossover and J–V red-kink behavior in detail. The observed J–V distortion behavior is attributed to the reduction in the effective doping of buffer layer which results in increasing acceptor-type mid-gap defect density, persistent photo conductivity of buffer layer and high value of conduction band offset. Dark–light J–V crossover is explained by change in secondary barrier height at the interface between the absorber and buffer layers. Red-kink behavior is due to the lack of free electrons in the buffer layer where these electrons are trapped into acceptor-type mid-gap defect under red-light illumination. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Applied Physics A: Materials Science and Processing

One-dimensional modeling for an investigation into parameter optimization, crossover and red-kink behavior of ZnMgO buffer layer Cd-free Cu(In,Ga)Se2 solar cell