kapil bhatt - Academia.edu (original) (raw)

Papers by kapil bhatt

2017 Devices for Integrated Circuit (DevIC), 2017

2017 2nd International Conference for Convergence in Technology (I2CT), 2017

Structurally, an MIM diode is a very thin layer of insulator sandwiched between two metal electro... more Structurally, an MIM diode is a very thin layer of insulator sandwiched between two metal electrodes. Owing to the tunneling based conduction mechanism it facilitates ultra-fast switching speed, desirable for many of the high frequency applications. However, due to thin insulator design considerations and underneath conduction mechanism, they normally do not exhibit diode like behavior. Therefore, the successful implementation of the diode in these applications demands highly non-linear and asymmetric current-voltage characteristics. This necessitates the consideration of design aspects of diode prior to its actual fabrication. In this paper the various design aspects of MIM diode is studied and their influence on the diode's figures of merit is investigated.

SN Applied Sciences, 2021

Present article reports on reduced graphene oxide (rGO) modified poly(3,4-ethylenedioxythiophene)... more Present article reports on reduced graphene oxide (rGO) modified poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) based transparent conducting electrodes for flexible optoelectronic applications. PEDOT: PSS samples embedded with different rGO concentrations i.e. 0, 1, 2, 3, 4, 5 wt% were prepared and later on, bar coated on polyethylene terephthalate substrate using a 30 μm wire size bar. Various parameters including sheet resistance, bending test (outside and inside bending), optical transmittance etc. were estimated. Our analysis indicates that the samples with 1 wt% rGO possess improved results i.e. low sheet resistance (315 ± 8 Ω/sq.) and high transmittance (~ 74%). Additionally, the sample shows low electrical resistance variation up to 12% (maximum increase) during outward bending and 9% (maximum decrease) during inward bending of the sample for bending curvature from 20 to 100 m−1.

Sensors, FETs and chemi resistors are few of the devices which show potential in the area of flex... more Sensors, FETs and chemi resistors are few of the devices which show potential in the area of flexible electronics for health monitoring applications. In the present work, piezoresistive strain sensors based on graphite and graphene on cellulose paper substrate has been reported. Graphite sensor has been fabricated by rubbing pencil on paper and graphene sensor by directly coating graphene ink using paint brush. The resistance of the fabricated sensor increases with outwards bending and vice-versa, further the piezoresistive effect has also been evaluated by applying variable longitudinal stress. A comparative study of gauge factor (GF) depending upon different type of strains has been presented and it has been observed that the GF of graphene piezoresistive strain sensor decreases with increase in number of layers, the GF for graphene sensor is higher as compared to graphite sensor. Fabricated piezoresistive strain sensors may find applications as human body motion detection, gait a...

International Journal of Nanoscience, 2021

In this paper, we report the preparation and characterization of a sensitive and reusable nonenzy... more In this paper, we report the preparation and characterization of a sensitive and reusable nonenzymatic glucose (NEG) sensor based on copper nanowires (CuNWs)/polyaniline (PANI)/reduced graphene oxide (rGO) nanocomposite ink. The CuNWs/PANI/rGO nanocomposite ink was prepared by solvothermal mixing of CuNWs, PANI, rGO and binders. The X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier Transform Infra-Red (FT-IR) spectroscopy techniques were used to assess the structural and morphological parameters of prepared nanocomposite ink. The cyclic voltammetry (CV) technique was used to estimate the electrochemical behavior of prepared NEG sensor. The structural, morphological and spectroscopy results confirmed the change in morphological and oxidation state of CuNWs to CuO nanostructures as a constituent of nanocomposite ink. The CuO nanostructures supported on PANI/rGO demonstrated good electrochemical stability and great electrocatalytic activity toward gl...

Applied Physics A, 2020

The present work focuses on the preparation and characterizations of a highly sensitive, reusable... more The present work focuses on the preparation and characterizations of a highly sensitive, reusable, linear, anti-interferent, and low-cost Cu+2/polyaniline (PANI)/reduced graphene oxide (rGO) nanocomposite ink-based non-enzymatic glucose (NEG) sensor. The synergistic properties of Cu+2/PANI and rGO result in a large number of electrochemically active and stable sites which catalytically favored the glucose oxidation. The crystal structure and morphology of PANI, Cu+2/PANI composite, and Cu+2/PANI/rGO nanocomposite ink encouraged the usefulness of Cu+2/PANI/rGO nanocomposite ink as an electrocatalyst in NEG detection. A NEG sensor was prepared by drop coating Cu+2/PANI/rGO nanocomposite ink on a low-cost patterned FR4 electrode. The cyclic voltammetry and chronoamperometry tests were performed to estimate the electrochemical behavior of prepared Cu+2/PANI/rGO/FR4 NEG sensor. The electrooxidation of glucose was achieved at an applied potential of 0.66 V. An anti-interferent Cu+2/PANI/rGO/FR4 NEG sensor demonstrated a linear response in two different glucose concentration regimes 2.8–22.2 µM and 0–4 mM with current sensitivity of 4168.37 μA mM−1 cm−2 and 525.4 μA mM−1 cm−2, respectively. The prepared sensor displayed a limit of detection (LOD) of 4.93 µM with a response time of < 5 s. The excellent performance parameters of the Cu+2/PANI/rGO/FR4 NEG sensor recommend its relevance in human serum samples. These values of operating voltage, current sensitivity, linear range, LOD and anti-interference ability promise its usefulness in practical applications.

2017 International Conference on Inventive Communication and Computational Technologies (ICICCT), 2017

International Journal of Nanoparticles, 2018

The metal-insulator-metal (MIM) diodes are considered very promising for high frequency applicati... more The metal-insulator-metal (MIM) diodes are considered very promising for high frequency applications because of its tunnelling-based ultrafast charge transport mechanism. A wide variety of materials are being explored in quest of developing these thin film devices. Recently, organic insulator-based MIM diodes have attracted significant attention to the researchers due to its several advantages and have become a promising alternative of conventional inorganic insulators. In the present work the feasibility of an organic polymer polymethyl methacrylate (PMMA) is investigated for insulating material of MIM junction. It is a transparent resin which is able to produce uniform and thin insulating layer with low defect density. In this work, an Al/PMMA/Cr structure is fabricated by optimising different process parameters in order to develop high performance, reproducible organic MIM diodes. The as fabricated device exhibited fairly asymmetric and nonlinear current-voltage characteristics, which reveals the viability of PMMA as candidate material for insulator layer in MIM diodes.

Advanced Engineering Materials, 2019

Journal of Nanoscience and Nanotechnology, 2020

Metal-Insulator-Metal (MIM) diodes used for infrared detection and frequency mixing since many de... more Metal-Insulator-Metal (MIM) diodes used for infrared detection and frequency mixing since many decades and their development for energy harvesting applications in rectenna solar cell has accelerated a decade ago. In the horizon of these applications less complex fabrication methodology, accurate simulation methods and optimum material combination are required. Ultra-fast response of MIM diodes makes them a potential candidate for solar energy harvesting applications. Here in this work, the design and fabrication issues of MIM diode from simulation methodology based on insulating thickness properties to the fabrication methodology are discussed. MIM diode for Al–Al2O3–Ag combination is fabricated and characteristics such as I(V), asymmetry and non-linearity are reported.

IEEE Antennas and Wireless Propagation Letters, 2019

In this letter, highly efficient dual-band rectenna at 2.4 and 5.8 GHz for energy harvesting is p... more In this letter, highly efficient dual-band rectenna at 2.4 and 5.8 GHz for energy harvesting is presented. A new sickle-shaped antenna is designed to operate at both frequencies. Rectenna shows the maximum RF–DC conversion efficiency of 63% and 54.8% at 2.4 and 5.8 GHz, respectively. The impact of matching network and output filter on RF–DC conversion efficiency at both frequencies is analyzed. The output dc voltage of 3 and 2.6 V is measured for 2.4 and 5.8 GHz correspondingly at a 600 Ω load resistance. The rectenna can be utilized for various low-power applications.

Opto-Electronics Review, 2018

Abstract Transparent Conductive Electrode (TCE) is an essential part of the optoelectronic and di... more Abstract Transparent Conductive Electrode (TCE) is an essential part of the optoelectronic and display devices such as Liquid Crystal Displays (LCDs), Solar Cells, Light Emitting Diodes (LEDs), Organic Light Emitting Diodes (OLEDs) and touch screens. Indium Tin Oxide (ITO) is a commonly used TCE in these devices because of its high transparency and low sheet resistance. However, scarcity of indium and brittle nature of ITO limit its use in future flexible electronics. In order to develop flexible optoelectronic devices with improved performance, there is a requirement of replacing the ITO with a better alternate TCE. In this work, several alternative TCEs including transparent conductive oxides, carbon nanotubes, conducting polymers, metal nanowires, graphene and composites of these materials are studied with their properties such as sheet resistance, transparency and flexibility. The advantage and current challenges of these materials are also presented in this work.

Terahertz Spectroscopy - A Cutting Edge Technology, 2017

Advanced Science Letters, 2015

The accurate modeling of Transport characteristics is important for prediction of current–voltage... more The accurate modeling of Transport characteristics is important for prediction of current–voltage characteristics of Metal-Insulator-Metal (MIM) diode for THz energy harvesting applications. In the present paper, Nb/Nb2O5/Ta2O5/Nb, MIIM structure has been evaluated using WKB and TMM models for estimating the transport probability and current density. The total insulator thickness has been varied from 6–10 nm to evaluate the diode like behavior. Also, a review of different modeling methods used for determining the transport probability has been presented. The TMM model has been observed to result more realistic I–V characteristics, moreover the accurate modeling of MIM diodes requires an alternative model like Non-equilibrium green’s function (NEGF) approximations as it can be correlated with Metal-Insulator-Semiconductor (MIS) structure in nanoscale FET devices.

Indian Journal of Pure & Applied Physics, 2015

The wireless power transmission (WPT) technology is an extension of wireless communication. The p... more The wireless power transmission (WPT) technology is an extension of wireless communication. The physics of WPT and wireless communication are related, but WPT is distinct from wireless transmission for transferring information (such as radio and mobile phones etc.), where the percentage of the power that is received is only important if it becomes too low to successfully recover the signal. With WPT, the efficiency is a more critical parameter and this creates important differences in these technologies. This paper presents the wireless power transmission (WPT), from past work to most recent accomplishments including recent developments, potential approaches and factors responsible for designing most critical rectifying diodes operating at terahertz/petahertz frequencies.

Optik

Abstract Transparent conducting electrodes (TCEs) are key components in optoelectronic devices. T... more Abstract Transparent conducting electrodes (TCEs) are key components in optoelectronic devices. The commonly used materials for this purpose are indium tin oxide (ITO) and fluorine-doped indium tin oxide (FTO). However, they have limited application for flexible optoelectronic devices due to their brittleness nature. Among various alternatives of TCE materials, graphene has been considered as a good choice owing to its extraordinary properties, such as excellent optical transparency, electrical conductivity mechanical strength along with layer stability on various substrates. In the present work, few-layer graphene (FLG) films have been deposited on flexible polyethylene terephthalate (PET) sheets by rubbing technique at room temperature. The prepared samples were characterized using Optical transparency, Raman spectroscopy, Atomic force microscopy, bending test, and sheet resistance measurements to optimize rubbing parameters. The fabricated FLG films on PET substrate exhibited a sheet resistance 400 Ω/sq. with transmittance ∼60 % indicating its promising application as a flexible transparent conducting electrode in optoelectronic devices.

AEU - International Journal of Electronics and Communications