Vivek Garg
@svnit.ac.in
Assistant Professor, Department of Electronics Engineering
S. V. National Institute of Technology Surat
EDUCATION
Indian Institute of Technology (IIT) Indore
RESEARCH, TEACHING, or OTHER INTERESTS
Electrical and Electronic Engineering, Renewable Energy, Sustainability and the Environment, Condensed Matter Physics, Electrochemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Hitarth Narsi Patel, Rajesh Kumar Sharma, Deepak Joshi, and Vivek Garg
Elsevier BV
Hitarth N. Patel, Rajesh K. Sharma, Deepak Joshi, and Vivek Garg
Wiley
Cu2BaSnS4−xSex (CBTSSe) has recently attracted substantial attention as an emerging chalcogenide material due to its abundant constituent elements and reduced antisite disorders compared to the Cu2ZnSn(S,Se)4 (CZTSSe). In this work, recently reported Mo/CBTSSe/Cd:ZnS Zn1−xCdxS/i‐Mg:ZnO (ZMO)/Al:ZnO (AZO) cell structure with the power conversion efficiency (PCE) of 6.17% is used to develop the baseline model. Afterwards, device performance parameters are fine‐tuned by investigating the effect of (a) absorber thickness and defect density, (b) absorber/buffer conduction band offset, (c) absorber/buffer interface defect density, (d) anti‐reflection coating at the front layer, and (e) back contact optimization. The device with the optimized parameter values of absorber thickness: 1.2 μm, absorber defect density: 1015 cm−3, and alternate buffer layer of WS2, interface defect density:1010 cm−2, resulting in the PCE of 12.94%. Introducing an anti‐reflective coating (ARC) at the front contact further improves the PCE to 17.87%. Finally, introducing Ni as a back contact instead of Mo enhances the PCE to 20.70%. These results provide insight into possible techniques to improve the performance of CBTSSe‐based solar cells.
Ashish Kumar Yadav, Shreevathsa N S, Rohit Singh, Partha Pratim Das, Vivek Garg, and Sushil Kumar Pandey
Institute of Electrical and Electronics Engineers (IEEE)
Using density functional theory calculations, we demonstrate the quantum capacitance of the VS2 electrode which can be improved by doping with non-metallic elements such as nitrogen (N), phosphorus (P), and arsenic (As) atoms. The radius, charge, and morphology of these non-metallic elements help to improve the performance of VS2 material as electrodes of supercapacitors. The As-doped VS2 monolayer demonstrated the maximum quantum capacitance of 31.2369 μF/cm2 at 300 K. At 1200 K, quantum capacitance reaches the value of 25.2149 μF/cm2, showing the inconsiderable change in value for this wide range of temperature variation. Additionally, the other important properties of undoped and doped VS2 monolayers such as density of states, energy band structure, electrical conductivity, thermal conductivity, and the Seebeck coefficient were also computed and examined in detail. The band structure of the P and As-doped VS2 monolayers showed a metallic nature, which is suitable for electrode application. In the case of As-doped VS2 material, a high figure of merit of 3.536 was observed by using DFT-D2 calculations, due to the large Seebeck coefficient and significant electrical conductivity. Our findings will be helpful in further exploring the suitability of VS2 monolayers as electrodes of supercapacitors.
Rajesh K. Sharma, Hitarth N. Patel, Vivek Garg, and Shivendra Yadav
Wiley
This article comprehensively investigates the photovoltaic performance of a 3% GeI2‐doped ASnI2Br absorber in a solar cell. The cell features an inverted structure (fluorine‐doped tin oxide [FTO]/poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate [PEDOT:PSS]/absorber/C60/Ag) and utilizes EDA0.01(GA0.06(FA0.8Cs0.2)0.94)0.98 as the A‐site cation (EDA for ethylenediamine; GA for guanidinium; FA for formamidinium). Through systematic numerical simulation and optimization, the photovoltaic performance of the solar cell is enhanced by sequentially optimizing several parameters: 1) absorber thickness and defect density, 2) conduction band offset at the ASnI2Br/C60 interface, doping of the electron‐transport layer (ETL), and its interface with the absorber, and 3) valence band offset at the PEDOT:PSS/ASnI2Br interface, and doping of the hole‐transport layer and its interface with the absorber. Additionally, the impact of series resistance (Rs) variation on device performance is investigated. Starting with an initial power conversion efficiency (PCE) of 4.86%, the systematic numerical optimization process elevates it to an impressive 18.55%. Furthermore, a final cell structure is proposed where C60 is replaced with indium‐doped tin oxide (ITO) as the ETL layer. This optimized FTO/PEDOT:PSS/absorber/ITO structure demonstrates a remarkable PCE of 18.68%. These findings hold significant promise for advancing tin‐perovskite solar cell technology.
Akash Jadhav, Shivendra Yadav, Sushil K Pandey, Vivek Garg, and Praveen Dwivedi
IOP Publishing
Abstract In this paper, Dielectrically Modulated (DM) pocket Tunnel Field Effect Transistor (TFET) and Accumulation Mode Field Effect Transistor (AMFET) biosensors are examined for the Sensitivity estimation of different thicknesses of biotarget (Streptavidin)/bioreceptor (Biotin)/silica binding protein (SBP or APTES) biomolecules with a fully filled and partially filled cavity. The sensitivity parameter is based on realistic process detection and is calculated as the ratio of biotarget to bioreceptor drain current for neutral and charged biomolecules. The effect on the sensitivity for a filled cavity is observed for: a) varying the thickness of streptavidin and Biotin for fixed SBP (APTES) thickness, b) varying the thickness of streptavidin and APTES for fixed biotin thickness, for both Pocket TFET and AMFET. The maximum sensitivity is observed in 4 nm thick streptavidin for the front gate voltage V fg: −3.8 V and V fg: −1.6 V for pocket TFET and AMFET, respectively.
Bikash Bhandari, Ashish Kumar Yadav, Rohit Singh, G. Kiran, Amit Kumar Singh, Vivek Garg, and Sushil Kumar Pandey
Wiley
The gallium antimonide (GaSb) material has very attractive electronic and optoelectronic properties which are suitable for next‐generation infrared (IR) photodetector applications. In this work, properties of undoped GaSb material such as density of states, bandstructure, electron density, absorption coefficient, dielectric function, refractive index, and extinction coefficient are calculated using density‐functional theory (DFT). Moreover, the effects of doping with Ge, Sn, and Zn elements on these properties of GaSb material are investigated. It is found that undoped GaSb material exhibits a direct gap of ≈0.72 eV. Among different doping elements, Ge‐doped GaSb produces a very significant enhancement in optical properties. The Ge‐doped GaSb demonstrates a four times higher absorption coefficient in comparison to undoped GaSb in the IR region at 0.8 eV photon energy. GaSb‐based photodetector device is designed using the Solar Cell Capacitance Simulator (SCAPS) 1D tool. The efficiency of the designed photodetector with optimum thicknesses and doping of different layers is found to be improved from 21.34% to 25.91% after incorporating the absorption data set obtained from the DFT calculations. Additionally, the photodetector with optimum parameters demonstrates maximum responsivity of value ≈0.31 A W−1. In the previous findings, it is demonstrated that GaSb is a very suitable material for next‐generation IR photodetector applications.
Sarita Manjhi, Gaurav Siddharth, Sushil K. Pandey, Brajendra S. Sengar, Praveen Dwivedi, and Vivek Garg
Institute of Electrical and Electronics Engineers (IEEE)
Indoor photovoltaics (IPVs) have piqued the interest of many because of their potential to power small and portable electronics and photonic devices. This work investigates one of the exemplary perovskite inspired materials (PIMs), bismuth oxy-iodide (BiOI). In order to explore the potential of BiOI in the indoor environment, the baseline model of BiOI device [indium tin oxide (ITO)/NiOx/BiOI/ZnO/Contact] is developed using the experimental results of a recent study with a power conversion efficiency (PCE) of 4%. The performance of the proposed device is fine-tuned by investigating the effect of: 1) absorber thickness and defect density and 2) valence band offset (VBO) between the hole transport layer (HTL) and absorber interface (NiOx/BiOI) along with the interface defect density. Furthermore, the series and shunt resistance of the device is optimized. Additionally, the performance of the optimized device is investigated under different WLED light intensities. Finally, after optimizing the device under WLED illumination, the best performance parameters achieved are ${J} _{\\text {sc}}$ : 1.83 mA/cm2, ${V} _{\\text {oc}}$ : 1.33 V, FF: 85.91%, and PCE: 40%. Moreover, the optimized device performance under different indoor light sources: WLED, halogen, and compact fluorescent lamps (CFLs), has been performed to estimate the performance under widely utilized lighting sources.
V P Vinturaj, Ashish Kumar Yadav, T K Jasil, G Kiran, Rohit Singh, Amit Kumar Singh, Vivek Garg, and Sushil Kumar Pandey
Springer Science and Business Media LLC
Kumari Prajakta, V. P. Vinturaj, Rohit Singh, Vivek Garg, Saurabh Kumar Pandey, and Sushil Kumar Pandey
Wiley
Herein, the comprehensive study of different properties of undoped MoS2, MoS2 lattice with sulfur (S) and, molybdenum (Mo) vacancy, and MoS2 with substitutional doping of niobium (Nb), vanadium (V), and zinc (Zn) atoms is done. The density functional theory (DFT) is used and the electronic properties like density of states, band structure, electron density, and optical properties like dielectric function, optical conductivity, and refractive index are studied. It is observed that undoped MoS2 monolayer shows direct bandgap semiconductor characteristics with a bandgap of around 1.79 eV. P‐type characteristics are observed for Nb‐, V‐, and Zn‐doped MoS2 lattices. The real part and imaginary parts of all optical parameters along x and z directions for different MoS2 supercells are found to be anisotropic in nature up to a photon energy of almost 11 eV and thereafter they show nearly isotropic nature. Finally, it is found that the obtained properties of MoS2 monolayer as per literature are suitable for next‐generation MOSFET application.
Deepak Singh, Brajendra S. Sengar, Praveen Dwivedi, and Vivek Garg
Elsevier BV
Ashish Kumar Yadav, Chandrabhan Patel, G. Kiran, Rohit Singh, Amit Kumar Singh, Vivek Garg, Shaibal Mukherjee, and Sushil Kumar Pandey
Springer Science and Business Media LLC
Shivendra Yadav, Adarsh Singh Niranjan, and Vivek Garg
Springer Science and Business Media LLC
Shivendra Yadav, Mohammad Aslam, Vivek Garg, and Pallerla Joseph Ritesh Reddy
Springer Science and Business Media LLC
Sushil Kumar Pandey, Vivek Garg, Nezhueyotl Izquierdo, and Amitesh Kumar
CRC Press
Sachchidanand, Vivek Garg, Anil Kumar, and Pankaj Sharma
Elsevier BV
Vivek Garg, Brajendra S. Sengar, Gaurav Siddharth, Shailendra Kumar, Victor V. Atuchin, and Shaibal Mukherjee
Elsevier BV
Sachchidanand, Vivek Garg, Anil Kumar, and Pankaj Sharma
IEEE
The proposed lead-free Cs3Sb2Br9 (Cesium Antimony Bromide) perovskite is newly discovered material with numerous beneficial optoelectronics properties and nontoxic. While this proposed perovskite used in optoelectronics applications before. For the first time, we proposed Cs3Sb2Br9 as an absorber within a solar cell device. With its optimized parameters, our proposed perovskite solar cell (PSC) achieved an impressive power conversion efficiency (PCE) of 12.88% having open-circuit voltage (VOC) of 2.07 V, short-circuit current density (JSC) of 7.01 mA/cm2, and fill factor (FF) of 88.63% which is considerable performance of Cs3Sb2Br9 PSC in comparison to other reported Cs based PSCs in the study.
Brajendra S. Sengar, Vivek Garg, Gaurav Siddharth, Amitesh Kumar, Sushil Kumar Pandey, Mayank Dubey, Victor V. Atuchin, Shailendra Kumar, and Shaibal Mukherjee
Institute of Electrical and Electronics Engineers (IEEE)
Back-contact modification using a 10-nm ZnS layer in CZTSSe-based solar cell can play a crucial role in improving photovoltaic conversion efficiency. An ultrathin layer of ZnS is deposited over Mo-coated soda lime glass substrate before depositing CZTSSe using sputtering. The crystal structure of deposited CZTSSe thin films over ZnS is recognized as (112)-oriented, polycrystalline in nature, and free from the presence of any secondary phases such as Cu2(S,Se) or Zn(S,Se). The bandgap of CZTSSe thin films deposited over ultrathin ZnS is observed to increase from 1.49 (deposited over Mo directly) to 1.58 eV at room temperature, as determined by spectroscopic ellipsometry. In addition, numerical simulation has been performed using SCAPS software. The impact of ZnS layer has been simulated by using the defects in the absorber and at the interface of ZnS/CZTSSe. The simulated results have been validated with experimentally fabricated CZTSSe device. Simulated device with ZnS intermediate layer is observed to give rise to a photovoltaic conversion efficiency of 15.2%.
Brajendra S. Sengar, Vivek Garg, Amitesh Kumar, and Praveen Dwivedi
Institute of Electrical and Electronics Engineers (IEEE)
Perovskite-based solar cells with planar configuration have been perceived as an alternative and attractive option for photovoltaic technology due to high power conversion efficiency (PCE). The performance of heterojunction-based devices is hindered by the recombination in the perovskite layers. The homojunction is suitable for further improvement in PCE due to the built-in electric field, which will enhance the transport of photogenerated charge carriers, therefore, reducing recombination losses. A detailed analysis of the homojunction-based device is needed for further improvement in PCE. In this study, the planar homojunction perovskite photovoltaic device has been simulated by solar cell capacitance simulator (SCAPS). Simulation analysis shows the dependence of PCE on the thickness and defects of the perovskite layer. Recombination analysis at the different junctions has been simulated using hypothetical interface layers at the respective junctions. It has been revealed that the interface defects influence the device performance. The proposed MAPbI3 homojunction-based devices have achieved more than 23% PCE, which is significantly higher than the existing planar heterojunction-based devices.
Praveen Dwivedi, Rohit Singh, Brajendra Singh Sengar, Amitesh Kumar, and Vivek Garg
Institute of Electrical and Electronics Engineers (IEEE)
In this work, a new simulation approach of transient analysis on single cavity dielectric-modulated (DM) <inline-formula> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula>-type of tunnel field-effect transistor (TFET) is examined for biosensing applications. The device operation and performance are investigated using the 2D device simulator and results are well-calibrated with experimental data. In this work, we have examined DC transfer characteristics, the transient response of drain current, drain current sensitivity (<inline-formula> <tex-math notation="LaTeX">${S}$ </tex-math></inline-formula>), and selectivity (<inline-formula> <tex-math notation="LaTeX">$\\Delta {S}$ </tex-math></inline-formula>). Focussing more on the transient results, we have obtained maximum sensitivity of orders greater than 10<sup>8</sup> for APTES biomolecule with respect to air and a significant selectivity value in orders of 10<sup>3</sup> for APTES with respect to Biotin biomolecule. The performance of the device in terms of selectivity can be further improved (~10<sup>4</sup>) by optimizing the back-gate bias, and therefore, the impact of back-gate bias has been analysed. The results for charged biomolecules and partially filled cavity are further investigated & highlighted. The DM <inline-formula> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula>-TFET biosensor shows a significant improvement in the results with the transient response for biosensing applications with the feasibility of operating at low voltages (gate voltage of −2.0 V, drain voltage of −0.5 V and back gate voltage 0 to 0.5 V).
Gaurav Siddharth, Vivek Garg, Brajendra S. Sengar, and Shaibal Mukherjee
Elsevier
Gaurav Siddharth, Ruchi Singh, Vivek Garg, Brajendra S. Sengar, Mangal Das, Biswajit Mandal, Myo Than Htay, Mukul Gupta, and Shaibal Mukherjee
Institute of Electrical and Electronics Engineers (IEEE)
Multiple quantum wells (MQWs) of CdZnO/ZnO are realized, for the first time, by dual ion beam sputtering (DIBS) system at different deposition conditions in terms of ion beam power, substrate temperature, and time cessation between deposition of successive layers. The effects of DIBS deposition conditions are analyzed by secondary ion mass spectroscopy (SIMS) and high-resolution transmission electron microscopy (HRTEM) and discussed systematically. The SIMS analysis has been used for depth profiling of CdZnO/ZnO-based MQWs structure. The deposition of CdZnO/ZnO-based MQW structure performed at 100 °C with time cessation of 30 min between successive layer growth and ion beam power of 14 W has displayed the best results in terms of distinct well and barrier layers formation. This work also includes an analytical study of CdZnO/ZnO-based MQW solar cell (MQWSC), in which a study is performed for solar irradiance dependence of performance parameters to explore the potential use of CdZnO/ZnO-based MQWSC for concentrator solar cell (SC). The short-circuit current density increases from 0.12 to 57.98 mA/cm2, the open-circuit voltage rises from 2.60 to 2.77 V, and the photon conversion efficiency is from 2.85% to 3.04%, as solar irradiance increases from 0.1 to 50 suns. The results show that the performance of SCs can be improved by using concentrators and also explore the possibility of efficiently absorbing short-wavelength photons.
Praveen Dwivedi, Amitesh Kumar, Brajendra S. Sengar, Vivek Garg, and Rohit Singh
IEEE
In this work, we investigate the effect of back-gate voltage on sensing metric of Dielectric Modulated (DM) Tunnel Field Effect Transistor (TFET) biosensor. Under this work we have investigated transfer characteristics, the variation of energy band, and hole concentration with back gate voltage and calculated the drain current sensitivity and selectivity for three different value of back-gate voltage. In this work, we have shown that with positive back gate voltage, drain current sensitivity is improved by nearly one order of magnitude and selectivity value is also enhanced by more than 2 times.
Amitesh Kumar, Praveen Dwivedi, Brajendra S. Sengar, Vivek Garg, and Rohit Singh
IEEE
Resistive Random Access Memories (RRAMs) or Memristor has been a revolution in current nonvolatile memory technology. This work demonstrates an analytical model that shows the effect of applied bias on the metal-semiconductor interface to affect resistive switching of an RRAM device. The applied bias modulates the corresponding interface in terms of various interfacial electrical parameters. Besides, the change in bias affects the distribution of bulk defects primarily oxygen vacancies as well as non-lattice oxygen ions. This, in turn, also affects the corresponding resistance of bulk as well as other electrical parameters at the interface. Further conduction mechanism of the device with interfacial oxide formation as well as dissolution to impact resistive switching behavior has been elaborated.
Gaurav Siddharth, Brajendra S. Sengar, Vivek Garg, Md Arif Khan, Ruchi Singh, and Shaibal Mukherjee
Institute of Electrical and Electronics Engineers (IEEE)
This article presents analytical and simulation evaluation of multiple quantum well solar cells (MQWSC) with CdZnO/ZnO as the intrinsic layer, Sb-doped ZnO (SZO) as a p-type layer, and Ga-doped ZnO (GZO) as an n-type layer of the p-i-n solar cell (SC). The material parameters used in this article are obtained from the experimental reports on the properties of ZnO and CdZnO thin films grown by dual-ion-beam sputtering (DIBS). The American Society for Testing and Materials (ASTM) standards data sheets have been utilized for attaining photon flux density instead of the blackbody radiation formula. The analytically obtained results show good agreement with the simulated results obtained by the ATLAS simulation tool. The variation of device performance parameters is examined for thermal stability. The results show that, for the proposed ZnO-based MQWSC, the open-circuit voltage (<inline-formula> <tex-math notation="LaTeX">${V}_{{\\text {oc}}}$ </tex-math></inline-formula>) has a negative temperature coefficient (−2.63 mV/°C), and short-circuit current density (<inline-formula> <tex-math notation="LaTeX">${J}_{{\\text {sc}}}$ </tex-math></inline-formula>) and conversion efficiency (<inline-formula> <tex-math notation="LaTeX">${\\eta }$ </tex-math></inline-formula>) have positive temperature coefficients of <inline-formula> <tex-math notation="LaTeX">$2.43\\times 10^{{-{3}}} \\,\\,{\\text {mA}/\\text {cm}^{{{2}}}\\cdot ^{\\circ }}\\text{C}$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$2.91\\times 10^{{-{3}}}$ </tex-math></inline-formula> %/°C, respectively. Further, the device performance has been explored for variation in the number of quantum wells. The results present that an increase in the number of quantum wells has a negative impact on the performance parameters of ZnO-based MQWSC.