Vinod Kumar

Vinod Kumar
University of the West Indies, St. Augustine | UWI

PhD

About

161
Publications
62,610
Reads
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6,219
Citations
Introduction
I am working as a faculty member at UWI. Before joined here, I had worked at DaDU Ethiopia, Indian Institute of Technology (IIT) Delhi, India; UCA France; TU US; UFS South Africa and IUAC India. My research interest is energy and environment.
Additional affiliations
March 2018 - present
UCA, France
Position
  • PostDoc Position
September 2008 - October 2009
University of Delhi
Position
  • Researcher
December 2015 - present
Indian Institute of Technology Delhi
Position
  • Inspire Faculty

Publications

Publications (161)
Book
Advanced Materials and Technologies for Photovoltaics addresses the key questions relating to the development of materials and technologies used in photovoltaic energy conversion. The book describes the fundamental and theoretical aspects of photovoltaic energy conversion, and then investigates each of the main technologies developed in this field....
Chapter
Nanostructures have attracted huge interest as a rapidly growing class of materials for numerous applications in science and technology. Several techniques have been used to characterize the size, shape, crystal structure, elemental composition, and a variety of other physical properties of nanostructures. Different kinds of nanostructures have bee...
Chapter
Nanostructures have attracted huge interest as a rapidly growing class of materials for numerous applications in science and technology. Several techniques have been used to characterize the size, shape, crystal structure, elemental composition, and a variety of other physical properties of nanostructures. Different kinds of nanostructures have bee...
Conference Paper
The incorporation of two dimensional MXenes with perovskite solar cells have garnered much attention in recent years. MXenes of the form Ti3C2Tx have shown unique electrical capabilities due to its surface terminating functional group Tx. Additionally, the inclusion of this material to perovskite solar cells has resulted in enhanced efficiency and...
Article
Full-text available
The incorporation of two dimensional MXenes with perovskite solar cells have garnered much attention in recent years. MXenes of the form Ti3C2Tx have shown unique electrical capabilities due to its surface terminating functional group Tx. Additionally, the inclusion of this material to perovskite solar cells has resulted in enhanced efficiency and...
Conference Paper
Full-text available
The incorporation of two dimensional MXenes with perovskite solar cells have garnered much attention in recent years. MXenes of the form Ti3C2Tx have shown unique electrical capabilities due to its surface terminating functional group Tx. Additionally, the inclusion of this material to perovskite solar cells has resulted in enhanced efficiency and...
Article
Full-text available
Photovoltaic (PV) systems are regarded as clean and sustainable energy sources and exhibit minimal pollution during their lifetime. The production of hazardous contaminants contaminating water resources, emissions of air pollutants during the manufacturing process, and the impact of PV installations on land use are important environmental factors t...
Article
Full-text available
The Gd-doped ZnO/SnO2 nanocomposites with various atomic percentages (0, 0.5, 0.8, and 1.2 at%) of gadolinium (coded as GdZS0, GdZS1, GdZS2, and GdZS3) was synthesis via the sol–gel method and explored for photodegradation against dye solutions exposing solar light irradiation. The synthesized nanocomposites were characterized employing the XRD, FT...
Article
Full-text available
We investigated photomolecular-induced evaporation, wherein photons cleave off water clusters near water–vapor interfaces, bypassing the typical thermal evaporation process. However, thermal-induced evaporation is the main bottleneck to precisely identify photon-induced evaporation. Liquid drop interferometry (LDI) resolved this bottleneck, utilizi...
Article
Nanotechnological materials have enormous potential for various applications. The physical and chemical properties of nanomaterials are varied and depending on the size, structure, shape, and synthesis techniques. Sonochemistry is one of the potential synthetic techniques for producing noble nanomaterials. When an aqueous solution is exposed to ult...
Article
Full-text available
The problems with traditional solar cells are mainly their high cost and low conversion efficiency, which severely restricts the advancement of these cells in real-world uses. Therefore, in order to maximise the efficiency of GaAs/AlGaAs thin-film heterostructures, GaAs/AlGaAs solar cells were numerically simulated along with Mo(S,Se)2 and CH3NH3Pb...
Article
The problems with traditional solar cells are mainly their high cost and low conversion efficiency, which severely restricts the advancement of these cells in real-world uses. Therefore, in order to maximise the efficiency of GaAs/AlGaAs thin-film heterostructures, GaAs/AlGaAs solar cells were numerically simulated along with Mo(S,Se)2 and CH3NH3Pb...
Technical Report
Full-text available
"Microbial fuel cells, thin-film solar panels, efficient and cost-effective technologies" Report compile the UWI St Augustine’s Physics Department efforts in research to unlock the future of Renewable Energy for the Caribbean and the world
Article
Full-text available
Air-water interface deformation has been used as a testbed to resolve the momentum of light debate (Abraham-Minkowski) inside the dielectric medium, but to date, experiments or theory which have resolved this debate precisely are lacking. Here, we present the experimental observation of both momenta in a single setup. The model employed in interpre...
Article
Full-text available
Developing an effective artificial photosynthesis system that imitates natural photosynthesis is a major contemporary problem. Electrospun nanofiber (NF) photocatalysts have a lot of promise for solving worldwide environmental and energy problems. Additionally, there are still many challenges to overcome in order to increase photocatalytic efficien...
Article
Energy and the environment are two major challenges for our modern civilization and solar energy plays an important role among the renewable energy alternatives due to its availability and eco-friendly nature. One of the prominent routes for the conversion of solar energy into electrical energy is photo-voltaic technology. The dye sensitized solar...
Article
A europium doped tin oxide (SnO2:Eu3+) nanophosphor is prepared by using of solution-combustion process with a variation in the doping amount of Eu3+. The results recorded by X-ray diffraction are established that SnO2: Eu3+ has a polycrystalline tetragonal structure without phase alteration for each concentration of Eu3+. The undoped SnO2 nanopart...
Book
Defect-Induced Magnetism in Oxide Semiconductorsprovides an overview of the latest advances in defect engineering to create new magnetic materials and enable new technological applications. First, the book introduces the mechanisms, behavior, and theory of magnetism in oxide semiconductors and reviews the methods of inducing magnetism in these mate...
Article
Full-text available
Ion beam modification is a one-of-a-kind approach for engineering nanomaterials to change their chemical and physical properties. Ion beam engineering of metal oxide semiconductor nanoparticles has been performed to improve their optoelectronic properties considering their energy applications. Zinc Oxide (ZnO) is one of these developing wide band g...
Article
Full-text available
The preparation of flexible electrode, including working electrode (WE) and counter electrode (CE), for dye-sensitized solar cells (DSSCs) utilizing metal oxides using environmentally friendly sustainable TEMPO-oxidized cellulose nanofibers (TOCNFs) is reported in this work. A new type of flexible electrode for the DSSCs, which were made of cellulo...
Article
The present research article explains the upconversion emission behaviour of Ho3+-Yb3+ codoped XWO4 (X = Ba, Ca, Sr) phosphors synthesized using a solid-state reaction technique. The phase formation and structural study were confirmed through X-ray diffraction and Scanning electron microscopy analysis. The role of different host matrix on the upcon...
Article
Full-text available
Rural Ethiopian communities rely mostly on biomass fuels for subsistence and productive purposes. With an increasing population and dwindling forest resources, wood fuel consumption has exceeded its supply. Besides, people do not know ways of maximising biomass efficiency. The study involves the burning efficiencies of woods with varied moisture co...
Chapter
One‐dimensional (1D) semiconductor is very useful for the advanced hybrid devices for light emitting. Zinc oxide (ZnO) is a broadly reported semiconductor due to its stability, wide bandgap, and electrical and optical properties, which make it suitable for different applications. Lot of fabrication techniques are reported for the synthesis of ZnO n...
Article
Full-text available
Photocatalysis, a unique process that occurs in the presence of light radiation, can potentially be utilized to control environmental pollution, and improve the health of society. Photocatalytic removal, or disinfection, of chemical and biological species has been known for decades; however, its extension to indoor environments in public places has...
Article
Full-text available
Melt quenching technique is used to prepare the glasses composition (KF–CaO–B2O3) with the containing manganese oxide in the range of 0.1–0.4 wt %. Nature of the fabricated glasses is confirmed by XRD analysis. All calculated stability factors from DTA analysis increases with increasing the content of MnO. Infrared spectral analysis provided the in...
Article
A europium doped tin oxide (SnO2:Eu3+) nanophosphor is prepared by using of solution- combustion process with a variation in the doping amount of Eu3+. The results recorded by X- ray diffraction are established that SnO2: Eu3+ has a polycrystalline tetragonal structure without phase alteration for each concentration of Eu. The undoped SnO2 nanop...
Article
Nickel oxide nanoparticles (NiO NPs), composite with carbon dots (C-dots), (NiO NPs@C-dots) were synthesized, characterized and then its antibacterial activity was evaluated. NiO NPs was prepared using Buddleja polystachya Fresen leaf extract and Ni (NO3 )2 .6H2 O as precursors. The C-dots were synthesized from benzene-1-4-diammine and citric acid....
Book
This book provides an overview of the applications of ion beam techniques in oxide materials. Oxide materials exhibit defect-induced physical properties relevant to applications in sensing, optoelectronics and spintronics. Defects in these oxide materials also lead to magnetism in non-magnetic materials or to a change of magnetic ordering in magnet...
Article
The electric field-assisted spray deposition of highly conducting and transparent gallium doped zinc oxide (GZO) films, with noticeable improvement in optical, structural, and electrical properties, is reported for application in organic photovoltaics with superior device performance. The GZO films deposited with applied voltages of 0 and 2000V to...
Chapter
Polymers have been reported widely in the last few decades by the scientific community due to their versatile and adjustable chemical properties. The word “polymer” comes from the Greek words “poly,” meaning many, and “meros,” meaning parts. Therefore, the meaning of “polymer” is “many parts.” Most of the large molecules or macromolecules are polym...
Article
Upconversion (UC) emission of Er–Yb doped strontium tungstate (SrWO4:Er³⁺-Yb³⁺) thin films on silicon substrates prepared by the radio frequency (RF) magnetron sputtering method using different RF powers has been investigated and reported. The X-ray diffraction patterns showed that the tetragonal phase of SrWO4 formed with an improvement in the cry...
Article
nanocomposite thin films on glass substrate are optimized and then used for fabrication of Si based solar cells. This is an in-situ attempt towards the fabrication of the photovoltaic cells by using the composition CdO:TiO 2 on p-Si. Simultaneously, enhanced the conductivity and reduced toxicity of CdO by using TiO 2. The interfacial layer of CdO:T...
Conference Paper
Spray deposited poly (3,4 ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) is used as a hole transport layer (HTL) at different thickness. These HTL layer is characterized in terms of structural and electrical properties. The thickness of HTL layer is varied from 40 to 120 nm by altering deposition time from 20 to 60 sec. The lowest t...
Article
Thin films of the ternary polymer blend (donors PCE-10 and PCDTBT with the acceptor PC71BM in chlorobenzene) were fabricated by using spray coating technique without and with applied voltage to the nozzle during deposition. The increased absorption range from 400 nm to 800 nm indicates that Förster resonance energy transfer (FRET) is occurring for...
Article
Differently coloured TiO2 nanoparticles was fabricated by continuous spray pyrolysis (CoSP) technique due to the controlled manner of defect formation in large scale synthesis of black, green and white TiO2 with creation of selective Ti³⁺ defects as well as defects correlated to oxygen vacancies. The enhancement in the zone temperatures in CoSP fur...
Article
The present work describes the synthesis of pure and Zn doped CdO (CdO:Zn) nanorods synthesized by a simple low-cost combustion technique. The optical, structural, morphological, and surface properties, as well as antimicrobial activities of the CdO:Zn nanoparticles were studied with respect to pure CdO. UV − Vis spectrometry and photoluminescence...
Article
K2SiF6 and BaSiF6 nanoparticles are synthesized for the first time by thermal decomposition of a mixture consisting of oleic acid and 1-octadecene using ammonium fluoride as fluorine source instead of highly toxic hydrofluoric acid. The structural and morphological properties of the as-obtained nanocrystals are investigated.
Article
Highly conducting and transparent undoped and indium doped tin oxide (SnO2:In) thin films are prepared by spray technique at different doping concentration of Indium (In). The X-ray diffraction pattern of SnO2:In thin films are confirmed the tetragonal phase of SnO2. The resistivity of SnO2:In film is increased with increased the doping concentrati...
Article
Full-text available
CdO : ZnO hexagonal particles were synthesized by a sol–gel precipitation method at different annealing temperatures. A mixed crystal phase of cubic and wurtzite structures was observed from X-ray diffraction patterns. The micrographs showed hexagonal shapes of the CdO : ZnO nanocomposites particles. The energy dispersive X-ray spectroscopy mapping...
Article
Organic-inorganic hybrid solution composing of Continuous Spray Pyrolyzed (CoSP) synthesized molybdenum trioxide (MoO3) nanorods in poly(3,4-ethylene dioxy thiophene): poly(styrenesulfonate) (PEDOT:PSS) were developed to form an effective interconnecting layer for use as a hybrid hole transport layer (HTL) in organic solar cells (OSCs). Compared to...
Article
Eu³⁺ doped ZnO (ZnO:Eu³⁺) thin films were prepared by pulsed laser deposition at different oxygen partial pressures. The all ZnO:Eu³⁺ thin films have a hexagonal structure. The morphology and roughness of the ZnO:Eu³⁺ thin film were also dependent on the partial pressure of the oxygen. The strong band to band emission was observed with the weak emi...
Chapter
Rare earth doped/codoped upconversion nanoparticles facilitate anti-Stokes emission with different pump power and also show nonlinear optical properties with infrared excitation. The interesting properties such as anti-Stokes shifts, long lifetimes and sharp emissions have attracted researchers’ attention in diverse field applications. Here, in thi...
Conference Paper
Methylamionium iodo bismuthate (MBI) perovskite is a promising alternative of hybrid organic-inorganic lead perovskite devices because of its better stability and low toxicity compared to lead based perovskite. Spray deposition technique was used to deposit lead free Bismuth Iodide Perovskite thin film with different thickness. The crystal structur...
Article
Full-text available
ZnO-TiO2:0.4 mol. %Dy³⁺,x mol. %Eu³⁺ (x = 0.05, 0.15, 0.25, 0.50, and 0.75) nanophosphors were synthesized using the solgel method. X-ray diffraction data confirmed crystallization of a mixture of wurtzite hexagonal ZnO and tetragonal TiO2 (anatase and rutile) nanocomposite phases. The nanocomposites were excited in the ultraviolet region with a wa...
Article
Full-text available
Solution-processed Methylammonium iodo bismuthate (MBI) perovskite solar cell is fabricated by spray technique with changed applied voltages from 0 to 1000 V during the deposition of MBI thin film. The morphology and surface roughness of MBI films are influenced significantly by the electric field during film deposition. It is attributed to improve...
Article
Poly (3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) doped with Eu³⁺ is spray deposited for creating an Anode buffer layer (ABL). The doping of Eu³⁺ in PEDOT:PSS causes the down-shifting of the UV light to visible spectrum enhancing the photon concentration in this region. The use of electric field during the spray deposition of un...
Article
Zinc oxide (ZnO) nanoparticles were prepared by a green process using a simple sonochemical method. The prepared nanoparticles were annealed at different annealing temperatures in order to determine the role of the annealing temperature on the structural, morphological and optical properties of the prepared material. The defects related photolumine...
Article
Rare earth doped/codoped phosphors have been extensively studied for different types of applications based on their intense luminescence features. For this, researchers have tried to choose the inorganic host matrices having both a low phonon cut-off frequency and a high refractive index. Many articles have been published on oxide based phosphor ma...
Article
xZnO:(1-x)TiO2 (x = 1.0, 0.6, 0.5, 0.4, 0.0) nanocomposites powder were synthesized by sol-gel method. The X-ray diffraction results have shown a mixed phase of titanium dioxide and zinc oxide. The average crystallite size was found in the range of 20–45 nm. The absorbance of ZnO:TiO2 nanocomposite powder was measured in the wavelength range from 3...
Article
Erbium (Er³⁺) and ytterbium (Yb³⁺) co-doped ZnO upconversion (UC) nanoparticles based phosphors are synthesized by solution-combustion method. These UC phosphors are shown a strong UC emissions at red, green and blue wavelengths with the excitation of 980 nm diode laser source. To understand the influence of ZnO:Er³⁺-Yb³⁺ UC based nanoparticles on...
Chapter
The growing demand for energy-efficient materials needs advancement in existing approaches. Photon upconversion is an effective way to overcome this issue. Novel upconverting materials show their potential in the advancement of energy conservation and lighting technology. In this contest, lanthanide-activated inorganic luminescent materials play a...
Article
Y2O3:Bi³⁺ thin films of various microstructures were deposited using different deposition times by means of a radio frequency magnetron sputtering system. The deposition time affects the surface morphology, crystalline phase and the optical properties of the Y2O3:Bi³⁺ thin films. The films with the shorter and longer deposition time were amorphous...
Conference Paper
Full-text available
ZnO and CdO:ZnO nanoparticles are synthesized by sol-gel precipitation method. The structural analysis shows composite structure for CdO:ZnO nanoparticles with (002) and (111) phase. The SEM images show wedge like morphology and 3-D hexagonal morphology with ∼110 nm in size. The uniform growth of CdO:ZnO nanoparticles were observed in EDS element m...
Article
Full-text available
ZnO:Eu³⁺/Er³⁺/Yb³⁺thin films were deposited on Si (100) substrates using the sol–gel spin coating technique. The effect of Yb³⁺ concentration on the structure, particle morphology and optical properties of the films was examined. X-ray diffraction data showed that all the thin films crystallized in a hexagonal wurtzite structure of ZnO. The particl...
Article
Producing novel functional nanomaterials with high reproducibility is extremely desirable but very challenging. Further treatment by reliably combining or embedding nanoparticles into a protecting medium could be a promising approach to retain their properties and realize practical applications. In this work, we report the preparation, characteriza...
Article
A comprehensive review of up-conversion (UP) and down-conversion (DC) or down shifting of rare earth (RE) doped zinc oxide (ZnO) nanophosphors is presented. Research interest in the development of RE³⁺ doped ZnO for UP and DC nanophosphors has been encouraged by the potential application of these materials in light emitting diodes and different typ...
Article
This article reports on the frequency upconversion property of yellow light emitting Ho³⁺-Yb³⁺ embedded tungsten tellurite (TeO2-WO3) glass prepared by the famous melt-quench technique. Holmium activated TeO2-WO3 glass gives efficient visible and near-infrared upconversion luminescence upon 980 nm excitation, which improved via the incorporation of...
Article
Er³⁺/Tm³⁺ doped and codoped Na2O-SiO2-ZnO (NSZO) glasses were prepared by the conventional melt-quenching method. The amorphous nature of the prepared glasses was confirmed by the X-ray diffraction analysis. The optical absorption spectrum displayed several peaks, which correspond to Er³⁺ and Tm³⁺ dopant ions embedded into the NSZO glass. Both dopa...
Article
Cadmium oxide (CdO) thin films have been deposited onto glass substrates using different molar concentrations (0.2 M, 0.5 M and 0.8 M) of cadmium acetate precursor solutions using a sol-gel spin coating technique. The structural, morphological, optical and electrical results are presented. X-ray diffraction patterns indicated that the CdO films of...
Article
We report on the sol-gel based room temperature synthesis of undoped SnO2 and Ag-SnO2 nanostructures. The synthesized nanostructures were characterized by Fourier transform infrared spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, High-resolution transmission electron microscopy (HR-TEM) and UV-visible spectroscopy. The XRD pattern confir...
Article
This study reports on the photoluminescence and cathodoluminescence behaviour of combustion synthesized CaMoO4:Ho³⁺ phosphor. X-ray diffraction and scanning electron microscopy revealed the formation of single phase tetragonal structure consisting of well-prepared evenly distributed micro-sized grains. Power tunable visible upconversion and infrare...
Article
Dysprosium (Dy 3þ) activated ZnO-TiO 2 nanocomposite phosphors were successfully synthesized by the sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR), UVeVis spectroscopy, X-ray photoelectron spec-troscopy and photo-luminescent (PL) spectroscopy...
Article
The structure, particle morphology and luminescent properties of europium (Eu 3+) doped ZnO nanoparticles (NPs) prepared by co-precipitation method are discussed. When excited using a 325 nm He-Cd laser, undoped ZnO NPs exhibited weakly the well-known ultraviolet excitonic recombination emission (at ~ 384 nm) and strongly broad band visible emissio...
Article
The effect of sol concentration has been investigated on the sol-gel derived CdO nanostructures to optimize the optical and electrical properties enhancing gas sensing properties at low temperatures. X-ray diffraction patterns show that 0.5 M CdO film has cubic structure (111) preferred orientation with 34 nm particle size. Scanning electron microg...
Article
Rare earth Eu³⁺/Dy³⁺ ions doped/co-doped Na2O-SiO2-ZnO (NSZO) glasses were prepared by the conventional melt-quenching method. The amorphous nature of the prepared glasses was confirmed by the X-ray diffraction analysis and scanning electron microscopy whereas elemental compositions and mappings had been obtained from energy dispersive spectroscopi...
Article
The sol gel method was used to prepare rare-earths (Yb³⁺-Er³⁺ and Yb³⁺-Tm³⁺) co-doped Al2O3-TiO2 nano-composite powder phosphors and their up-conversion luminescence properties were investigated. Mixed oxides of titania (TiO2) rutile phase and an early stage crystallization of alumina (Al2O3) phase were confirmed from the X-ray diffraction data wit...
Article
Y2O3:Bi³⁺ thin films have been fabricated onto Si substrates by the radio frequency magnetron sputtering technique. The influence of different annealing temperature was studied by X-ray diffraction(XRD), Atomic force microscopy, scanning electron microscopy and Photoluminescence (PL). The XRD study revealed that, the Y2O3:Bi³⁺ thin films have a cub...
Article
In today’s times where pollution of all kinds is at its peak, numerous efforts are being made to find proper waste disposal methods. Moving on the same lines, this paper presents an economical and environmentally safe method of disposal of red mud to control electromagnetic pollution by using it as an electromagnetic shielding material. Composites...
Article
Mixed oxides of zinc and cadmium with different proportions were deposited on ordinary glass substrates using the sol-gel spin coating method under optimized deposition conditions using zinc acetate dihydrate and cadmium acetate dihydrate as precursors. X-ray diffraction patterns confirmed the polycrystalline nature of the films. A combination of c...
Article
Ytterbium (Yb³⁺) doped aluminium oxide (Al2O3) powder phosphor was successfully synthesized by solution combustion method. The structure, vibrational bending modes, particle morphology, chemical composition, and photoluminescent properties were analysed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron...
Article
The effect of different annealing temperatures on the photoluminescent properties of bismuth doped yttrium oxide (Y2-xO3:Bix)phosphor powders was investigated with various optical spectroscopy instruments for a possible down-conversion candidate for solar cells. Results showed that the emission intensity increased by increasing the annealing temper...
Article
Metal oxide semiconductors are promising materials for fabricating p-n heterojunctions which are technologically important for many electronic devices. The reason is their unique characteristics of tuneable electrical properties that can be controlled by doping. In the present work, a p-n heterojunction was fabricated by depositing nitrogen doped z...