Keshav Rajpure

Keshav Rajpure
Shivaji University, Kolhapur · Department of Physics

M.Sc., Ph.D

About

215
Publications
51,670
Reads
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7,719
Citations
Additional affiliations
August 2014 - present
Shivaji University, Kolhapur
Position
  • Professor (Full)
June 1999 - August 2014
Shivaji University, Kolhapur
Position
  • Lecturer
January 1999 - present
Shivaji University, Kolhapur
Education
June 1996 - June 1999
Shivaji University, Kolhapur
Field of study
  • thin films
June 1992 - June 1994
Shivaji University, Kolhapur
Field of study
  • Solid State Physics
June 1989 - June 1992
Sharadchandra Pawar College of Arts Science and Commerce, Lonand, MS, India
Field of study
  • Physics

Publications

Publications (215)
Article
The present investigation reports on the degradation of benzoic acid (BA) and methyl blue (MB) dye using spray deposited (area 64 cm²) Bi2WO6 photoelectrode. The experimental result shows high degradation efficiency in the photoelectrocatalytic method than in photocatalysis. Around 72 and 98% degradation of BA and MB dye was observed in 400 and 160...
Article
Full-text available
The Ag/ZWO/FTO resistive switching (RS) device was fabricated using the chemical spray pyrolysis method. The crystalline phase, morphology, and atomic composition were characterized effectively through different physicochemical techniques. The fabricated device exhibits bipolar resistive switching behavior with switching voltage below ±2 V, an HRS/...
Article
Full-text available
A comparative study of spray-deposited NixZn1−xFe2O4 (x = 0 to 0.5) thin films has been performed specifically on their structural and gas sensing properties. The films were characterized by X-ray diffraction and field emission scanning electron microscopy. The structural and morphological study reveal the formation of nanocrystalline cubic spinel...
Article
This work reports the preparation of polycrystalline titanium dioxide (TiO2) thin films using spray pyrolysis technique at various temperatures to access their photoelectrocatalytic (PEC) performance. The films were characterized by photocurrent response measurements, X-ray diffraction, Scanning electron microscopy, Elemental analysis, Fourier-tran...
Article
In this work, visible region active Bi2WO6 thin films with variable thickness are successfully deposited by simple and effective spray pyrolysis technique. The structural, optical, morphological and photoelectrochemical properties of synthesized thin films were studied. Rietveld refinement of the structural data tested purity and degree of crystall...
Article
Proliferation in research investigations on Neuromorphic computing applications is evidenced recently, with memristor as a promising and potential candidate. For such an application, an electronic synaptic device is an essential building block. We utilize the spray deposition technique to fabricate a tungstate (FeWO4, FWO) based RS device (Ag/FWO/F...
Article
The present work demonstrates the development and investigation of bipolar resistive switching characteristics of the Al/Bi2WO6/FTO thin-film memristive device. The Bi2WO6 (BWO) active layer was deposited on FTO coated glass substrates using a spray pyrolysis technique and the effect of spray volume on resistive switching characteristics was invest...
Article
In this work, nanocrystalline Cu-Ni-Zn ferrite thin films were deposited by the cost-effective spray pyrolysis technique and characterized for structural, elemental, morphological, and gas sensing properties. The XRD confirmed the nanocrystalline film. The morphology of the sample was found with surface pores as a consequence of porogen activity. T...
Article
Full-text available
Gas sensors working at lower temperatures are considered better since they consume less energy. Many transition metal oxides have received greater attention in the development of potential gas sensors. In this work, we deposited copper substituted zinc ferrite thin films by spray pyrolysis at an optimized 375°C substrate temperature. The structural...
Article
Full-text available
Titanium dioxide (TiO2) and doped TiO2 have emerged as efficient photocatalytic materials for the degradation of harmful dyes released in water. The doping significantly increases the photocatalytic activity of TiO2 by enhancing light absorption in visible region and by alteration of structure, surface area and morphology etc. The doping of TiO2 ha...
Article
The semiconducting metal oxides are the most studied chemiresistive sensing materials. Their surface morphology plays an important role in sensing response. The porous nature of the material can significantly enhance their sensing ability. With this aim, ZnFe2O4 thin films were deposited on glass substrates by spray pyrolysis technique. The added N...
Article
Full-text available
The present work reports the synthesis of titanium dioxide (TiO 2) thin films deposited from etha-nolic titanium diisopropoxide bis-acetyl acetonate precursor solution by using spray pyrolysis technique. The deposition of films were carried out on both amorphous and fluorine doped tin oxide (F:SnO 2) glasses. The effect of film thickness on photoel...
Article
Full-text available
This review accounts, various metal oxide and metal sulfide thin films are available for photodegradation of several organic compounds. Due to difficulties in recycling and to avoid rigorous recollection of power catalysts, the thin film catalyst gaining rapid attention for photocatalytic applications. The semiconducting thin films are growing as p...
Article
Metal-Semiconductor-Metal ultraviolet photodetector was fabricated by painting silver contacts on dip coated TiO2 thin films. The number of deposition cycles have influence on physiochemical properties and UV sensing properties. The UV photodetector properties were studied by illuminating devices with light intensity of 1.8 μW/cm² and 5 V bias. The...
Article
Full-text available
NO2 sensors based on Zn2SnO4 (Zinc Stannate) films were synthesized using spray pyrolysis method. The effect of substrate temperature (phase formation) on NO2 response is studied. XRD, SEM and AFM techniques were used to study structural, morphological and topographical analysis of the films, respectively. Zn2SnO4 films exhibits polycrystalline nat...
Article
A metal–semiconductor–metal (MSM) ultraviolet photodetector has been fabricated by using hydrothermally-grown TiO2 thin films. Ag paint was used as a contact electrode which showed the good ohmic contact between the metal–semiconductor junctions. The effect of deposition time on the structural, morphological and photodetector properties have been s...
Article
Fe2O3/ZnO thin films are synthesized onto glass and fluorine doped tin oxide (FTO) coated glass substrates by simple spray pyrolysis technique. The effect of ZnO layer on structural, optical, morphological and photocatalytic properties of films has been studied. All synthesized films are polycrystalline having rhombohedral and hexagonal crystal str...
Article
In this study, the nanocrystalline ZnFe2O4 thin films were deposited using spray pyrolysis technique. The structure, morphology, and optical and electrical properties of the sample were analyzed. The film shows higher conductivity for selective illumination having wavelength corresponding to the bang gap energy. In case of thermal excitation the ra...
Article
In this article, we have used double exposure digital holographic interferometry (DEDHI) technique for surface deformation study and hologram recording during synthesis of the Bi2Te3 thin films by electrodeposition method. The synthesized Bi2Te3 thin films were characterized structural, morphological, electrochemical, wettability and surface deform...
Article
Full-text available
Spray pyrolysis technique is used for the preparation of Fe2O3 thin films onto glass and fluorine doped tine oxide (FTO) coated glass substrates. The effect of thickness (Fe2O3 film) on to structural, optical, morphological, compositional and photocatalytic properties of films are studied. All the deposited Fe2O3 films are polycrystalline with rhom...
Conference Paper
Full-text available
Within a decade since the fourth fundamental passive circuit element, Memristor, was first practically realized, it has gathered a huge interest for applications in neuromorphic computing, reconfigurable circuits and resistive random access memory (RRAM). In the present study, we have investigated the properties of Ag/CoFe 2 O 4 /FTO thin film memr...
Article
Full-text available
Fe2O3 thin films have been successfully synthesized by chemical spray pyrolysis technique. The effect of solution quantities onto the photoelectrochemical (PEC), structural, morphological, and optical properties has been studied. Film prepared at 50 ml solution quantity shows the maximum photoelectrochemical performance in 0.1 M NaOH electrolyte. X...
Article
Bismuth Telluride (Bi2Te3) thin films are prepared onto the stainless steel substrates by electrodeposition technique. Effects of varying deposition time on physico-chemical properties of Bi2Te3 thin films are studied. X-ray diffraction (XRD) analysis shows that all the Bi2Te3 films are polycrystalline in nature and it has Rhombohedral crystal stru...
Article
Full-text available
In the present investigation, we have experimentally demonstrated the bipolar resistive switching with the coexistence of three fundamental memelements in the Ag/CoFe2O4/FTO thin film metal-insulator-metal (MIM) device. The device shows the analog resistive switching behavior and charge transport follows the Ohmic and space charge limited conductio...
Article
Full-text available
In the present investigation, we have fabricated copper oxide (CuO) thin film memristor by employing a hydrothermal method for neuromorphic application. The X-ray diffraction pattern confirms the films are polycrystalline in nature with the monoclinic crystal structure. The developed devices show analog memory and synaptic property similar to biolo...
Article
ZnO thin films were deposited with different solution quantities using spray pyrolysis technique. The effect of thickness variations on photoelectrochemical (PEC), structural, morphological and optical properties are studied. PEC measurements showed maximum photo response about Isc = 0.485 mA and Voc = 632 mV at 1.65 μm film thickness. X-ray diffra...
Article
In order to realize artificial intelligence using an electronic device, it is obligatory to develop a functional solid-state device that mimics synaptic plasticity, analog memory, and forgetting effect exhibited by the biological neurons. In this context, the memristor is an ideal candidate owing to its nonlinearity, passivity, and in-memory comput...
Article
Highly selective metal-semiconductor-metal (MSM) Ultra-Violet (UV) photodetectors were successfully demonstrated based on pinecone shaped zinc oxide (ZnO) films. The pinecone shaped ZnO photodetectors were synthesized via successive ionic layer by adsorption and reaction method (SILAR). The MSM device with silver (Ag) as contact electrode, possess...
Article
WO3, Ga:WO3 and bilayered TiO2/Ga:WO3 photocatalysts are synthesized by spray pyrolysis technique. Synthesized films are characterized by various characterization techniques such as structural, morphological and photoelectrochemical properties. Synthesized films are polycrystalline in nature. The TiO2/Ga:WO3 photoelectrode exhibits highest photocur...
Article
Full-text available
In this paper, we report the effect of the write voltage and frequency on memristor-based resistive random access memory (RRAM). The above-said parameters have been investigated on the linear drift model of the memristor. With a variation of write voltage from 0.2 to 1.2 V and a subsequent frequency modulation from 1, 2, 4, 10, 100 and 200 Hz, the...
Article
Polycrystalline WO3 and Ga:WO3 thin films are synthesized by spray pyrolysis technique. The photoelectrochemical (PEC) performance of PEC cell composed with WO3 and Ga:WO3 films are tested in 0.01 M HClO4. Optimized 2 at. % Ga:WO3 photoelectrode exhibits a high photocurrent density (Iph = 1.251 mA/cm² at 1.5 V/SCE) which is 1.97 times greater than...
Article
Polycrystalline CoFe2O4 thin films are deposited onto the quartz substrates by spray pyrolysis technique. Rietveld refinement analysis confirmed the films are polycrystalline in nature with spinel cubic crystal structure. Rietveld refinement analysis was employed to estimate the cation distribution in spinel lattice sites. Surface micrographs shows...
Article
Pure WO3 and Yb:WO3 thin films have been synthesized by spray pyrolysis technique. Effect of Yb doping concentration on photoelectrochemical, structural, morphological and optical properties of thin films is studied. X-ray diffraction analysis shows that all thin films are polycrystalline nature and exhibit monoclinic crystal structure. The 3 at% Y...
Article
Full-text available
In this paper, we report the effect of filament radius and filament resistivity on the ZnO, TiO2, WO3 and HfO2 based Resistive Random Access Memory (RRAM) devices. We resort to the thermal reaction model of RRAM for the present analysis. The results substantiate decrease in saturated temperature with increase in the radius and resistivity of filame...
Article
In this paper, we report the effect of filament radius and filament resistivity on the ZnO, TiO2, WO3 and HfO2 based Resistive Random Access Memory (RRAM) devices. We resort to the thermal reaction model of RRAM for the present analysis. The results substantiate decrease in saturated temperature with increase in the radius and resistivity of filame...
Article
We report the magnetoelectric (ME) coupling in lead-free ME composites composed of Metglas (2605SA1) and K0.5Na0.5NbO3 (KNN) phases. Thickness of the magnetostrictive layers (tm) is changed by stacking number of Metglas layers (t=25μm for each layer) while KNN is maintained at a fixed thickness (tp=300μm). As the number of Metglas layers increased,...
Article
Full-text available
In the present work nanocrystalline dysprosium substituted Ni0.8Co0.2Fe2−xDyxO4 (x = 0.00, 0.025, 0.050, 0.075 & 0.1) ferrite system was synthesized by the solution combustion method. The phase formation has been confirmed by Reitveld analysis of XRD patterns, which is a characteristic of spinel ferrite with most intense (311) peak. The bond length...
Article
The thin films of WO3 were deposited with different solution quantities using chemical spray pyrolysis technique. The WO3 film thickness effect on the photoelectrochemical, structural, morphological and optical properties is studied. Polycrystalline, monoclinic WO3 films possess photoelectrochemical performance having onset potentials around +0.3 V...
Article
Full-text available
The Ni0.4Zn0.6Fe2O4 ferrite, BaTiO3 ferroelectric and Ni0.4Zn0.6Fe2O4–BaTiO3 bilayered magnetoelectric thin films have been synthesized onto the quartz substrates at optimized substrate temperatures (400, 250 °C) using the simple spray pyrolysis technique. These films were characterized for their structural, morphological, dielectric and magnetic p...
Article
Full-text available
In order to find out new approaches for sensor devices, gas sensor and UV photodetector having higher sensitivity and responsivity was fabricated. ZnO thin films were synthesized by using inexpensive successive ionic layer by adsorption and reaction method (SILAR) on the amorphous glass substrate. The fabricated metal-semiconductor-metal (MSM) UV p...
Article
Full-text available
In this paper, we report the effect of filament radius and filament resistivity on the saturated temperature of ZnO, TiO2, WO3 and HfO2 Resistive Random Access Memory (RRAM) devices. We resort to the thermal reaction model of RRAM for the present analysis. The results substantiate decrease in saturated temperature with increase in the radius and re...
Article
Full-text available
In this paper, we report the effect of write voltage and frequency on memristor based Resistive Random Access Memory (RRAM). The above said parameters have been investigated on the linear drift model of memristor. With a variation of write voltage from 0.2V to 1.2V and a subsequent frequency modulation from 1, 2, 4, 10, 100 and 200 Hz the correspon...
Article
Full-text available
WO3 thin films have been deposited using simple chemical spray pyrolysis technique and successfully applied as photoanode for photoelectrocatalytic degradation of methylene blue. The films were deposited on bare glass and fluorine doped tin oxide coated glass substrates to study photoelectrochemical (PEC) properties, crystal structure, surface morp...
Article
Full-text available
Ag/ZnO/Ag metal-semiconductor-metal (MSM) Ultraviolet (UV) photodetectors based on Zinc oxide (ZnO) thin films are successfully fabricated on the glass substrate by using chemical bath deposition (CBD), which shows the good ohmic contact behavior between metal-semiconductor junctions. The devices are characterized to investigate the effect of depos...
Article
Full-text available
Barium titanate (BaTiO 3) thin films have been prepared using the spray pyrolysis method. The films were deposited onto a glass substrate at varying substrate temperature ranging from 250 to 350 °C with the interval of 50 °C. The structural, morphological , electrical and dielectric properties of the deposited films have been studied. The X-ray dif...
Article
Full-text available
The unique nonlinear relationship between charge and magnetic flux along with the pinched hysteresis loop in I-V plane provide memory with resistance combinations of attribute to Memristor which lead to their novel applications in non volatile memory, nonlinear dynamics, analog computations and neuromorphic biological systems etc. The present paper...
Article
In the present work, nanocrystalline Li0.5−0.5xCoxFe2.5−0.5xO4 (for x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) ferrite systems were synthesized by solution combustion method. The Rietveld analysis of X-ray result confirms the formation of a single phase spinel cubic crystal structure of the ferrite sample. The lattice constant of the material increase...
Article
Cobalt ferrite thin films were deposited onto quartz substrates by spray pyrolysis technique and their gas sensing properties were investigated. X-ray diffraction study confirms that films are polycrystalline in nature and exhibit single phase spinel cubic crystal structure. DC electrical resistivity measurement indicates the semiconducting nature...
Article
Full-text available
WO3 thin films have been deposited onto glass and FTO coated glass substrates using a simple chemical spray pyrolysis technique. The structural, morphological, optical and photocatalytic properties of WO3 thin films are studied. The photoelectrochemical (PEC) study shows that, both short circuit current (I sc) and open circuit voltage (V oc) are (I...
Article
Full-text available
WO3 thin films have been deposited onto glass and FTO coated glass substrates using simple chemical spray pyrolysis technique. The effect of solution concentration on the photoelectrochemical (PEC), structural, morphological and photoelectrocatalytic properties has been investigated. The structure and morphology of WO3 photoelectrodes are studied b...
Article
Full-text available
The unique nonlinear relationship between charge and magnetic flux along with the pinched hysteresis loop in I-V plane provide memory with resistance combinations of attribute to Memristor which lead to their novel applications in non volatile memory, nonlinear dynamics, analog computations and neuromorphic biological systems etc. The present paper...