Browsing by Author "Bhaskar Bhattacharya"

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A simple low cost method for synthesis of SnO2 nanoparticles and its characterization
(Springer Nature, 2020) Shaheen Naz; Iqra Javid; Subhrajit Konwar; Karan Surana; Pramod K. Singh; Mohit Sahni; Bhaskar Bhattacharya
Nanomaterials have gained a lot of interest due to their application in various fields. Tin oxide (SnO2) is an important n-type wide band-gap semiconductor in the field of gas sensing devices due to its chemical and mechanical stability. Here, SnO2 nanoparticles were synthesized by a simple chemical co-precipitation method followed by annealing the obtained nanoparticles at different temperatures. Several characterization techniques like powder X-ray Diffraction, Scanning Electron Microscope, Energy-Dispersive X-Ray spectroscopy, and Ultraviolet–Visible spectroscopy, Fourier Transform Infrared Spectroscopy were carried out to analyze the structure, size, morphology, elemental composition and optical properties of the prepared SnO2 nanoparticles. © 2020, Springer Nature Switzerland AG.
A simple synthesis route of low temperature CdSe-CdS core-shell quantum dots and its application in solar cell
(Elsevier B.V., 2018) Karan Surana; Ibrahim T. Salisu; R.M. Mehra; Bhaskar Bhattacharya
Synthesis of colloidal semiconductor quantum dots (QDs) has become a major research area in the field of material science. Over the last two decades QDs have been employed successfully in sensitizing the mesoporous semiconductors like TiO2, ZnO etc. in various configurations thus giving birth to a new branch of low cost solar cells known as quantum dot sensitized solar cells (QDSSCs). In this paper we report low temperature synthesis of core-shell CdSe-CdS quantum dots (QDs) using wet chemical technique. A quantum dot solar cell (QDSC) was also prepared with the core-shell QDs as working electrode and a well explored solid polymer electrolyte. The QDSC was characterized and its stability was monitored for a period of two months in laboratory conditions. © 2018 Elsevier B.V.
Analytical analysis of concentration of charge carriers in polymer electrolytes through different models
(Elsevier Ltd, 2022) Amit Saxena; Kushal Malhotra; Manali Jaithliya; Shweta Agarwal; Bhaskar Bhattacharya
The development of solid polymer electrolytes with high ionic conductivity and good chemical and mechanical stability for application in various electrochemical devices has been a critical area of research in the past few decades. For the better performance of the electrochemical devices, the compatibility between the electrodes and electrolytes of the system is the foremost requirement. In addition to this, the ion conductivity of the electrolytes is an important parameter. Understanding the mechanism of changes in ionic conductivity with different concentrations of salt and dispersoid is very crucial. In the present work, we have used three theoretical models, the Rice-Roth model, the Trukhan model and Schutt and Gerdes Model, to understand the reasons behind the variation in conductivity by calculating the concentration and mobility of charge carriers. All the required parameters of the model for the calculation purpose have been taken from Impedance Spectroscopy data. The Trukhan model is a direct method for evaluating the exact value of the diffusion coefficient. The diffusion coefficient of PEO-NaI based electrolyte thin films are calculated from the dielectric tangent loss and further used for analyzing the concentration of charge carrier and ion mobility. Similarly, two more theoretical models, Rice-Roth and Schutt & Gerdes model were used to confirm the value of the number of charge carriers. Further, all the results are compared with each other for the conclusion. © 2022
Anti-bacterial Role of Zinc Oxide Synthesized Using Naturally Abundant Material
(John Wiley and Sons Inc, 2025) Mansi; Shivank; Bhaskar Bhattacharya; S. Majumder; Jahanvi Kashyap; Yatishwar Chauhan
The large-scale chemical synthesis of nanoparticles has a very detrimental effect on the environment. Therefore, w e explored a green route for the synthesis of ZnO nanoparticles using plant extract. W e report the synthesize of ZnO nanoparticles via both green and chemical routes for comparison. Both samples are characterized using a UV-visible spectrophotometer, X-ray diffraction analysis (XRD), and a photo-illuminator. Their properties are compared, and then their antimicrobial activity is tested. Notably, the green synthesis method is cost-effective and eco-friendly compared to chemical synthesis. © 2025 Wiley-VCH GmbH.
Biogenic synthesis and thermo-magnetic study of highly porous carbon nanotubes
(Institution of Engineering and Technology, 2019) Rachana Ranu; Yatishwar Chauhan; Amar Ratan; Pramod K. Singh; Bhaskar Bhattacharya; Sandeep K. Tomar
Nanomaterials synthesis using natural sources is the technology to up come with advanced materials through extracts of plant, microorganisms, poultry waste etc. In this study, the authors report the synthesis of porous carbon nanotubes using high-temperature decomposition technique facilitated by cobalt salt using chicken fats, a poultry waste as a precursor. Since chicken fats contain fatty acids which can decompose into short hydrocarbon chains and cobalt can act as the catalyst. The formation of carbon nanotubes was confirmed by Raman spectra, peaks at 1580 and 1350.46 cm−1 confirmed the graphite mode G-band and structural imperfections defect mode D-band, respectively. Transmission electron microscopy showed the formation of tube-like structures. Nitrogen adsorption–desorption studies showed the high-surface area of 418.1 m2g−1 with an estimated pore diameter of 8.1 nm. Thermogravimetry analysis–derivative thermogravimetric analysis–differential thermal analysis showed the instant weight loss at 517°C attributed to the rapid combustion of nanotubes. A vibrating-sample magnetometer showed the paramagnetic nature of the so-formed carbon nanotubes formed. © The Institution of Engineering and Technology 2018
Carbon Quantum Dots
(CRC Press, 2023) Karan Surana; Bhaskar Bhattacharya
Quantum dots (QDs), in general, are zero-dimensional (0D) semiconducting nanosized entities whose optical and electronic behavior is intimately linked to their size. Apart from the well-known variety of chalcogenide QDs, a new league of carbon and graphene QDs has caused a major stir in the scientific community. These colorful forms of carbon are being actively pursued for their strongly tunable absorbance and fluorescent characteristics. Furthermore, they exhibit excellent biocompatibility, tunable surface functionalities, and simple synthesis routes, which have further increased their popularity. Owing to low cytotoxicity and chemical inertness, these 0D carbons have found applications in biochemical sensing, bioimaging, photovoltaics, catalysis, and drug delivery. © 2024 selection and editorial matter, Piyush Kumar Sonkar and Vellaichamy Ganesan; individual chapters, the contributors.
Cation deficiency driven enhancement in electrochemical performance of Sr2-xFeCoO6-δ double perovskite for supercapacitor electrodes
(Elsevier Ltd, 2025) Pramod Rajish Kumar; Arpita Tripathi; Harish Chandra Verma; Aayush Mittal; Bhaskar Bhattacharya; Shail Upadhyay
Properties of perovskite oxides have been tailored to fulfill the requirements of high-capacity and high-power storage devices. This is done by optimizing oxygen vacancy concentration, redox stability, and mixed (ionic and electronic) conductivity. Oxygen intercalation in perovskite oxides is a versatile and robust mechanism for improving the performance of energy storage devices. In this study, a series of non-stoichiometric (Sr-deficient) Sr2-xFeCoO6-δ double perovskite compositions are synthesized using a sol-gel method to increase oxygen vacancy concentration. X-ray diffraction confirmed the formation of a cubic phase with Pm3̅m Space group, stable up to ∼7.5 % Sr deficiency (x = 0.15). Core-level XPS of oxygen revealed that increasing Sr deficiency leads to a higher concentration of adsorbed oxygen species, indicating enhanced oxygen vacancy formation. Sr deficiency leads to a notable increase in specific charge storage capacity, from 15.5 C/g in the stoichiometric sample to 35.3 C/g in the optimized composition. In a symmetric two-electrode configuration, the optimized composition achieved an energy density of 6 Wh/kg, a power density of 780 W/kg, and retained 78 % of its capacity after 5000 cycles. © 2025 Elsevier Ltd
CHARGE CARRIER DYNAMICS IN ION CONDUCTING POLYMER ELECTROLYTES
(Nova Science Publishers, Inc., 2022) Sandhya Gupta; Bhaskar Bhattacharya
Ion conduction in polymer electrolytes is of prime interest for their choice and optimum use in electrochemical devices. Since the pioneering works of Wright and Fenton, Armand and others during more than four decades, a variety of ion conducting polymer electrolytes have been prepared and studied for their optimum applications. However, due to non availability of any mechanism for the direct measurement of either mobility of ions or their density (number per unit volume in the electrolyte) major focus remained towards increasing the conductivity and their application in batteries, supercapacitors, etc. Only a few reports were available where these two parameters have been determined by any methods and correlated with other parameters. The basics of physics tells that the conductivity (?) is equal to the product of number of charge carriers contributing to the conduction (n), their mobility (?) and the charge being carried by them. Therefore, in order to enhance the conductivity of electrolytes or at least to know the reason behind the variation in conductivity with any other parameter like doping concentration or temperature, it is absolutely essential to know the values of n or ?. It may be noted that any change in may be due to change in n, or their cumulative effects. The primary parameters n and that control the conductivity have been identified and discussed in this article. © 2022 by Nova Science Publishers, Inc.
Comparative study of fabrication and characterization of Al-ZnO based Schottky barrier diodes using Pd and Au metal contacts
(Springer New York LLC, 2019) Manisha R. Singh; Mohit Sahni; Munendra Singh; Bhaskar Bhattacharya; Naresh Kumar
This work shows a comparative study of two types of surface barrier diodes (SBDs). RF magnetron sputtering was used to fabricate Al doped ZnO films (Al0.02Zn0.98O) at two different temperatures (100 and 300 °C) and then the structural and optical properties of these thin films were obtained and analyzed using SEM, AFM, XRD, EDX and UV–Vis spectroscopy. Then the heterojunction layers Pd/Al-ZnO/p-Si (SBD1) & Au/Al-ZnO/p-Si (SBD2) were prepared using these Al-ZnO films (developed at both the temperatures). Optical and electrical properties and the effect of temperature on ideality factor, barrier potential and carrier concentration of both the SBDs were also studied. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Comparative Study on Electrical Behavior of Silicon/Fullerene/CuI Dispersed Composite Polymer Electrolytes
(Wiley-VCH Verlag, 2019) Amit Saxena; Bhaskar Bhattacharya
This paper presents the comparative study of electrical characterization for Si/C60/CuI dispersed composite polymer electrolyte thin films. Thin polymer films are prepared for different wt% of dispersoid with the host polymer electrolyte (PEO: NaI) matrix. Si and CuI are used as procured and C60 is prepared in the laboratory and the same has been verified with NMR data sheet. Furthermore, the prepared films are subjected to structural and electrical characterization. The composite nature of the films is verified with the X-ray diffraction and Fourier Transform Infrared. The complex impedance spectroscopy is used to analyze the electrical conductivity of the samples. The polarization technique is performed to calculate the transference of ion (T¬ion). The concentration and mobility of charge carries are calculated to explain and to support the change in conductivity. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Conductivity and dielectric studies of Li3+-irradiated PVP-based polymer electrolytes
(SAGE Publications Ltd, 2018) Divya Singh; D. Kanjilal; G.V.S. Laxmi; Pramod K Singh; S.K. Tomar; Bhaskar Bhattacharya
Poly(vinylpyrrolidone) (PVP) complexed with sodium iodide (NaI) is synthesized to investigate the ionic conductivity of alkaline-based polymer electrolytes. In this article, we report the modification of electrical properties of a new ion-conducting polymer electrolyte, namely, PVP complexed with NaI. Modification of polymer electrolyte was carried out before and after the exposure of films by bombarding them at different fluences with respect to Li3+ ion beam at 60 MeV. The preparation and detailed characterization of PVP:NaI is being reported. Further, a correlation with conductivity and dielectric constant has also been established. The modulation in the conductivity is explained in terms of number of charge carriers (n) and its mobility (μ), which confirms the behavior of the polymer electrolyte as an alternative strategy to improve the conductivity. © The Author(s) 2018.
Controlled carbon dots mixing boosts perylene diimide dye for enhanced absorbance and white light emission: Finding application in optoelectronic devices
(Elsevier B.V., 2025) Karan Surana; Pratibha Pansari; Roopali Sharma; Bhaskar Bhattacharya; Saurabh S. Soni; Geeta Durga
The development of white light-emitting materials is of particular importance for backlights, lighting, and full-color visual display devices. This work successfully attempts to obtain white light by mixing blue-emitting carbon dots (C-Dots) and greenish-yellow-emitting valine functionalized perylene diimide (PDI) dye in an aqueous medium. The two components were mixed in a controlled manner using the host-guest approach, i.e. adding PDI dye to C-Dots and C-Dots to PDI dye for generating C-Dots-PDI composites. The optical characterization of C-Dots-PDI composites revealed intriguing results wherein the incremental addition of C-Dots to a fixed concentration of PDI dye resulted in an unexpected enhancement in the absorbance of the PDI dye. The optimized C-Dots-PDI composites exhibited pure white light emission (CIE coordinates = 0.33, 0.33) upon excitation at 370 nm. The mechanism involved in the interaction was evaluated using photoluminescence spectroscopy, transmission electron microscopy, and cyclic voltammetry measurement. Additionally, the C-Dots were investigated for their practical application as an invisible ink for transmitting secret messages. Finally, the white light-emitting composites were evaluated for their solid-state emission and also employed as sensitizers in dye-sensitized solar cells (DSSC), which revealed the superior performance of PDI as a host and C-Dots as a dopant. © 2025 Elsevier B.V.
Corrigendum to “A simple synthesis route of low temperature CdSe–CdS core-shell quantum dots and its application in solar cell” (Optical Materials (2018) 82 (135–140), (S0925346718303318), (10.1016/j.optmat.2018.05.060))
(Elsevier B.V., 2019) Karan Surana; Ibrahim T. Salisu; R.M. Mehra; Bhaskar Bhattacharya
The authors regret having missed the name of the funding agency. The authors are thankful to Council of Scientific and Industrial Research (CSIR) for providing the Senior Research Fellowship (SRF, 9/1078(0002)/18 EMR-I. The authors would like to apologise for any inconvenience caused. © 2019 Elsevier B.V.
Deposition and study of AZO heterojunction Schottky diodes at different temperatures
(Springer New York LLC, 2018) Manisha R. Singh; Km Sucheta Singh; Shubhra Aakanksha; Mohit Sahni; Bhaskar Bhattacharya; Pallavi Gupta; Naresh Kumar
Highly transparent AZO (Al0.02Zn0.98O) films were deposited on p-type Si (100) using RF magnetron sputtering and then sintered at different temperatures (100 °C, 300 °C, 500 °C, and 600 °C). Structural properties of these films were analyzed and compared using XRD, SEM and AFM. Further, this work investigates the electrical properties of different types of Schottky junctions made with Gold metal contacts on these thin films. With the increasing fabrication temperature, both the optical band gap as well as the ideality factor were found to be decreasing. Impact of temperature variation on potential barrier of Schottky diodes and carrier concentration were also studied. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Dye sensitized solar cell based on poly(vinyl alcohol) doped with ammonium iodide solid polymer electrolyte
(National Institute of Optoelectronics, 2013) Vivek K. Singh; Annubhawi Annu; Upasana Singh; Prabhakar Singh; S.P. Pandey; Bhaskar Bhattacharya; Pramod K. Singh
A new polymer electrolyte Polyvinyl alcohol (PVA) doped with ammonium iodide (NH4I) have been developed, characterized and applied in Dye sensitized solar cell (DSSC). Polymer electrolyte shows enhancement in electrical conductivity by salt doping and then decrease after a certain composition. Infrared spectroscopy (IR) as well as x ray diffraction (XRD) affirmed composite nature of the polymer electrolyte. The polymer morphology has been studied using optical microscopy. Based on maximum conducting sample we have developed a DSSC which shows short circuit current density of 0.46 mA/cm2, open circuit voltage of 0.65 volt with overall conversion efficiency of 0.29 % at 1 sun condition.
Elaborative Studies on Non-Porous Carbon Material for Super Capacitor Application
(Wiley-VCH Verlag, 2019) Pawan S. Dhapola; Nanda G. Sahoo; Bhaskar Bhattacharya; Yogesh Kumar; Pramod K. Singh; Meenal Gupta
This study demonstrates a simplistic and effectual approach to prepare non-porous carbon for which nitrogen is doped in poly(vinyl chloride) (PVC) in presence of catalyst cobalt chloride (COCl2). Characterization of the prepared non-porous carbon is carried out using Raman, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Brunauer–Emmett–Teller. The calculated surface area of the prepared carbon is 15.78 m2 g−1. To compare the performance of prepared non-porous carbon with pure PVC as an electrode material for supercapacitor application, two EDLC cells are prepared. In both the cells, 1-ethyl-3-methylimidazolium thiocyanate (ionic liquid) is used as an electrolyte and filter paper is used as a separator. Six times increment is found in the specific capacitance value of EDLC prepared using nitrogen-doped carbon (NC-CO) than prepared using pure PVC. The calculated specific capacitance values using low-frequency impedance spectroscopy are 62.28 and 7 F g−1, respectively, for NC-CO and pure PVC. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Electrical conductivity of pectin-based biopolymer electrolytes: search for a theoretical framework
(Springer Science and Business Media Deutschland GmbH, 2024) Kailash Kumar; Ikhwan Syafiq Mohd Noor; Shri Prakash Pandey; Bhaskar Bhattacharya; Amit Saxena
This paper reports the successful fabrications of polymer electrolytes using biopolymer pectin in conjunction with ammonium azide (NaN3) salt by solution casting method. The ionic conductivity of these electrolytes was evaluated using EIS at room temperature. Among the compositions tested, the highest conductivity of 2.3 × 10−3 S cm−1 was observed to sample of 5 wt.% of NaN3. The charge carriers' concentration (n) and mobility (µ) were calculated to understand the conductivity behavior attributed to dispersoids. For the calculation of n and μ, two theoretical models were used, namely the Trukhan and the S&G Model. The correlations between conductivity, n and μ are discussed. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
Electrical conductivity of pectin-based biopolymer electrolytes: search for a theoretical framework
(Springer Science and Business Media Deutschland GmbH, 2025) Kailash Vijaya Kumar; Ikhwan Syafiq Mohd Noor; Shri Prakash Pandey; Bhaskar Bhattacharya; Amit Saxena
This paper reports the successful fabrications of polymer electrolytes using biopolymer pectin in conjunction with ammonium azide (NaN3) salt by solution casting method. The ionic conductivity of these electrolytes was evaluated using EIS at room temperature. Among the compositions tested, the highest conductivity of 2.3 × 10−3 S cm−1 was observed to sample of 5 wt.% of NaN3. The charge carriers' concentration (n) and mobility (µ) were calculated to understand the conductivity behavior attributed to dispersoids. For the calculation of n and μ, two theoretical models were used, namely the Trukhan and the S&G Model. The correlations between conductivity, n and μ are discussed. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
Electrodeposited MnO2-NiO Composites as a Pt Free Counter Electrode for Dye-Sensitized Solar Cells
(Springer, 2020) Sunanda Kakroo; Karan Surana; Bhaskar Bhattacharya
Manganese oxide-Nickel oxide (MnO2-NiO) hasbeen successfully deposited on Fluorine doped Tin Oxide (FTO) glass electrode using a facile, effective and low costelectrodeposition process and was used as counter electrode (CE) in dye-sensitized solar cells(DSSC).The cells were characterized using electrochemical impedance spectra and cyclic voltammetry, which revealed enhanced electrocatalytic ability for the reduction of triiodide/iodide (I3 − to I−). Further, the photocurrent–voltage (J–V) characteristics under the illumination of 100 mW/cm2 were studied. The DSSC with MnO2-NiO CE revealed higher short-circuit current density (Jsc) of 0.3 mA/cm2, open-circuit voltage (Voc) of 0.83 V, and fill factor of 0.84. This suggests that the electrodeposited MnO2-NiO coated FTOelectrode can be used to replace the commonly employed and expensive metal platinum (Pt) in DSSC. © 2020, The Minerals, Metals & Materials Society.
Extraction and characterization of dye from marigold flowers and its suitability for application in dye sensitized solar cell
(Institute of Physics, 2025) Swati Singh; Shivank Shivank; Karan Surana; Bhaskar Bhattacharya
The performance of dye sensitized solar cells (DSSC) is primarily influenced by the dye used as the sensitizing agent. In this context, natural dyes have emerged as a sustainable and economically viable alternative to synthetic dyes. In the current work, we have focused on the extraction and characterization of natural dye derived from Tagetes erecta and its consequent application as sensitizer in DSSC. The optical and electrochemical properties of ethanol-based Tagetes erecta dye was measured by UV–vis absorption spectroscopy, photoluminescence spectroscopy, Fourier transform infra-red spectroscopy, and cyclic voltammetry analysis. The fabricated DSSC using the extracted dye demonstrated a strong response to visible light with an open circuit voltage of 0.60 V, and a photon conversion efficiency of 0.02% using quasi-solid polymer electrolyte. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.