AMIT KUMAR
Articles written in Bulletin of Materials Science
Volume 36 Issue 3 June 2013 pp 403-409
Sushant K Rawal Amit Kumar Chawla R Jayaganthan Ramesh Chandra
The present paper deals with deposition of titanium and zirconium oxynitride films prepared from cosputtering titanium and zirconium targets by reactive RF magnetron sputtering. The effect of power variation on various properties of the deposited films is analysed. The film gets transformed from amorphous to well crystalline oxynitride films with gradual increase of target powers as observed from XRD graphs. The films exhibit hydrophilic and hydrophobic behaviours depending upon the presence of various phases. Surface energy decreases as the film properties change from hydrophilic to hydrophobic due to greater contact angle values. The optical properties were measured by UV–Vis–NIR spectrophotometer, transmission spectra and bandgap values show variation with respect to change in elemental composition as determined from EDS analysis.
Volume 37 Issue 2 April 2014 pp 295-300 Electronic Supplementary Material
Ultraviolet sensing properties of polyvinyl alcohol-coated aluminium-doped zinc oxide nanorods
Kanchan Saxena Amit Kumar Nishant Malik Pramod Kumar V K Jain
Undoped and aluminium (Al)-doped zinc oxide (ZnO) nanorods have been synthesized by electrochemical route. The synthesized materials have been characterized by X-ray diffraction, UV–visible spectrometer and scanning electron microscope. The Al-doped ZnO nanorods have been coated with polyvinyl alcohol. Current–voltage characteristics have been investigated in dark and under UV-light illumination. Aluminium doping in ZnO increase its electrical conductivity and further polyvinyl alcohol coating on Al-doped ZnO increase UV sensitivity of the material. Response and recovery time of Al-doped ZnO and PVA-coated Al-doped ZnO nanorods have been recorded. PVA-coated Al-doped ZnO nanorods shows very fast response and recovery time of 10 s in comparison to uncoated ZnO (20 min) nanorods.
Volume 38 Issue 3 June 2015 pp 769-772
Thromboresistance of functionalized poly(methylmethacrylate): the effect of surface polarity
Govinda Kapusetti Monika Amit Kumar Ray Nira Misra
An implant material when comes in contact with blood fluids (e.g., blood and lymph), adsorb proteins spontaneously on its surface. Notably, blood coagulation is influenced by many factors, including mainly chemical structure and polarity (charge) of the material. The present study describes the methodology to improve the blood compatibility of poly(methylmethacrylate) (PMMA) by incorporating ionic groups with varying polarities. PMMA has been functionalized with different groups containing positive, negative and neutral polarity by the free radical polymerization technique and suchmodification were further confirmed through Fourier transform infrared (FTIR) spectroscopy. The level of thrombogenicity was found three times lower with negatively charged PMMA in comparison to those of positively charged and neutral PMMA. Platelet adhesion was noted almost negligible in all samples after 10 s of blood exposure. High adsorption of fibrinogen from the blood was noticed in the test sample containing a group with positive polarity (thiouronium chloride) while there was no platelet adhesion observed even after 120 s of blood exposure in the test samples containing negatively charged (sulphate) and neutral (hydroxyl group) functional groups.
Volume 41 Issue 6 December 2018 Article ID 0159
SONAL SINGHAL AMIT KUMAR CHAWLA HARI OM GUPTA RAMESH CHANDRA
We report the effects of annealing in conjunction with CdCl$_2$ treatment on the photovoltaic properties of CdTe/Zn$_{0.1}$Cd$_{0.9}$S thin film solar cells. CdTe layer is subjected to dry CdCl$_2$ treatment by thermal evaporation method and subsequently, heat treated in air using a tube furnace from 400 to 500$^{\circ}$C. AFM and XRD results show improved grain size and crystallographic properties of the CdTe film with dry CdCl$_2$ treatment. This recrystallization and grain growth of the CdTe layer upon CdCl$_2$ treatment translates into improved photo-conversion efficiencies of CdTe/Zn$_{0.1}$Cd$_{0.9}$S cell. The results of dry CdCl$_2$ treatment were compared with conventional wet CdCl$_2$ treatment. Photo-conversion efficiency of 5.2% is achieved for dry CdCl$_2$-treated cells in comparison with 2.4% of wet-treated cell at heat treatment temperature of 425$^{\circ}$C.
Volume 43 All articles Published: 20 April 2020 Article ID 0111
Magnetotactic curcumin iButtonbots as efficient bactericidal agents
TAMANNA BHUYAN AMIT KUMAR SINGH SIDDHARTHA SANKAR GHOSH DIPANKAR BANDYOPADHYAY
The microbial contamination of drinking water is one of the most major concerns of community health in the developing world. Numerous water-borne pathogens are rapidly evolving and becoming resistant to traditional antibiotics.To get an efficacious bactericidal response, an assembly of several antibiotics or increased dosage are being administered, which may produce adverse side effects after prolonged use. Here, we describe a proficient method for disinfecting waterborne coliform bacterial strains of
Volume 45 All articles Published: 5 December 2022 Article ID 0242
Charge transport studies of highly stable diketopyrrolopyrrole-based molecular semiconductor
SARDUL SINGH DHAYAL ABHIMANYU NAIN RITU SRIVASTAVA AKSHAYA K PALAI RAJESH PUNIA AMIT KUMAR
In the last decade, the diketopyrrolopyrrole (DPP)-based molecular semiconductors received significant prominence for its ability to build ambient
stable donor–acceptor type organic materials for numerous microelectronics applications, especially in organic thin-film transistors and photovoltaics. This research article demonstrates the charge
transport properties of 3,6-bis(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2,5-dihexadecylpyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione[DPP(PhNMe$_2$)$_2$] in single layer device structure prepared
by thermal evaporation technique in the frequency and temperature range of 10$^2$–10$^6$ Hz and 133–273 K, respectively. An initial impression of Nyquist plot suggests metal-like behaviour as the impedance
increases with an increase in temperature. Semicircle in Nyquist plot suggests Debye-type relaxation. This result has been explained mathematically and fitted equivalent circuit (contact resistance + parallel combination
of resistance and capacitance) of device. Resonance frequency have been estimated by the Nyquist plot and crosschecked by Joncher’s Power Law. The frequency exponent ‘
Volume 46, 2023
All articles
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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