The influence of single walled carbon nanotube（SWCNT）on the series resistanceof Rose Bengal（RB）and Methyl Red（MR）dye-based organic diodes has been studied.It has been revealed from experimental results that SWCN...The influence of single walled carbon nanotube（SWCNT）on the series resistanceof Rose Bengal（RB）and Methyl Red（MR）dye-based organic diodes has been studied.It has been revealed from experimental results that SWCNT has a significant effect on Rs.The values of Rs are measured from current–voltage（I–V）characteristics and also by utilizing the Cheung method.Obtained values from the Cheung method have been verified using H（I）–I plots for all dye-based devices.The extracted values using these two processes show a good consistency with each other.It is observed that Rs is reduced significantly by incorporating SWCNT for both dyes.The estimated amounts of reduction of Rs using SWCNT are 76.08%and 64.23%obtained from the I–V relationship whereas the value of Rs shows a reduction of 83.5%and 67.1%when measured by using the Cheung method for RB and MR dyes respectively.The ideality factor and barrier height of the diodes have also been extracted.The ideality factor has decreased with incorporation of SWCNT.A reduction in barrier height for the devices has also been observed in the presence of SWCNT.展开更多
Functionalized single-walled carbon nanotubes(f-SWCNTs)hybridized with freshly prepared zinc oxide(ZnO)nanocrystals have been found to be good luminescent material with tuned emission properties.A three-phase nanocomp...Functionalized single-walled carbon nanotubes(f-SWCNTs)hybridized with freshly prepared zinc oxide(ZnO)nanocrystals have been found to be good luminescent material with tuned emission properties.A three-phase nanocomposite of sulfonated polyaniline embedded with such SWCNT/ZnO nanostructures has been prepared by a simple solution mixing chemical process and characterized by using high-resolution transmission electron microscopy,X-ray diffractometry,Raman spectroscopy,Fourier transform infrared spectroscopy,and thermogravimetric analysis.The study of UVvisible absorption and photoluminescence spectroscopies reveal that the ternary polymer nanocomposite is a luminescent material with enhanced emission intensity.Also an increase in DC conductivity indicates that the nanocomposite is also a good conductive material,satisfying Mott’s variable range hopping model for a two-dimensional conduction.Such a three-phase nanocomposite may find extensive application in dye-sensitized solar cells,sensors,and supercapacitors.展开更多
The polycrystalline Na_(2)SmV_(5)O_(15)(NSV),a new member of the tungsten bronze(TB)family,was prepared by a mixed-oxide technique.The room-temperature X-ray diffraction(XRD)confirmed the formation of single phase com...The polycrystalline Na_(2)SmV_(5)O_(15)(NSV),a new member of the tungsten bronze(TB)family,was prepared by a mixed-oxide technique.The room-temperature X-ray diffraction(XRD)confirmed the formation of single phase compound with orthorhombic crystal structure.The scanning electron microscopy(SEM)analysis indicated that the compound has homogeneous micrograph with a uniform distribution of small grains over the entire surface of the sample.The analysis of impedance spectra of NSV in a low-temperature range(-100℃to 100℃)at different frequencies exhibited interesting electrical properties like the contribution of bulk effect in conduction process.The study of imaginary part of the impedance at different temperatures showed existence of relaxation peak with its shift towards higher frequency on increasing temperature.This suggested the presence of frequency and temperature dependent relaxation process in the material.The loss peak spectra were found to abide by Arrhenius law with small activation energy of 0.12 eV.The temperature dependence of AC and DC electrical conductivity(σ_(AC) and σ_(DC))was also obtained.展开更多
An approximate solution to the problem of steady laminar flow of a viscous incompressible electrically conducting fluid over a stretching sheet is presented. The approach is based on the idea of stretching the variabl...An approximate solution to the problem of steady laminar flow of a viscous incompressible electrically conducting fluid over a stretching sheet is presented. The approach is based on the idea of stretching the variables of the flow problem and then using least squares method to minimize the residual of a differential equation. The effects of the magnetic field on the flow characteristics are demonstrated through numerical computations with different values of the Hartman number.展开更多
基金the University Grants Commission (UGC) Indiathe Council of Scientific and Industrial Research (CSIR) India Jadavpur University,India for providing the required support for the experiment
文摘The influence of single walled carbon nanotube（SWCNT）on the series resistanceof Rose Bengal（RB）and Methyl Red（MR）dye-based organic diodes has been studied.It has been revealed from experimental results that SWCNT has a significant effect on Rs.The values of Rs are measured from current–voltage（I–V）characteristics and also by utilizing the Cheung method.Obtained values from the Cheung method have been verified using H（I）–I plots for all dye-based devices.The extracted values using these two processes show a good consistency with each other.It is observed that Rs is reduced significantly by incorporating SWCNT for both dyes.The estimated amounts of reduction of Rs using SWCNT are 76.08%and 64.23%obtained from the I–V relationship whereas the value of Rs shows a reduction of 83.5%and 67.1%when measured by using the Cheung method for RB and MR dyes respectively.The ideality factor and barrier height of the diodes have also been extracted.The ideality factor has decreased with incorporation of SWCNT.A reduction in barrier height for the devices has also been observed in the presence of SWCNT.
文摘Functionalized single-walled carbon nanotubes(f-SWCNTs)hybridized with freshly prepared zinc oxide(ZnO)nanocrystals have been found to be good luminescent material with tuned emission properties.A three-phase nanocomposite of sulfonated polyaniline embedded with such SWCNT/ZnO nanostructures has been prepared by a simple solution mixing chemical process and characterized by using high-resolution transmission electron microscopy,X-ray diffractometry,Raman spectroscopy,Fourier transform infrared spectroscopy,and thermogravimetric analysis.The study of UVvisible absorption and photoluminescence spectroscopies reveal that the ternary polymer nanocomposite is a luminescent material with enhanced emission intensity.Also an increase in DC conductivity indicates that the nanocomposite is also a good conductive material,satisfying Mott’s variable range hopping model for a two-dimensional conduction.Such a three-phase nanocomposite may find extensive application in dye-sensitized solar cells,sensors,and supercapacitors.
文摘The polycrystalline Na_(2)SmV_(5)O_(15)(NSV),a new member of the tungsten bronze(TB)family,was prepared by a mixed-oxide technique.The room-temperature X-ray diffraction(XRD)confirmed the formation of single phase compound with orthorhombic crystal structure.The scanning electron microscopy(SEM)analysis indicated that the compound has homogeneous micrograph with a uniform distribution of small grains over the entire surface of the sample.The analysis of impedance spectra of NSV in a low-temperature range(-100℃to 100℃)at different frequencies exhibited interesting electrical properties like the contribution of bulk effect in conduction process.The study of imaginary part of the impedance at different temperatures showed existence of relaxation peak with its shift towards higher frequency on increasing temperature.This suggested the presence of frequency and temperature dependent relaxation process in the material.The loss peak spectra were found to abide by Arrhenius law with small activation energy of 0.12 eV.The temperature dependence of AC and DC electrical conductivity(σ_(AC) and σ_(DC))was also obtained.
文摘An approximate solution to the problem of steady laminar flow of a viscous incompressible electrically conducting fluid over a stretching sheet is presented. The approach is based on the idea of stretching the variables of the flow problem and then using least squares method to minimize the residual of a differential equation. The effects of the magnetic field on the flow characteristics are demonstrated through numerical computations with different values of the Hartman number.
