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Singh R.,Sharda University | Singh R.,Vishveshwarya Group of Institutions | Pandey S.P.,IIMT | Tomar S.K.,kshmipat University | And 2 more authors.
Nanoscience and Nanotechnology Letters | Year: 2014

Titanium Dioxide (TiO2 has been used as a working electrode of Dye sensitized solar cells (DSSC) for a long time. Their porous nature results in high surface area that ensures efficient light absorption. Apart from other advantages the porous nature of TiO2 results in a large number of surface states that trap carriers and promote recombination because of which efficiency goes down. In the present work, we have synthesized nanoparticles of PbS and develop a nanocomposite paste of TiO2-PbS. We have tested our nanocomposite paste for working electrode in DSSC. The samples were characterized using XRD, UV-VIS absorbance spectroscopy, FT-IR and SEM. PbS nanoparticles serve as surface state depressors, which reduces the surface states of TiO2 films. This further reduces recombination rate and increases the conversion efficiency of DSSC. The mechanism of charge transport on photovoltaic response and other parameters of the DSSC using PbS-TiO 2 nanocomposite are also presented in detail.© 2014 American Scientific Publishers All rights reserved.

Kumar A.,Amity University | Kumar V.,P.A. College | Suthar B.,Government Dungar College | Suthar B.,Government College of Engineering and Textile Technology , Berhampore | And 3 more authors.
IEEE Photonics Technology Letters | Year: 2013

Theoretical studies on the group velocity of light wave in 1-D polystyrene/SiO2 nonlinear photonic crystal is investigated. The speed of light wave through these multilayered structures is calculated in the absence as well as in the presence of a high intensity controlling wave by using the transfer matrix method. This letter shows that we can trap a light wave inside the nonlinear 1-D photonic crystal by switching off the controlling wave. © 2012 IEEE.

Kumar A.,Amity University | Suthar B.,Government College of Engineering and Textile Technology , Berhampore | Kumar V.,P.A. College | Bhargava A.,Government Dungar College | And 2 more authors.
Optik | Year: 2013

A tunable band pass filter with a linearly periodic refractive index profile analogous to the Kronig-Penny model of the band theory of solids is presented. The proposed filter is a one-dimensional periodic structure and the tuning of desired regions of wavelength is realized by varying the temperature and the angle of incidence. Here, we consider a Si/air multilayer system. In this present work, the refractive index of Si layer has been taken to be dependent on temperature and wavelength simultaneously. As the refractive index of Si layer is a function of temperature as well as the wavelength of the incident light, the structure can be used for the tuning of pass bands with the variation(s) of the temperature or the angle of incidence. © 2012 Elsevier GmbH.

Gupta M.,Krishna Institute of Engineering and Technology | Shukla M.,H.B.T.I. | Mishra S.,Mewar University | Kumar P.,I.I.M.T.
Proceedings - 4th International Conference on Computational Intelligence and Communication Networks, CICN 2012 | Year: 2012

Interleave Division Multiple Access (IDMA) is a recently proposed technique for multiple access of wireless communication. In this paper we have IDMA for Optical Fiber medium. In IDMA user specific interleaver are assigned to distinguish the various users. Thus, for good BER, low computational complexity, low bandwidth requirement interleaver should be designed cautiously. Although the performance of optical IDMA can be further improved by using various interleaving schemes. In this work the two interleaving scheme (Random Interleaver and Tree Base Interleaver) is compared in terms of computational complexity and memory requirement to store the interleaving sequences. © 2012 IEEE.

Kumar V.,P.A. College | Suthar B.,Government of Rajasthan | Kumar A.,Amity University | Singh K.S.,P.A. College | And 2 more authors.
Silicon | Year: 2014

The effect of temperature and angle of incidence on the transmission spectra of a one dimensional photonic crystal for TE and TM polarizations has been studied. For a range of angle of incidence from 0° to 60°, the proposed structure works as an omni-directional reflector. For other angles of incidence more than 60°, the structure works as a selective TM-polarization filter i.e. a filter which completely blocks TE-polarized waves but allows certain frequencies of TM-polarized waves. At an angle of incidence of 89°, the structure works as a multi channel optical filter without introducing any defect in the geometry. Also, this multi-channel filter can work as a tunable filter by varying the temperature of the structure and the number of layers in the geometry. Only for two bi-layers the proposed structure works as a single channel filter. Therefore, such types of structure are easier to fabricate and may be cost effective as compared to defect one-dimensional photonic crystals. © 2013 Springer Science+Business Media Dordrecht.

Kumar A.,Amity University | Kumar V.,P.A. College | Pandey G.N.,Amity University | Singh K.H.S.,P.A. College | Ojha S.P.,IIMT
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2013

Theoretical studies on the formation of gap soliton in one-dimensional negative Kerr nonlinear photonic crystal have been presented. Formation of gap soliton through the one dimensional photonic crystal has been studies for different intensities of controlling wave by solving Maxwell's electromagnetic equations and using transfer matrix method. The study shows that gap soliton form at high intensities of controlling wave and this property can be used to design optical switches.

Pandey G.N.,Amity University | Thapa K.B.,Chhatrapati Shahu Ji Maharaj University | Ojha S.P.,IIMT
Optik | Year: 2014

The omnidirectional reflection properties in one dimensional superconductor-dielectric photonic crystal have been studied theoretically. In this present communication, the superconductor-dielectric photonic crystal in one dimension having alternate regions of superconductor-dielectric. The reflectance behaviors from these periodic multilayered structures are calculated for different angles of incidence. The reflectance and band structure is obtained by solving a Maxwell's equation using a translational matrix method. The study of reflectance bands of such superconductor-dielectric photonic crystal show that it can be used as broad band reflector. © 2013 Elsevier GmbH.

Pandey G.N.,Amity University | Thapa K.B.,CSJM University | Ojha S.P.,I.I.M.T.
Optik | Year: 2013

In this paper the omni-directional reflection bands in one-dimensional plasma photonic crystal (PPC) have been studied theoretically. We present the study of plasma photonic crystal, having alternate regions of plasma-dielectric (Al2O3 or ZnS). Reflectances from this periodic multilayered structure in TE- and TM-modes are calculated for different angles of incidence in microwave region for omni-directional reflection bands. The reflectance is obtained by solving a Maxwell's equation using a translational matrix method. In addition to this, we have also studied the effect of variation of plasma width as well as plasma density on the reflection properties of plasma dielectric photonic crystal in TE- and TM-modes. The study of reflectance bands of such plasma photonic crystals shows that it can be used as omni-directional reflector. © 2012 Elsevier GmbH.

Kumar V.,Jv College | Kumar V.,Dj College | Kumar P.,Ms College | Kumar A.,Amity University | Ojha S.P.,IIMT
AIP Conference Proceedings | Year: 2013

A simple design of omni-directional reflector based on one dimensional superconductor-semiconductor photonic crystal has been proposed. The proposed structure consists of a periodic array of alternate layers of YBa 2Cu3O7 or YBCO (superconductor) and Si (semiconductor) as the materials of low and high refractive indices respectively. The refractive indices of YBCO and Si layers are taken as the function of temperature and wavelength both. Therefore, this study may be considered to be more physically realistic. The propagation characteristics of the proposed structure are analyzed by the transfer matrix method. © 2013 AIP Publishing LLC.

Shahi A.K.,University of Lucknow | Singh V.,Banaras Hindu University | Ojha S.P.,IIMT
Optik | Year: 2014

The theoretical analysis of two distorted doubly clad optical waveguides having plasma in inner cladding region have been presented. By matching the electric field and its derivative on the various interfaces, the dispersion characteristic equations have been derived and hence the cutoff frequencies are obtained. It is observed that the cutoff frequency of both considered cases are the function of plasma frequency and plasma width. Also, the plasma in the inner cladding region provides the extra degree of freedom to control the dispersion characteristics and one can trail the cutoff frequencies dynamically in time by playing with the discharge parameters associated with the plasma. © 2014 Elsevier GmbH. All rights reserved.

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