Department of Physics
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Item Investigation of Doped (III-V) Group Elements Emissive Layer for Visible LED Applications(2019) Aqsa Hashmi; CIIT/FA17-RPH-043/LHR; Dr. Farah Alvi; LHR TP 5728This study Sb2S3 was prepared by applying hydrothermal technique with different concentration of Ag as a doping impurity to improve its optical and electrical properties to be used in optoelectronics for LED applications. FTIR spectra was used to analyze the vibrations of chemical bonds present in the different groups in the sample. The intensity of the peaks is reduced with the increase in doping concentration, this is because the strength of chemical bonds decreases because of intermolecular transition of groups present in the sample. Optical properties were studied by UV-Vis and PL spectroscopy. UV-vis spectra was used to calculate bandgap that comes out between 2.5-1.9 eV. The bandgap was reduced with the increase in doping concentration of Ag which indicate its good compatibility for LED applications. IV measurements were used to analyze IV characteristics of the samples and to find out the turn on voltage of the device. SEM results were helpful in analyzing the surface morphology of the samples and measuring the particle size. The device was characterized by electroluminescence spectra which confirmed the red emission from LEDs having emissive layers of undoped and doped Sb2S3. So the materials have bright future for visibe LED applications.Item Synthesis of Nickel Oxide (NiO) Fluorescence Nano Quencher and Their Application in Aptasensing of Ochratoxin-A(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) Aqsa Khan; FA17-RPH -042; Dr. Rizwan Raza; LHR TP 5727The fabrication of fluorescence based biosensor for the ultra-sensitive and selective monitoring of Ochratoxin-A in the food samples is very important these days. We demonstrate for the first time, the development of nickel oxide nanoparticles (NiO) quenching based aptasensing platform for the detection of target molecule (OTA). In this work, NiO quench the fluorescence of FAM-labeled aptamer. These quenched intensities were due to energy transfer processes to the metal nanoparticles. Conversely, increase in fluorescence quenching intensities with a decrease in the size of the nanoparticles which may be useful for the design of new analytical tool to detect the presence of target analyte. The structural properties of prepared nano materials were analyzed by X- Ray diffraction (XRD).Surface morphology of prepared metal oxide nano materials were studied by Scanning Electron Microscopy (SEM) and crystalline behaviors size/shape was analyzed by RAMAN spectroscopy. We have found the cost-effective, easy to use and affordable method to design aptamer based fluorescence quenching assay for the detection and early diagnoses of mycotoxins (OTA).Item Nanocomposites Anode Materials for Fuel Flexible Low Temperature Solid Oxide Fuel Cell(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) Muhammad Shakeel; FA17-RPH-061; Dr. Ghazanfar Abbas; LHR TP 5735Broad efforts have been made to create multi-fuel-based low temperature solid oxide fuel cell that will directly utilize hydrocarbons to produce electric power. It is very difficult to work because of the C-H bond activation and its immensely slow oxidation reduction in the low temperature range from 300 to 600 °C. The structural and electrochemical properties of prepared anode materials Ba0.15Zn0.60Mn0.15-Ag0.10, Ba0.15Zn0.60Mn0.15 Cu0.10,Ba0.15Zn0.60Mn0.15-Fe0.10, have been investigated within the sight of hydrogen, natural gas and ethanol at a low temperature of 650 0C. Through sol gel process prepared anode materials are synthesized. The average crystallite size has been found in the range of 19-90nm by XRD. Conductivity is measured by four probe method. Maximum conductivity of 4.8 S/cm, 4.3 S/cm and 4.4 S/cm have been found by using silver, copper, and iron as a catalyst at a temperature of 600 °C, 550 °C and 580 °C respectively. The impact of prepared nanocomposite materials on the performance of solid oxide fuel cell is investigated. The power density of the cell at different fuels has been checked and measurements demonstrate it varies from 100 to 500 mW/cm2 at 650 0C among different fuels at the anode side. The present examination reveals that proposed anodes are promising multi-fuel material for low-temperature solid oxide fuel cell, and it doesn't have to change hydrocarbon fills to completely use the benefit of these cells.Item Synthesis And Characterization Of Lead Based(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) Muhammad Faizan; CIIT/FA17-RPH-025/LHR; Dr. Muhammad Amir Razaq; LHR TP 5720To overcome the needs of energy the production and storage of energy has become the critical problem therefore most research topics around the world are related to the work on storage devices [1]. Lead acid batteries (LABs) are the most oldest among the secondary rechargeable batteries. The first lead acid battery was invented in 1859. In these days getting power for various applications from LABs has become a popular way. These batteries include two types of electrodes and an electrolyte. One of the electrodes is positive and the other is negative. The reaction between these components is the basic cause of the generation of power. Due to having fast response, high cyclic efficiency about (63-90%) and low cost these batteries playing a vital role in all type of industries [2, 3, 4, 5].Item Properties of Mesons by Variational Method(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Muhammad Irfan; CIIT/FA17-RPH-010/LHR; Dr. Nosheen Akbar; LHR TP 6065The study of mesons is very significant in particle physics. In this project I find the properties of mesons such as mass, radii etc. For this purpose, a suitable trial wave function is selected for calculating the energy of system. The trial wave function is selected so that the energy obtained by this approximate wave function becomes close to actual energy of the system.Item Green Synthesis, Characterizations and Photocatalytic Activity of ZnO Nanaoparticles Mediated via Okra Extract(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) TANZEEL IQBAL; CIIT/FA17-RPH-005/LHR; Dr. Muhammad Hammad Aziz; LHR TP 6064The progression of metal oxide nanomaterials through the green union convention has proven to be a leading tool in the application of nanotechnology especially as it is being used for drugs, biosensors, pharmaceuticals and water treatment. Nowadays, green chemical awareness has been observed in cell thinking, biosensors and drug delivery, the manufacture of Nano devices and the elimination of wastewater pollution. The synthesis of nanomaterials in raw form is unstable, unique biocompatibility, low cost and environmentally friendly. The aim of my research project is to find photocatalytic activity test technology with in-depth research into ZnO nanoparticles experiments linked to okra extract. Green synthesis ZnO will dramatically clarify the nanotechnology method using advanced technological instruments, for example, X-beam Diffraction (XRD), Field Emission Scanning Electron Microscope (SEM) and a visible UV spectrometer. This blue-green compound of ZnO nanoparticles will show the degradation of blue dye (MB) before sun exposure.Item Development of Flexible and Environmentally Safe Anodic Electrode Lead Acid Batteries(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Shahroz Khan; CIIT/FA17-RPH-032/LHR; Dr. Muhammad Aamir Razaq; LHR TP 6066In this era of advancement, world's most important commodity is increasing demand for green and reliable sources of energy. As traditional electricity networks are unable to meet these demands that is why world is moving towards green sustainable energy sources, as these sources are the only solution to tackle all these energy and environmental issues. Latest work in the domain of flexible electronics has set the high challenges for old energy sources. In this regard portable electronics like flexible and green energy conversion and storage devices has facilitated the mankind on the next level and still numerous doors are open for the researchers in energy sector. Lead dioxide is called the grandfather of all the coatings which are used to enhance the electrochemical properties of different metals. Lead dioxide based electrodes have high power density, discharge capacity about 140-230 mA h/g and high cycle life. Lead dioxide is being used as anodic electrode in lead acid batteries for hundred years ago. Lignocelluloses are very abundant on earth, incorporation of these natural fibers and textile fibers convert the rigid electrodes into flexible electrodes. These are very useful to meet the demand of flexible and environmental friendly technology for the modern age. This research shows that fabrication of lead dioxide with LC was successfully formed to report the lower chemical performance of direct deposition on LC and textile fibers. SEM Results gives the information about the surface morphology of a simple powder and composite with LC fibers. Addition of LC and textile fibers makes the working electrode flexible, low cost and environmentally friendly for flexible energy storage applications. Electrochemical measurements were performed i.e. cyclic voltammetry.Item Synthesis of LaFeO3 by Carbon Containing and Carbon free Precursors and Characterization(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Sufyan Ahmad; CIIT/FA17-RPH-038/LHR; Dr. Muhammad Idrees; LHR TP 6067In this work, Auto-combustion method and co-precipitation method is used to prepare LaFeO3. The Nano powder was successfully synthesized using chelating agent, precipitating agent and nitrates of iron and lanthanum. To explore the thermal growth of the crystalline phases, the as burnt sample and dry precipitates were kept in a furnace at 450oC, 600oC, 800oC and at 1000oC (in co-precipitation method) for four hours at each temperature. X-ray diffraction technique revealed that at temperature 450oC only the Fe (OH)3 and La (OH)3 were present there in powder dominantly in amorphous form. Increasing the treatment temperature caused the decomposition of these hydroxides into Fe2O3 and La2O3 accompanied by the formation of LaFeO3. The formation of LaFeO3 incomplete up to 800oC in Co-precipitation method and found crystalline LaFeO3 in combustion method at same temperature. LaFeO3 was obtained at 1000°C indicating that heating at 1000oC changes it into complete transformation of the oxides and hydroxides (of Fe and La) to LaFeO3 in co-precipitation method. For the sake of exploring the effect of variations in microstructure of samples prepared by precipitation method, the powder treated at 1000°C was pressed into several pellets of circular shape having the diameter of 10 mm and 1 mm thickness. The sintering temperature of the pellets was 1000oC selectively for 4, 8, 12 and 16 hours and were named as LF4, LF8, LF12 and LF16, respectively. Scanning electron microscopy (SEM) revealed that the particles possess spherical symmetry. The average grain size of LaFeO3 was found 200 nm and the grain size continue to grow by increasing the treatment time. The stability of carbonate residual precursors in combustion method has been explored by TGA. FTIR analysis of both method’s samples was done after treatment of heat at various temperatures. During heat treatment the continuous decomposition of these residuals occurred. The room temperature dielectric properties of LaFeO3 were analyzed and examined thoroughly at frequencies from 1 Hz to 10 MHz of both method’s samples and explored the effect of residual carbonate precursors on dielectric properties of combusted samples. The dielectric properties of combusted samples strongly affected by these amorphous carbonate residues. It was found that the value of dielectric constant improved wi th the rise in the t ime of heat t reatment . This increase in cryst al l ini ty shows higher value of di el ect ri c const ant .Item Study of Shock Waves Structures in the Comet Halley Plasma(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) Muhammad Abdul Ghani; CUI/FA17-RPH-014/LHR; Dr. Zahida Ehsan; LHR TP 5715Weak dust-acoustic waves (DAWs) are addressed in a nonthermal charge varying electronegative magnetized dusty plasmas with application to the Halley Comet. The dynamics of the nonlinear wave are governed by a Korteweg–de Vries Burger equation that possesses dispersive shock wave. A weakly nonlinear analysis is carried out to derive a Korteweg-de Vries-Burger equation. The weak magnetic field is responsible for the dispersive term, whereas nonsteady dust charge variation is responsible for dissipative term, i.e., the Burger term. The positive and negative ion nonthermality, the obliqueness, and magnitude of the magnetic field are found to modify the dispersive and dissipative properties of the DA shock structure. Our results may aid to explain and interpret the nonlinear oscillations that may occur in the Comet Halley Plasma.Item Oxygen Cyclotron Harmonic Waves in the Inner Magnetosphere(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) Abdul Waheed; CIIT/FA17-RPH-037/LHR; Dr. Muhammad Jamil; LHR TP 5726The Banded emission of Oxygen cyclotron harmonic waves has been observed by Van Allen probes in the Earth inner magnetosphere. The general dispersion relation for electrostatic Oxygen cyclotron harmonic waves is derived by using Lerche-Newberger sum rule for Maxwellian and Kappa distributions. Oxygen ion kappa spectral index (𝜅𝑖𝑂) has a significant impact on the Oxygen cyclotron harmonic waves. The quasi Maxwellian behavior is being observed as 𝜅𝑖𝑂 ≥ 5. The curves shift toward the higher value of wavenumber, as the value of 𝜅𝑖𝑂 reduce. There is an increase in super-thermal particles as we reduce the value of 𝜅𝑖𝑂. By decreasing the value of 𝜅𝑖𝑂, the super-thermal particles reduce the frequency , 𝜔𝑝𝑒𝑎𝑘, where the group velocity vanish and the associated 𝑘𝑝𝑒𝑎𝑘 get increase. These cyclotron harmonic waves may be useful for the diagnostic for the velocity distribution characteristics. Oxygen cyclotron harmonic waves can be helpful for the diagnostic of Van Allen Radiation Belts.