Physics

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OPTIMIZING THE EFFICIENCY OF PEROVSKITE SOLAR CELL BY INCREASING THICKNESS AND TEMPERATURE
(DEPARTMENT OF PHYSICS KINNAIRD COLLEGE FOR WOMEN UNIVERSITY LAHORE,, 2023-05-17) ZAINAB FATIMA
The development of photovoltaic technologies have sparked significantly in last three decades. The major factor being low cost, more reliability and high efficiency. The simulation techniques used to minimize the size of devices are such as solar cells and to reduce the time for research period. Solar cells are the promising renewable resource that uses tri-valent and penta-valent compounds to achieve energy conversions. In this study the most extensively investigated perovskite methy-ammonium lead iodide (CH3NH3PBI3) is used as an active absorber layer and and the impact of thickness and temperature on their performances will be the main parameters to be studied. In this paper, SCAPS-1D will be used for the simulation process in order to study the parameters such as open-circuit voltage (Voc), short-circuit current (Jsc), Fill Factor (FF) % and Efficiency. This will be done by varying the thickness and temperature. The thickness is being varied from 100nm to 700nm and temperature will be varried from 300K-500K. As the thickness of CH3NH3PbI3 increases, decrease in open circuit voltage Voc, increase in the short circuit current Jsc will be observed. Also the increase of the efficiency and decrease of the Fill Factor (FF) will also be observed. Similarly, when the temperature is being varied by keeping the thickness constant for 700nm change in the parametric values will also be observed. As the temperature is increased there is a sudden drop in the efficiency of the solar cell. Also the short circuit current (Jsc), open circuit voltage (Voc) and Fill Factor (FF) decreased.
SIMULATION OF STRUCTURES AND POWDER DIFFRACTION PATTERNS OF α-𝐆𝐚𝟐𝐎𝟑AND β-𝐆𝐚𝟐𝐎𝟑
(DEPARTMENT OF PHYSICS KINNAIRD COLLEGE FOR WOMEN UNIVERSITY LAHORE,, 2023-05-17) FIZZA AFTAB
Silicon is approaching the peak of its performance, and basic limitations on its materials properties. A new oxide semiconducting material gallium oxide is a perfect material for the power devices in very high voltage applications. Ga2O3 has several crystalline forms, such as α, β, γ and δ phases, with different properties and applications. For example, the β Ga2O3, phase has a wider band gap compared to α phase and is suitable for UV optoelectronic devices. Fabrication and characterization of Ga2O3 based devices have been ongoing for several years, with recent breakthroughs in the growth of high-quality single crystal substrates and development of high-performance devices. Superior material properties of Gallium Oxide, especially a significantly larger band gap than those of Silicon Carbide and Gallium Nitride, aptitude power devices with higher Vbr and efficiency than Silicon Carbide and Gallium Nitride counterparts. Another significant feature of Ga2O3 is that instinctive substrates can be created from bulk single crystals grown using the same melt-growth procedures as sapphire substrates. In this research work, two of five polymorphs of Gallium Oxide are theoretically analyzed. From literature review, it was observed that the β phase exists as most stable polymorph. VESTA Software was used to achieve better understanding of different parameters in terms of crystal structures, XRD patterns, fractional coordinates and lattice planes for Ga2O3 α and β polymorphs. Challenges remain in the processing and scaling up of Ga2O3-based devices, as well as improving their efficiency and reliability. Overall, Ga2O3, is a favorable material for advanced power electronics, optoelectronics and sensing applications, and ongoing research is expected to lead to new breakthroughs and commercialization of Ga2O3-based devices soon
AB-INITIO STUDY OF SUPERIONIC CONDUCTORS
(DEPARTMENT OF PHYSICS KINNAIRD COLLEGE FOR WOMEN UNIVERSITY LAHORE,, 2023-05-17) MARZIA BATOOL
The use of halide materials as solid electrolytes has recently attained gigantic research interest due to their ability to operate at high temperature. Under over present knowledge novel halide electrolytes, such as LiYCl4, LiSmCl4, and LiAlCl4, exhibit high Li-ionic conductivities, approaching 10-3 S/cm, with low activation energies. A considerable experimental as well as theoretical efforts have been made in the identification of optimal combination of Li-M-X, (M: metal, X: halide) that are suitable at high temperature. Whereas, being a novel promising electrolyte material, LiAlCl4, there are not too many literatures available for the electronic, structural characteristics analysis of LiAlCl4. However, these characteristics decides the suitable battery material such as the materials with wide bandgap of ~ 6 eV are highly desirable. In this work, we employ Density Functional Theory (DFT) simulations to conduct a study of Li-M-X with M= Al and X =Cl. Electronic, structural properties and phase stability of LiAlCl4 is found. The values of the bandgap 5.63 eV and 5.2 eV are calculated by the exchange correlation functionals, Generalized Gradient Approximation (GGA) with Perdew-Burke-Ernzerhof (PBE) and the Local Density Approximation (LDA) for LiAlCl4, respectively. Results indicate that the GGA-PBE calculation gives a more desirable value closer to the experimental band gap. These results agree with the true nature of GGA-PBE method. On the other hand, experimental synthesis of electrolytes is time consuming and requires a lengthy process to achieve a perfect solid electrolyte. Computational modeling minimizes cost, time and complements experiments by providing unique theoretical insights to predict the state-of-the-art solid-state electrolytes, which have been rarely reported. Our calculations determined that LiAlCl4 shows promising potential as a battery electrolyte with a band gap of 5.63 eV, indicating the suitability of LiAlCl4 as a superionic conductor
COMPARATIVE STUDY OF ALUMINIUM DOPED ZINC OXIDE FOR PHOTOVOLTAIC CELL
(DEPARTMENT OF PHYSICS KINNAIRD COLLEGE FOR WOMEN UNIVERSITY LAHORE,, 2023-05-17) FATIMA EJAZ
Energy is an essential component of our daily life, and it is hard to imagine a day without it. The photovoltaic cell produces voltage or electric current by utilizing sunlight through the photovoltaic effect. While silicon photovoltaic (PV) cells grown on wafers have the disadvantage of being expensive and low in efficiency, thin-film (PV) cells technology is utilized for efficient energy production. Photovoltaic devices extensively utilize Aluminium-doped Zinc oxide thin films (AZO) due to their functionality of light transmission. This study investigated the thin film deposition on soda lime, borosilicate, and simple looking glass substrates using the Aluminium doped ZnO technique and radio frequency magnetron (RF) sputtering method, with a focus on sputtering power (W) on the optical properties of the films and structural analysis of the film. X-ray diffraction abbreviated as XRD and an Ultraviolet visible spectroscopy have been used to explore and analyze the Aluminium doped zinc oxide thin films. The observed diffraction peaks in all the AZO thin films were found to exhibit a hexagonal wurtzite crystal structure, with a predominant growth orientation forward the (0 0 2) plane and the c-axis perpendicular to the substrate, as evaluated through structural analysis. Transmittance measurements were conducted to gain the desired optical properties of thin films. It was discovered that film thickness had a significant impact on the optical band gap, with the band gap of samples 1, 2, and 3 increasing with the sputtering power (W). The optical band gap of aluminium doped zinc oxide increased with increasing sputtering power in the range of 30 to 500 W. The increase in sputtering power resulted in an increase in film thickness, leading to higher optical transparency and a widening of the band gap
THE COMPARATIVE STUDY OF MAGNETIC PROPERTIES OF ZINC DOPED NICKEL FERRITES AND COPPER DOPED NICKEL FERRITES PREPARED BY SOL-GEL METHOD
(DEPARTMENT OF ZOOLOGY KINNAIRD COLLEGE FOR WOMEN UNIVERSITY LAHORE,, 2023-05-17) AFFAF AMIR
Ferrite is a magnetic ceramic-like substance that can be used in a variety of electronic devices. Ferrites are polycrystalline that is, they are made up of many microscopic crystals they are tough, brittle, iron-rich, and often grey and black in color. They are formed by the combination of iron oxide with one or more metals. Magnetization refers to the concentration of magnetic dipole moment that appears in a magnetic substance when it is in proximity to a magnet. This research work includes the study and comparison of magnetic properties of Zn doped Ni ferrites and Cu doped Ni ferrites prepared using sol-gel method. At first Zn doped Ni ferrite samples were considered. Magnetic traits using vibrating sample magnetometer were inspected. Zn content with x=0, 0.3, 0.5, 0.7 and 1 were reviewed for magnetic parameters. Later, Cu doped Ni ferrite with values ranging from x= 0, 0.5, 1 were plotted. The M-H hysteresis curves of the samples reveal substantial increase in saturation and coercivity. These ferrites are utilized in implementation in engineering to make systems and improve their function.
A THEORETICAL STUDY OF METAL OXIDES
(KINNAIRE COLLEGE PHYSICS DEPARTMENT, 0022-06-22) ZAINAB NASIR
Crystallographic characteristics of different materials such as ZrO2 and 𝛼-Fe2O3 was theoretically analyzed. Modeling is the modern field of physics. Modeling comes in action for such conditions when it is either difficult or impossible to perform experiments and achieve particular conditions. Instead of directly performing experiments and taking measurements modeling is used as replacement. The goal of theoretical modelling is to make a particular aspect or an entire behavior of experimental evidences easier to grasp, characterize, simulate and visualize with eventually being able to forecast such behavior through the use of changing parameters. Transition metal oxide-based nanomaterials such as ZnO, Co3O4, RuO2, Fe2O3, ZrO2, MnO2, IrO2, V2O5, WO3 and In2O3 have attracted a lot of attention due to their capacity to interact with atoms, molecules and ions not just at their active surfaces but also throughout the material. In this research, metal oxide-based nanomaterials polymorphs ZrO2 and 𝛼-Fe2O3 crystal structures models were created such as wireframe, polyhedral, stick and space filling for enhanced perception by using VESTA software. VESTA tool is used to visualize fractional coordinates for 𝛼-Fe2O3 and ZrO2. By using VESTA software powder diffraction pattern (XRD) were also formed and gives most intense lattice planes (111) and (104) for ZrO2 and 𝛼-Fe2O3 respectively. Calculated bond length of zirconium Zr with oxygen O1 and O2 is 2.1070 Å and 2.2634 Å sequentially while on the other hand bond length between Iron Fe and oxygen O is 1.5400 Å. The bond length is calculated in angstrom. These transition metal oxide-based nanomaterials are used in the field of security, energy and environment
THE COMPARATIVE STUDY OF STRUCTURAL AND MAGNETIC PROPERTIES OF ZINC DOPED COBALT FERRITES
(KINNAIRE COLLEGE PHYSICS DEPARTMENT, 0022-06-22) NOOR-UL-AIN
Ferrite is a magnetic ceramic-like substance that can be used in a variety of electronic devices. Ferrites are polycrystalline and they are made up of many microscopic crystals they are tough, brittle, iron-rich, and often grey and black in color. They are made up of an iron oxide chemical combination and one or more other metals. Nanostructured cubic spinel ferrites with finely controlled nanostructures open up the possibility of developing nanomaterials with specialized characteristics for specific uses. In this research work the structural and magnetic properties of Zn doped Co ferrites were studied and compared. Firstly, the Zn doped Co ferrites prepared by sol-gel method were studied. X-ray diffraction of Co1- xZnxFe2O4 ferrite nanoparticles with x = 0.0, 0.1, 0.2, and 0.3, confirms the single phase cubic structure. Magnetic properties were investigated using the Vibrating Sample Magnetometer. The hysteresis curve of the samples reveals a considerable increase in magnetic properties. Also, the Zn-doped cobalt-ferrites with compositions of CoFe2xZnxO4 x=0.0, 0.1, 0.2, and 0.3, were synthesized by auto combustion method. The XRD analysis of the prepared powders showed irregular shaped grains morphology, as well as small impurity phases. These ferrites are used in electronic industry in order to make components and it is also used in security systems
EFFECT OF DIFFERENT BATTERIES ON BATTERY SYSTEM IN ELECTRIC VEHICLES
(KINNAIRE COLLEGE PHYSICS DEPARTMENT, 0022-06-22) MARIA ASFAR
COMPARATIVE STUDY OF ALUMINIUM DOPED ZINC OXIDE FOR ORGANIC LIGHT EMITTING DIODES (OLE
(KINNAIRD COLLEGE PHYSICS DEPARTMENT, 0022-06-22) MAHA JAVED
Technology has a significant impact on the electronics industry, causing it to become more creative and innovative in its production. Organic light-emitting diodes, or OLEDs, have transformed modern technology. We have studied that Aluminum doped zinc oxide tin coatings or thin films were produced by sputtering at various radio frequency power densities under argon gas pressure of 0.15 Pascal (Pa) to improve parameters at all for utilization for both in bottom emitting and transparent organic light emitting diodes. Therefore, the films have a wurtzite type hexagonal arrangement with 0002 preferential orientations and an optical transparency of more than 80 percent in the visible range, however the energy bandgap varies. Sputtering at a high radio frequency power density of 2.47 Wcm-2 produces Aluminium doped zinc oxide films with low resistivity and high work function, which are suitable for anodes in bottom emitting organic light emitting diodes. Al- doped ZnO films developed at a low radio frequency power density of 0.31 Wcm-2 , on the other hand, relate to a low work function with somewhat greater electrical resistivity and are therefore suitable for cathode in transparent organic LEDs. Hence, the equivalent performance of organic light emitting diodes made with Al-doped Zinc oxide and Indium tin oxide anodes confirms Aluminium doped zinc oxide applicability as an alternative electrode. We have studied that sol-gel method was used to create graded patterns of aluminum-doped zinc oxide or the AZO multilayered thin coating or thinner films on quartz glass substrate. To minimize stress, different Aluminium mol percent doped Zinc oxide graded topologies of multilayered thin films were developed. The tension between the layers was minimized by using graded multilayered thin films. X-ray diffraction abbreviated as XRD and an Ultraviolet visible spectrophotometer have been used to explore and analyze the graded constructions of multilayered Aluminium doped zinc oxide thin coatings or thin films. As a result, multilayered graded thin films of the thin coatings may be generated with less stress then crystallized or stabilized all along the c-axis. Thus, the optical transmittance of the films is about 94.8 percent at 400 nanometers to 800 vi nanometers wavelength and the energy band-gap is approximately 3.27 electron volts. The sol-gel method has important implications for creating trustworthy aluminium doped zinc oxide multilayer nanostructures or the thin film coatings with minimal strain-stress for device applications such as OLEDs. The sol-gel method was considered to be the most promising and appropriate method for the synthesis of Al-doped ZnO for device applications such as OLEDs

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