Department of Physics
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Item Fabrication of Metal Oxide Based Charge Transport Layer for Energy Conversion Devices(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Kainat Ishtiaq; CIIT/SP24-RPH-011/LHR; Dr. Ishrat Sultana; LHR TP 10123Energy conversion devices such as perovskite solar cells, dye-sensitized solar cells, and electrochemical energy storage systems have gained significant attention due to their potential to provide efficient, low-cost, and sustainable alternatives to conventional energy technologies. A critical factor influencing the performance of these devices is the charge transport layer, which governs charge extraction, transport, and recombination processes at the interfaces. In this study, nickel oxide (NiO) and zinc oxide (ZnO) were synthesized and investigated as hole transport and electron transport materials, respectively, along with their LC sheet–based composite counterparts, for application in energy conversion and storage devices. NiO and ZnO nanoparticles were successfully synthesized using a simple and cost-effective coprecipitation method, while LC sheet–based composites were developed using corn fiber as a sustainable carbon source to enhance electrical conductivity and interfacial contact. The structural, electrochemical, and vibrational properties of the prepared materials were systematically characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Raman spectroscopy. CV analysis revealed that pristine NiO and ZnO exhibited pseudocapacitive behavior due to reversible redox reactions, whereas LC sheet–based composites showed predominantly capacitive behavior with improved rate capability, reversibility, and charge–discharge performance. The enhanced electrochemical performance of the composites is attributed to the conductive carbon network provided by the LC sheet, which facilitates rapid electron transport and efficient ion diffusion.Item Synthesis of Biochar and Metal Based Working Electrode for Dye Sensitizer Solar Cell Application(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Memoona Zahoor; SP23-RPH-001; Dr. Ishrat Sultana; LHR TP 9624Banana peels are used as a preceding material in this investigation. It is dried, converted to bio Char, and then activated to generate activated carbon. Together with iron oxide, these components activated carbon powdered banana peel, and bio Char form a composite structure that aims to enhance the DSSC electrodes electro chemical characteristics. Because of its enormous surface area, porosity and conductivity, bio Char is a great substrate for introducing iron oxide nano particles. This improves DSSC stability and photo current production. According to the findings, the bio Char /iron oxide composite electrodes outperform pure bio Char and activated carbon electrodes in terms of power conversion efficiency and long-term stability. Through the efficient energy conversion of waste-derived materials for renewable energy technologies, this work presents a viable and cost-effective method for creating DSSC electrodes. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) are two material approaches that have been used to assess the electrodes structural or morphological properties. The different functional groups contained in the produced electrodes have been identified using Fourier transform infrared spectroscopy (FTIR). The band gap is determined via UV-Vis spectroscopy through a Tauc plate. J-V plots and efficiency calculations are provided by the solar simulator.Item Al Doped ZnO Nanomaterial For Solar Cell Application(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Attiya Afzal; CIIT/SP21-RPH-027/LHR; Dr. Ishrat Sultana; LHR TP 9998The energy problem is the most fascinating problem in this world because the way of success of every country is depending upon the development of low cast, well-ordered and high efficiency energy source devices. There are several research groups are working to develop the devices for renewable energy sources. So, we are going to focus our research on solar cells materials for renewable energy source like Zinc Oxide (ZnO). This material is highly useful for making the heterojunction solar cell as well as window layer. Other hand ZnO is used for 3rd generation/DSSC. In this direction we have synthesized zinc oxide (ZnO) nanoparticles by low- cost co-precipitation method without any surfactants. The synthesized ZnO nanoparticles have done the characterizations like X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) to evaluate shape, size, reproducibility and morphology of nanoparticles.Item Synthesis and Characterization of Nickel doped Zinc Oxide Based Paper Electrode for Dye- Sensitized Solar Cells(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2024) Maria Ejaz; CIIT/SP23-RPH-027/LHR; Dr. Ishrat Sultana; LHR TP 9644Flexible dye-sensitized solar cells (DSSCs) are a desirable alternative to rigid glass substrate-based solar cells because of the potential for flexibility and light weight. Researchers and scientists have been fascinated by polymer based electrodes due to its durability and flexibility. However, the production of polymers requires the use of hazardous chemicals. As a result, the tendency has shifted toward material synthesis methods that are safer, more affordable, and more sustainable. A flexible working electrode composite based on nickel (Ni) doped zinc oxide (ZnO) is synthesized in this project, by adding lignocellulose (LC) fibers. It is an effort to expand the potential of flexible electrodes based on metal oxide for DSSC applications. The co-precipitation process is used to create a transition metal-doped nanostructure (Ni doped ZnO). Doped particles with regulated composition, size, and homogeneity can be easily prepared at room temperature using this synthesis method. As a result, this work uses natural fibers to give Ni- doped ZnO a compact and porous structure for energy conversion applications. More sunlight will be absorbed as a result of the increased porosity, increasing the DSSC cell’s efficiency.Item 3D-printing of metallic nanoparticles via electrodeposition on paper based electrodes for energy storage application(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2023) Ammara Kanwal; CIIT/SP22-RPH-006/LHR; Dr. Ishrat SultanaA fresh method for handling the content develop variety of applications is provided by the ability of three-dimensional (3D) printing technology. Anisotropic in nature, molybdenum disulfide (MoS2) is a multilayer transition metal dichalcogenide (TMD). Its exceptional physio-chemical characteristics include a high carrier mobility, tunable band gap, large surface-to-volume ratio, unique electrical characteristic, friction, catalytic, and optical qualities. However, LC/MoS2 composites are synthesized by microwave assisted method. LC/MoS2 nanosheets electrodeposited by silver (Ag) and gold (Au) to enhance the electrical conductivity of LC/MoS2 substrate. The characterization performed for the properties of this composites include electrochemical analysis, FESEM, Raman & UV- vis spectroscopies. As a result, current density of 2 A g−1, the nanocomposite exhibits an impressive capacitive response of capacitance 9.1 F g−1. Absorption peak lies in the visible region with band gap of 1.9 eV. In summary, we have effectively combined the optical and electrical properties of the different components to create a unique composite that served as a useful platform for the advancement in energy storage applications.Item Extraction of Activated Carbon from Biomass for Energy Storage Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Farzana Bashir; CIIT/FA20-RPH-045/LHR; Dr. Ishrat Sultana; LHR TP 8001The current energy crisis is at its peak, and traditional energy sources are inadequate to supply modern energy demand. Consequently, the energy storage technology that can sustain current requirements is in high demand. Batteries and supercapacitor are examples of electrochemical energy storage devices (EESDs) that have been developed for a long time as crucial force sources in our daily lives. Orange peel, banana peel, wheat straw, olive stone, pistachio shells, walnut shells, beech wood, and hard coal, among other waste biomass sources, are used to produce activated carbon (AC). Activated carbon is used in energy storage applications due to high electrolyte wettability, high reactivity, and high thermal stability. Non- porous carbons are generated by the environmentally friendly, cheap, and low-temperature method of hydrothermal carbonization. For un-activated carbon we take 20 g of corn hair fiber and make gel in 100 ml DI water material was placed in autoclave at 250 ºC for 16 h. Activated carbon and KOH was taken by the ratio of 1:4 respectively, then grinding it in mortar and pestle, heated at 700-800 ºC at the 3 ºC min-1 ramp in a horizontal furnace under a nitrogen flow environment and held at this temperature for 1h. Hydrothermal process and temperature pyrolysis results in increased content of carbon and its aromatic nature in activated carbon. The percent yield of Activated carbon obtained through this method is much higher than other methods. Raman spectroscopy and Fourier transform infrared spectroscopy were used to evaluate the sample and approximate its composition. Cyclic voltammetry and electrochemical impedance spectroscopy were used to explore the sample's electrochemical properties. CV and Specific capacitance show the enhancement of conductivity. The material has the highest specific capacitance 235 Fg-1.Item Investigation on the Magnesium Fluoride as an Electron Carrier Selective Contact layer for Solar Cell Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Muhammad Zahid Seyal; CIIT/SP20-RPH-048/LHR; Dr. Ishrat Sultana; LHR TP 7696In this work, Magnesium Fluoride (MgF2) nanomaterials were synthesized by the microwave assisted method. Due to its high transparency, small refractive index and wide band gap would easily replace the amorphous silicon layer (a-Si:H(n)) in silicon heterojunction solar cells. Magnesium nitrate and ammonium fluoride was used for the synthesis of MgF2 nanomaterials. Optical absorptance spectra of the MgF2 films was measured by UV-Vis spectrophotometer. X- ray diffraction (XRD) and scanning electron microscopic (SEM) analysis were performed to characterize the structural and surface morphology of MgF2 nanomaterials. The Fourier transform infrared spectroscopic (FTIR) analysis was used to study the functional groups in MgF2 nanomaterials. Simulation study for the electron carrier selective contact solar cell device was performed for the thickness and work function variations of MgF2 layers.Item Optical and Electrochemical properties of MoS2 Based Doped Nanostructures for Renewable Energy Devices(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Imtisaal Hussain; CUI/SP20-RPH-062/LHR; Dr. Ishrat Sultana; LHR TP 7703To address the increasing energy demand at global level, renewable energy resources are the promising alternative of the hazardous fossil fuels and petroleum products which are also expected to run out in future. Renewable energy resources include thin film solar cells, fuel cells, supercapacitors, and batteries. Among these resources, thin film solar cells are considered to be an efficient energy resource due to abundant sunlight available in various parts of the earth. Solar cells convert sunlight to electrical power and therefore considered to be highly cost effective and can be manifested into flexible solar panels for a convenient installation and energy harvesting through electrochemical mechanism present within the cells. However, charge losses within the device owing to various factors limit the performance of these next generation devices and prevents them to set footing at commercial level. Many aspects of the device structure including working electrode, electrolyte and counter electrode play a crucial role in dictating the device performance. Among these components, counter electrode (CE) is of primary importance which acts as a catalytic agent for charge collection from the external circuit and provide it back to the working electrode for regeneration of the light absorber material coated on the working electrode. This, in return provides charges to the external circuit after absorbing suitable wavelength from the solar spectrum. The CE must have large surface area to provide more electroactive sites for charge transfer, efficient catalytic behavior to facilitate oxidation- reduction process in the cell, should be chemically stable, cost effective and environment friendly. This would prevent charge losses thus improving device efficiency. Molybdenum sulfide (MoS2) is a recently investigated 2-D material which has graphene like structure as well as efficient charge conducting properties. This material is widely employed in CE applications in thin film solar cells as it offers wide variety of possibilities to design a CE material which will exhibit all above mentioned merits.. However, due to inherent multi stacking of S-Mo-S layers, some of the electroactive sites are blocked which inhibit performance of the CE. This can be circumvented by synthesizing novel MoS2 nanocomposites and metal atom adsorption. Since the phenomenon dictating the availability of maximum electroactive sites for charge transfer, and chemical stability still needs to be fully understood, this necessitates developing new MoS2 based nanocomposites via ad-atoms and investigating their performance in CE based applications for thin film solar cells. In this work, metal doped MoS2 nanostructures is synthesized via facile wet chemical routes and studied as CE materials in prototype PV devices. The structural, morphological and electrochemical performance of the structures is analyzed by using Raman, PL and UV-Vis, and EIS characterization techniques.Item Synthesis, Characterization and Photocatalytic Performance of Modified Ag doped SnO2/ ZnO Nanocomposites(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Raja Zulqarnen; CIIT/SP20-RPH-007/LHR; Dr. Ishrat Sultana; LHR TP 7682Photo catalysis is low cost and environment friendly process for cleaning the water and removing organic pollutant. In our work, we employed a co-precipitation method to synthesize the silver doped tin oxide/Zinc Oxide Nano composites. This catalyst absorbs UV energy and in aqueous medium it degrades methylene blue dye. Scanning electron microscope (SEM) images were used to determine the surface morphology of Ag doped SnO2/ZnO. Characterization of the optical transmission (total and diffuse) was performed using FTIR analysis. XRD analysis was performed to determine the crystal structure. Raman analysis was used for the chemical structure of the NCs. In addition, photo catalytic activities were performed with the help of photo catalytic reactor chamber and UV spectroscopy for the degradation of the MB dyes.Item Fabrication of Green Template Based Flexible Electrodes for Hybrid Supercapacitors(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Asifa Iqbal; CIIT/FA20-RPH-030/LHR; LHR TP 7988; Dr. Ishrat SultanaFor rapid charging transfer and ion transport, multichannel-porous carbon generated from wood can act as a conductive substrate, supporting the high-theory capacitance of pseudocapacitive materials. High-performance supercapacitor electrode materials for NiCo2S4 nanosheets that are hierarchically porous and anchored on the surface of carbonized wood were proposed. The NiCo2S4 nanosheet accumulation was successfully reduced, and the hybrid wood-derived porous carbon-NiCo2S4 nanosheet material (NCS-CW) electrode displayed an 821 F g-1 specific capacity. We believe NCS-CW will be used as an electrode material that holds a lot of potential for energy storage devices because of its excellent electrochemical performance.