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 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 Investigations on Silicon Dioxide Nanostructures for the Applications of TOPCON Solar Cells(2022) Sidra Abdullah; CIIT/FA20-RPH-012/LHR; Dr. Shahzada Qamar Hussain; LHR TP 7974Silicon has been considered the best material for the fabrication of solar cells due to its non- toxicity, abundance, high and stable cell efficiencies, and industrial technological approaches. In this project, silicon dioxide (SiO2) based nanostructures were synthesized using a solution- based sol-gel technique. Spin coater was used to deposit the thin films of SiO2 on a glass substrate. The surface morphology of SiO2 nanostructures was measured by using a scanning electron microscope (SEM). The structural analysis of SiO2 nanostructures was studied via X- ray diffraction (XRD) analysis. UV-Vis spectrophotometers were used to measure the optical properties of SiO2 thin films. The simulation was used to study the influence of SiO2 and other layers on the TOPCON solar cellsItem Sol-Gel Synthesis of Copper Doped TiO2 Thin Films for Third Generation Solar Cells(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Muhammad Tariq; CIIT/SP20-RPH-026/LHR; Dr. Saif Ur Rehman; LHR TP 7690Dye-sensitized solar cells (DSSCs) have gained a great attention because they deliver good efficiency in power conversion, ease of manufacturing and lower costs, making them the most promising alternatives to traditional photovoltaic systems. DSSC photo-anodes were manufactured using nanostructures of undoped Titanium dioxide (TiO2) and Copper (Cu) doped TiO2 (CTO) in this study (2% and 4% concentration by wt. of Cu). The sol-gel process was utilized to synthesize these nanostructures. For materials analysis, Raman Spectroscopy, FTIR, UV-Visible (UV-Vis) spectrophotometer, EDS analysis, and scanning electron microscopy (SEM) were used to evaluate the material's properties, such as structural, optical, and morphological properties of prepared nanostructures. The FTIR spectra of three samples showed that intensity varied as we change the Cu concentration with TiO2. The peak intensity decreases in case of 2% and and 4% CTO. The Raman spectra of bare TiO2 and Cu doped TiO2 showed the shift in peaks, more intense peak is observed at 606cm-1 corresponding to A1g mode in TiO2. The lower peak is at 413cm-1 in case of 2% while in 4% CTO it is shifted to 404cm-1. SEM analysis revealed that doping of Cu with TiO2 increase the surface area of TiO2 nanoparticles and hence increase the conversion efficiency of cells. The average particle size of doped titania was observed about 60 nm. EDS analysis of the samples is done along with the SEM analysis to study the elemental composition of the samples. The EDS analysis of the bare andCu doped titania confirmed the synthesis of titania nanostructures and Cu doping. In UV-Visible analysis, the absorption improves with increasing Cu doping concentration, whereas the band gap decreases from 3.25 eV to 3.02 eV. The band gap value of undoped TiO2 is measured to be 3.25 eV, which was calculated using tauc plot. The band gap of 2% CTO was 3.17 eV, and of 4% CTO was measured as 3.02 eV. The solar cell device was fabricated, and solar simulations (J-V measurements) were performed, the photovoltaic parameters such as open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and efficiency (𝜂) were calculated. Simultaneous improvements in photovoltaic performance were achieved by Cu doping. In comparison with bare titania and 2% CTO, the 4% Cu doped TiO2 exhibits the higher efficiency (𝜂) of 1.76%.Item Fabrication and Characterization of TiO2/ZnO based Flexible Composite Films for Dye-Sensitized Solar Cells(2021) Ayesha Yasin; CIIT/SP19-RPH-036/LHR; Dr. Shahzada Qamar Hussain; LHR TP 7252Dye-sensitized solar cells (DSSCs) are considered as cost-effective photovoltaic devices due to their simple fabrication techniques. In this project, titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles were deposited on the Lignocelluloses (LC) fiber based flexible substrate. To begin, TiO2 nanoparticles were synthesized using the sol-gel method, whereas ZnO nanoparticles were synthesized using the microwave assisted approach. The scanning electron microscope (SEM) was used to examine the surface morphology of TiO2 and ZnO, while the atomic force microscope was used to examine the 3D profile and roughness (AFM). X-ray diffraction (X-Rays) analysis was used to examine the crystallinity and structure analysis of produced TiO2 and ZnO nanoparticles. A UV-Vis spectrophotometer was used to measure optical absorption. Dye-sensitized solar cells were fabricated on the deposited ZnO/TiO2/LC (the working electrode)Item Synthesis and Simulation study of Titanium Dioxide-Based Nanomaterial for Electron Carrier Selective Contact Solar Cells(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) JUNAID ASLAM; CIIT/SP19-RPH-035/LHR; Dr. Shahzada Qamar; LHR TP 7251Titanium dioxide-based nanomaterials were synthesized by utilizing the sol-gel process in this research. Due to the wide bandgap and low work function, TiO2 would easily replace the n-doped amorphous silicon (a-Si:H (n)) layer in commercial Silicon Heterojunction (SHJ) solar cells. Iso-Propanol Alcohol was used as sol while the Titanium Tetra Iso Propoxides was used as a gel. The TiO2 gel was formed and then dried for 2 hours at 300oC to obtain the powder form. After that, the TiO2 powder was dried for 3 hours in a furnace to obtain TiO2 nanomaterials. The TiO2powder was deposited on silicon and, glass substrate using the spin-coating process after successful production. Scanning Electron Microscope (SEM) and, X-ray diffraction (XRD) analysis were used to study the surface morphology and the structure of TiO2nanomaterials.Atomic Force Microscopy (AFM) was used to measure the roughness and, 3D profile, while absorption of the TiO2 based nanomaterials will be measured using a UV-Vs spectrophotometer. The AFORS-HET simulator was used to simulate electron carrier selective contact (CSC) solar cells for a complete photovoltaic device for various TiO2 thicknesses and, work functions.Item Study of Low Work Function-based Lithium Fluoride Nano-structures as Electron Carrier Selective Contact for Silicon Heterojunction Solar Cells(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Nauman Shafiq; SP19-RPH-009; Dr. Shahzada Qamar Hussain,; LHR TP 7250In this work, lithium fluoride nanostructures were synthesized by utilizing a wet chemical solution approach. LiFx is a viable option for replacing the n-doped amorphous silicon (a-Si: H(n)) layer in silicon heterojunction (SHJ) solar cells due to its low work function and wide-bandgap. A scanning electron microscope (SEM) was used to measure the surface morphology, while atomic force microscopy (AFM) was used to measure the 3D profile and roughness of LiFx nano-structures. The optical transmittance spectra of LiFx nano-structures were measured using a UV-Vis spectrometer. In addition, using various film thicknesses and LiFx work functions, simulated research for a complete photovoltaic device (electron carrier selective contact solar cell) was carried out.