Physics

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Physics

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Start date: 2020

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    Chemically Deposited Doped Titanate Ternary Metal Oxide Thin Films Via Spray Pyrolysis Route-Preparation, Characterization and Solar Cell Application Analysis
    (4th Africa Nano Conference and Workshop, 2021-07) Eze, C. N.; Onyia, A. I; Nnabuchi, A. I
    Spray pyrolysis method of deposition is a simple, cheap, low cost and conventional method that gives uniform deposition. With this motivation, a simple approach of spraying ZnTiO3 nanoparticles on a substrate is reported. The approach occurs with ternary metal oxide and is environmentally friendly. This follows the quest to further improve the physical and chemical properties of ternary metal oxide which has become noticeable in recent times. The crystallization temperature of ZnTiO3 was 2000C. Among other investigations the SEM result shows a perovskite structure-like morphology. Further characterization performed on the thin film for the structural aspect which gives XRD of the thin film shown on the diffractogram is in agreement with the standard diffraction of ZnTiO3 which is identified as tetragonal structure. UV-Vis absorption spectroscopy was also used to characterize the final product and the spectra indicated that the absorbance obviously increased in the visible light region with absorption peak at about 209 nm and with optical band gap which infers that it has potential application in solar energy devices.
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    Surface Modification and Functionalization of Ceramic Composites.
    (Elsevier, 2023) Okeke, I. S; Obodo, R. M; Eze, C. N.; Orji, M. P; Agwu, K. K; Ubachukwu, A. A; Ezema, F. I
    Materials with high dielectric constants are essential in the control and advancement of electronics and electrical power systems. The dielectric properties of materials majorly include dielectric constants (ꜫo) and loss tangent (tan ẟ), and for a material to be considered a very good dielectric material, it needs greater ꜫo, lower tan ẟ and reduced leakage current (J). Inorganic mixed transition oxides (MTMOS) ceramics composites have shown huge potential than the transition metal oxide because they constitute two or more metal elements with different expansion coefficients that give rise to synergistic effects. MTMOs ceramics composites are mostly found with spinel structure such as normal spinel structure (NSS) and inverse spinel structure (IVS). Several synthesis techniques have been used in formulation of MTMOs ceramic composites. Their dielectric properties have been modified considerately by altering its morphology, use of modifying agent, and high calcination temperatures. In this chapter, we summarized MTMOs major structure type synthesis technique that have been successfully used in preparation of MTMOs, the dielectric properties of MTMOs and basis of surface modification in MTMOs as well as its effect in the dielectric properties.
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    The Role of Local Dyes in Dye-Doped Stannates and Titanates for Enhancement f Solar Energy Capture
    (FUDMA Journal of Sciences, 2025) Eze, C. N.
    Local dyes play a crucial role in enhancing solar energy capture in dye-doped stannates and titanates by acting as light-harvesting agents, boosting the efficiency of dye-sensitized solar cells (DSSCs). These dyes, when adsorbed onto the surfaces of porous semiconductor materials like TiO2, absorb incoming sunlight and then inject electrons into the semiconductor, initiating an electron transfer process that generates electricity. This process is similar to how plants capture sunlight in photosynthesis. Stannates and titanates, such as TiO2, ZnTiO3, BaSnO3 etc provide a porous surface for dye adsorption and act as the conductive material for electron transport. Their nanostructured surfaces increase the surface area available for dye adsorption, enhancing light capture.
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    Estimation of the Calorific Value and Electrical Energy Potential of Waste Generated Biomass Within Abakaliki Meteropolis Ebonyi State, Nigeria
    (American Journal of Nano Research and Applications, 2020) Igbo, M. E; Chikeleze, P. C; Onyia, A.I; Igbo, N. E; Eze, C. N.; Chima, A.I
    Abstract: This study was conducted to determine the electrical energy potential of municipal solid waste (MSW) generated biomass within Abakaliki metropolis, Ebonyi State, Nigeria. The MSW samples were collected at two different points from each of the waste management zones, with each zone covering at least twelve (12) streets. It was then sorted into three major categories according to their constituents viz; metals, plastics and biomass. In this study, the biomass component of the MSW sample was is our focus. Thus, the biomass sample was sun dried and then ground into powdered form. It was thoroughly mixed, shredded, sieved and subsequently analysed at the Lorcin Technologies Port Harcourt, Nigeria. Currently, an average of 360 tons of MSW is generated within Abakaliki metropolis on daily bases. This translates to an electrical energy potential of approximately 320MW. The MSW-generated biomass analysis estimates the Gross Calorific Value (GCV) or Higher Heating Values (HHV) to be 11.644MJ/kg. This value which practically determines the electrical energy of the waste sample is highly suitable for many thermal conversion processe. This translate to the fact 0.925kg of biomass will generate electrical power of 1KWh. Hence, one unit of electricity=10765KJ/Kg/GVC (KJ/Kg).
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    Bound state solutions of the generalized shifted Hulthén potential
    (Indian Journal of Physics Publishing model Hybrid, 2020-01-09) YUSUF Abubakar Sadiq; C. O. Edet; P. O. Okoi; P. O. Ushie; P. O. Amadi
    In this study, we obtain an approximate solution of the Schrödinger equation in arbitrary dimensions for the generalized shifted Hulthén potential model within the framework of the Nikiforov–Uvarov method. The bound state energy eigenvalues were computed, and the corresponding eigenfunction was also obtained. It is found that the numerical eigenvalues were in good agreement for all three approximations scheme used. Special cases were considered when the potential parameters were altered, resulting in Hulthén potential and Woods–Saxon Potential, respectively. Their energy eigenvalues expressions agreed with the already existing literature. A straightforward extension to the s-wave case for Hulthén potential and Woods–Saxon potential cases is also presented.
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    EFFECT OF ELECTRON TRANSPORT LAYERS, INTERFACE DEFECT DENSITY AND WORKING TEMPERATURE ON PEROVSKITE SOLAR CELLS USING SCAPS 1-D SOFTWARE
    (EAST EUROPEAN JOURNAL OF PHYSICS. 1. 332-341 (2024), 2023-12-30) YUSUF Abubakar Sadiq; A.M. Ramalan; A.A. Abubakar; I.K. Mohammed
    Perovskite solar cells have garnered significant attention from solar cell researchers due to their potential for achieving high efficiency, primarily attributed to their exceptional Electron Transport layer (ETL). One of the key elements of perovskite solar cells for transporting electrons to generate current is the ETL material. Moreover, there is a promising avenue for enhancing stability and reducing fabrication costs by substituting the transport layer. In this study, TiO2 and SnO2 were used as ETL materials in the architecture of perovskite solar cells for a comparative analysis between two devices featuring distinct structures: TiO2/CH3NH3PbI 3 /Spiro- OMeTAD and SnO 2/CH3NH3PbI 3/Spiro-OMeTAD. To evaluate the performance of each electron transport layer (ETL), the SCAPS 1D tool was employed. The investigation involved varying the thickness of the electron transport layers, interface defect density and working temperature, allowing for a comprehensive assessment of key parameters such as voltage at open circuit (Voc), short circuit current density (Jsc), fill factor (FF), and overall efficiency (PCE%). Remarkably, when employing SnO2 as the ETL, the achieved efficiency stands at 10.10 %. In contrast, utilizing TiO2 as the ETL yields a slightly higher efficiency of 12.84%. These findings underline the nuanced influence of transport layer materials on the overall performance of perovskite solar cells
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    Effect of Al Dope with ZnO Electron Transport Layer in Perovskite Solar Cells Using SCAPs 1-D Simulation
    (Nigerian Journal of Physics (NJP)ISSN online: 3027-0936ISSN print: 1595-0611, 2024-06-01) YUSUF Abubakar Sadiq; Ramalan, A. M; Abubakar, A. A; Mohammed,I.K; Ibrahim, S. O; Adamu, F. E; Ahmadu, U; Isah, K. U
    Perovskite solar cells have shown exceptional performance and significant advancements in solar cell efficiency. For perovskite solar cells to conduct electrons and generate current, one of the key components is the substance known as the electron transport layer (ETL). Using the SCAPS 1D modelling program, ZnO: Al was used in this instance as the ETL material in a perovskite solar cell. Because of its interaction with the perovskite material, the ZnO: Al ETL demonstrated high cell efficiency. The performance of the ZnO: Al-doped-based solar cell achieved a PCE as high as 23.5%. In the meanwhile, the greatest cell performance in terms of enhancing the charge transport mechanism and raising cell efficiency was shown by perovskite solar cells doping the ETL with Al and having the right layer thickness. Thus, throughout the manufacturing process, the parameters used in this study may serve as a guide.
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    A review of coating tin oxide electron transport layer for optimizing the performance of perovskite solar cells
    (Chemistry of Inorganic Materials Volume 6, August 2025, 100100, 2025-04-10) YUSUF Abubakar Sadiq; Ahmad Alhaji Abubakar; Isah Kimpa Mohammed; Umaru Ahmadu; Kasim Uthman Isah
    Perovskite solar cells (PSCs) have recently emerged as a transformative technology in the photovoltaic sector, drawing considerable attention due to their rapid advancements in power conversion efficiency (PCE), which now exceeds 26.7 %. This efficiency level places them in direct competition with conventional silicon-based solar cells. A key element in ensuring the high performance of PSCs is the charge transport layer (CTL), particularly the electron transport layer (ETL). The ETL plays a crucial role by efficiently collecting photo-generated electrons from the perovskite layer and transferring them to the transparent conductive oxide electrode. Among the ma- terials used for ETLs, tin oxide (SnO 2) stands out for its wide band gap, excellent optical transparency, superior carrier mobility, and remarkable chemical stability. Additionally, SnO2 can be deposited at low temperatures, making it ideal for mass production and adaptable for applications such as flexible devices. Despite its inherent advantages, the overall performance and quality of the ETL, and thus the device itself, are heavily influenced by the fabrication process. This study reviews recent approaches to fabricating SnO 2 ETLs in PSCs, with a focus on optimizing efficiency and long-term stability
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    Recycling potential of cathode ray tubes (CRTs) waste glasses based on Bi2O3 addition strategies
    (ELSEVIER, 2022) Al-Buriahi, M. S., Kavas, T., Kavaz, E., Kurtulus, R.,; OLARINOYE, OYELEKE
    Cathode-ray tubes (CRTs) from computer monitors and television sets are considered as one of the main sources of waste materials worldwide. Therefore, a new application for such out of use materials is required to solve the relatively huge amount of this waste. In this paper, the popular melt-quench technique was used to synthesis glass samples with the structure: xBi2O3–(100-x) waste CRTs (where x =0, 10 & 20 wt%) and designated as CRT- Bi0, CRT-Bi10, and CRT-Bi20 accordingly. The physical, structural, optical and radiation absorption competence of the glasses were investigated. The XRD analysis of the glasses reveals an amorphous structure while the mass density increased linearly with the Bi2O3 content of the glasses from 2.86 to 3.08 g/cm3. The optical absorbance of the glasses initially increased and later declined in the visible region as the weight fraction of Bi2O3 increased. The direct optical bandgap Eg values were found to be 3.26, 2.72, and 2.64 eV whereas the indirect Eg values were equal to 3.15, 2.30, and 2.26 eV for CRT-Bi0, CRT-Bi10, and CRT-Bi20, respectively. The gamma-ray interaction parameters of the glasses obtained through FLUKA simulations and XCOM computation showed that mass attenuation falls within the range 0.6991–0.0256, 1.1426–0.0276, 1.5860–0.0301 cm2/g for photon energy range 0.1–10 MeV. Generally, the computed gamma ray interaction quantities show that the gamma ray shielding ability of the CRT-Bi glasses follows the order: CRT-Bi0
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    Evaluation of radioactivity concentration of some selected mineral rocks from Mayo-Belwa Local Government Area of Adamawa State, Nigeria.
    (DUJOPAS, 2022) Oduh, I. O., Joseph, S. R.,; OLARINOYE, OYELEKE; Kolo, M. T.,
    Radiation from natural sources is constantly present around people and their surroundings. Natural Occurring Radioactive Materials (NORM) present in rock, soil and underground water are the major sources of this radiation. In this study, radioactivity concentration of 238U, 232Th, and 40K from Ten (10) different Granite (GN), Gneiss (GS), and Migmatite (MG) rocks samples obtained from Mayo Belwa Local Government Area of Adamawa State were evaluated using a well calibrated and shielded Canberra 3 x 3 inch NaI(Tl) detector at the National Institute of Radiation Protection and Research (NIRPR), University of Ibadan. Rock samples were cleaned, pulverised and placed in the detector for counting, and based on standard expressions, the radionuclide content of the granite rock samples were evaluated. The result shows that the activity concentration of 238U, 232Th, and 40K in GN samples varies from 62.44 – 117.67 Bq/kg, 76.59 – 165.58 Bq/kg, and 688.03 – 1472.42 Bq/kg with corresponding mean of 74.59 ± 3.12, 104.41 ± 3.12, and 950.16 ± 3.12 Bq/kg. Activity concentration of 238U, 232Th, and 40K in GS samples ranges from 19.23 – 36.49 Bq/kg, 29.06 – 49.42 Bq/kg, and 310 – 924.21 Bq/kg with corresponding mean of 28.1 ± 5.36Bq/kg, 38.92 ± 6.38 Bq/kg, and 664.21 ±178.14 Bq/kg. Activity concentration of 238U, 232Th, and 40K in MG samples ranges from 32.11 – 74.73 Bq/kg, 40.79 – 105.87 Bq/kg, and 453.34 – 1040.77 Bq/kg with corresponding mean of 50.19 ± 14.35 Bq/kg, 60.50 ± 19.96 Bq/kg, and 714.88 ± 200.37 Bq/kg. The mean activity from this study are higher than the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) global mean of 238U (32 Bq/kg), 232Th (45 Bq/kg), and 40K (420 Bq/kg) in soil and rock samples except for 238U and 232Th in GS samples which are lower than the recommended standards. The results signifies that usage of such rocks as building construction raw materials might pose radiological hazards in the long run. Therefore, mineral content of the rock responsible for the high radionuclide concentration should be investigated.