Physics
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Item Trend Analysis of Temperature in Gombe State Using Mann Kendall Trend Test(Journal of Scientific Research & Reports, 2018-10-11) YUSUF Abubakar Sadiq; U. U. Alhaji; C. O. Edet; Celestine O. Oche; E. P. AgboThis paper presents the trend analysis of temperature in Gombe State using Mann-Kendall trend test. The annual average of Maximum and Minimum Temperature data was obtained from the Nigerian Meteorological Agency (NIMET), Gombe State. In order to determine the nature of the trend and significance level, Mann-Kendall trend test and Sen’s estimate were employed. From this study, it was found out that Maximum and Average temperature exhibit positive Kendall’s Z value which indicates an upward trend and also imply increasing trend over time. The Test statistic ( ) for maximum and average temperatures are 4.38 and 4.43 respectively. This indicates that there is a significant increase in the trend at 5% level of significance since (p-values (0.0001) <0.05). However, the Z value for minimum temperature (1.59) shows a positive trend but not significant at 5% significant level since the p-value is greater than the significant level (p-value (0.107)>0.05). It can be inferred from both Mann- Kendall and Sen’s Slope that there is the tendency of increment in temperature. This could be due to the impact of climate change and can lead to weather extremes in the study area. It is therefore recommended that the variability of temperature should be monitored in order to minimize its effects on human activities.Item 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. AmadiIn 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.Item 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. MohammedPerovskite 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 cellsItem 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. UPerovskite 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.Item 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 IsahPerovskite 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