检索结果-南通市图书馆

A.C. Recombination Velocity as Applied to Determine n+/p/p+Silicon Solar Cell base Optimum Thickness

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and Power Engineering 2020年第10期12卷 543-554页

作者： Amadou Mar Ndiaye Sega Gueye Ousmane Sow Gora Diop Amadou mamour ba Mamadou Lamine ba Ibrahima Diatta Lemrabott Habiboullah Gregoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal University Institute of Technology University of Thiès Thiès Senegal Ecole Supérieure Polytechnique de Nouakchott Département Génie Electrique Nouackchott Mauritanie

This work deals with determining the optimum thickness of the base of an n+/p/p+ silicon solar cell under monochromatic illumination in frequency modulation. The continuity equation for the density of minority carriers generated in the base, by a monochromatic wavelength illumination (λ), with boundary conditions that impose recombination velocities (Sf) and (Sb) respectively at the junction and back surface, is resolved. The ac photocurrent is deduced and studied according to the recombination velocity at the junction, to extract the mathematical expressions of recombination velocity (Sb). By the graphic technique of comparing the two expressions obtained, depending on the thickness (H) of the base, for each frequency, the optimum thickness (Hopt) is obtained. It is then modeled according to the frequency, at the long wavelengths of the incident light. Thus, Hopt decreases due to the low relaxation time of minority carriers, when the frequency of modulation of incident light increases.

关键词： Silicon Solar Cell Modulation Frequency Recombination Velocity base Thickness Wavelength

base Thickness Optimization of a (n+-p-p+) Silicon Solar Cell in Static Mode under Irradiation of Charged Particles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Electromagnetic Analysis and Applications 2019年第10期11卷 173-185页

作者： Mamadou Lamine ba Ndeye Thiam Moustapha Thiame Youssou Traore Masse Samba Diop mamour ba Cheikh Tidiane Sarr Mamadou Wade Gregoire Sissoko Laboratory of Sciences and Techniques of Water and Environment Polytechnic School of Thiès Thiès Senegal Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal.

In this work, we propose a method to determinate the optimum thickness of a monofacial silicon solar cell under irradiation. The expressions of back surface recombination velocity depending the damage coefficient (kl) and irradiation energy (øp) are established. From their plots, base optimum thickness is deduced from the intercept points of the curves. The short-circuit currents Jsc0 and Jsc1 corresponding to the recombination velocity Sb0 and Sb1 are determinated and a correlation between the irradiation energy, the damage coefficient and optimum thickness of the base is established.

关键词： Silicon Solar Cell Irradiation Recombination Velocity base Thickness

Diffusion Coefficient at Resonance Frequency as Applied to n+/p/p+ Silicon Solar Cell Optimum base Thickness Determination

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Electromagnetic Analysis and Applications 2020年第10期12卷 145-158页

作者： Amadou Mar Ndiaye Sega Gueye Mame Faty Mbaye Fall Gora Diop Amadou mamour ba Mamadou Lamine ba Ibrahima Diatta Lemrabott Habiboullah Gregoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Ecole Polytechnique de Thiès Thiès Sénégal Département Génie Electrique Ecole Supérieure Polytechnique de Nouakchott Nouakchott Mauritanie

The modelling and determination of the geometric parameters of a solar cell are important data, which influence the evaluation of its performance under specific operating conditions, as well as its industrial development for a low cost. In this work, an n+/p/p+ crystalline silicon solar cell is studied under monochromatic illumination in modulation and placed in a constant magnetic field. The minority carriers’ diffusion coefficient (D(ω, B), in the (p) base leads to maximum values (Dmax) at resonance frequencies (ωr). These values are used in expressions of AC minority carriers recombination velocity (Sb(Dmax, H)) in the rear of the base, to extract the optimum thickness while solar cell is subjected to these specific conditions. Optimum thickness modelling relationships, depending respectively on Dmax, ωr and B, are then established, and will be data for industrial development of low-cost solar cells for specific use.

关键词： Silicon Solar Cell Resonance Frequency Magnetic Field Recombination Velocity base Thickness

back Surface Recombination Velocity Dependent of Absorption Coefficient as Applied to Determine base Optimum Thickness of an n+/p/p+ Silicon Solar Cell

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and Power Engineering 2020年第7期12卷 445-458页

作者： Meimouna Mint Sidi Dede Mamadou Lamine ba mamour Amadou ba Mor Ndiaye Sega Gueye El Hadj Sow Ibrahima Diatta Masse Samba Diop Mamadou Wade Gregoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Ecole Polytechnique de Thiès (EPT) Thiès Senegal

The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurrent. The absorption-generation-diffusion and recombination (bulk and surface) phenomena are taken into account in the excess minority carrier continuity equation. The solution of this equation gives the photocurrent according to absorption and electronic parameters. Then from the obtained short circuit photocurrent expression, excess minority carrier back surface recombination velocity is determined, function of the monochromatic absorption coefficient at a given wavelength. This latter plotted versus base thickness yields the optimum thickness of an n+-p-p+ solar cell, for each wavelength, which is in the range close to the energy band gap of the silicon material. This study provides a tool for improvement solar cell manufacture processes, through the mathematical relationship obtained from the thickness limit according to the absorption coefficient that allows base width optimization.

关键词： Silicon Solar Cell Absorption Coefficient back Surface Recombination Optimum Thickness

Influence of Both Magnetic Field and Temperature on Silicon Solar Cell base Optimum Thickness Determination

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Physics 2019年第13期10卷 1596-1605页

作者： Nouh Mohamed Moctar Ould Mohamed Ousmane Sow Sega Gueye Youssou Traore Ibrahima Diatta Amary Thiam mamour Amadou ba Richard Mane Ibrahima Ly Gregoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal University Institute of Technology University of Thiès Thiès Sénégal Ecole Polytechnique de Thiès Thiès Sénégal

The minority carrier’s recombination velocity at the junction and at the back surface is used for the modeling and determination of the optimum thickness of the base of a silicon solar cell in the static regime, under magnetic field and temperature influence. This study takes into account the Umklapp process and the Lorentz effect on the minority carriers photogenerated in the base.

关键词： Silicon Solar Cell Diffusion Coefficient Surface Recombination Velocity Optimum base Thickness Lorentz and Umklapp Processes

Assessment of a Database Management System in a Mammogram Unit of a Radiologic Department in Fann Teaching Hospital (Senegal)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2017年第4期6卷 401-409页

作者： mamour Gueye Awa Sadikh badiane Sokhna ba Diop Mamadou Ly Mame Diarra Ndiaye Gueye Abdoulaye Dione Diop Abdoulaye Ndoye Diop Marame Fall Gynecologic and Obstetric Clinic Aristide Le Dantec Teaching Hospital Dakar Senegal Department or Radiology Fann Teaching Hospital Dakar Senegal

Objectives: To evaluate a medical data management system of a mammogram unit in a department of Radiology. Methods: This is a qualitative and quantitative assessment study in Fann Teaching Hospital between April 2014 and June 2015 one year after its implementation. The quantitative component consisted of the audit of the database to determine the socio-demographic characteristics of patients and the results of mammograms. The qualitative component assessed users’ experience. For analysis, quantitative data were extracted and transferred to Microsoft Excel. For scale variables, we calculated the averages and extremes. For qualitative variables, we established percentages. Results: During the study period, 433 patients underwent mammograms. The average age of patients was 48 years. The completion rate maintained above 85% was below 26% in the first two months of use. As to the completeness given examinations, it was still above 83%. The results of mammogram examinations were normal in the majority of cases: 96% for the right breast and 95.2% for the left breast. All users had a favourable opinion about the database. The reasons were better work organization, comprehensiveness, accessibility and standardization of information about the patient and especially the immediate availability of statistics. For 60% of these health professionals, complaints related to the use of the software were the time-consuming of filling data. Conclusion: This study mainly describes the perception of health professionals on the computerization of radiological examinations. It offers some advantages, proposes improvements and opens avenues for reflection on the globalization of the computerization of patient records in Radiology.

关键词： Electronic Medical Records Database Mammogram Radiology Dakar