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Article
Preparation and Characterization Study of Porous Silicon Doped with Cu and Ag

Authors: U. M. Nayef --- A.M. Abdul Hussein --- A. J. Kata
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 1 Part (B) Scientific Pages: 8-12
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this paper, porous silicon was prepared by using electrochemical etching technique of p-type silicon acceptor, with a resistivity of 1.5-4Ohm.cm, using hydrochloric acid with concentration of 24%. The etching current density effect 4, 12, 20mA/cm2 was carried out at constant etching time of 15min. The structural characteristics of the porous silicon and the doped porous silicon were studied and found an expansion in the spectrum of the X-rays and a simple shift in the diffraction angles while maintaining the surface direction (111). The morphological properties were studied using the atomic force microscope which showed pores formation and gives the pore diameter within the range of 19.08 to 44.73nm for the prepared samples. It was also noted that the rate of pore diameter and the thickness of the porous silicon layer increased with increasing etching current density. Electrical characteristics of the nanoscale porous silicon layer and the doped porous silicon with silver and copper showed that Current-Voltage (I-V) characteristics of the prepared samples to be a rectifying behavior. An improvement in the electrical characteristics of the doped porous silicon samples was observed


Article
Study of the Influence of Incorporation of Gold Nanoparticles on the Modified Porous Silicon Sensor for Petroleum Gas Detection

Authors: A.M. Alwan --- A.B. Dheyab --- A.J. Allaa
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 8 Part (A) Engineering Pages: 811-815
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this work, the influence of alloying the porous surface with uniform distributed gold nanoparticles on the characteristic porous silicon gas sensors for petroleum gas detection has been fabricated and studied extensively. Well-controlled gold nanoparticles were prepared by employing the simple dipping process of the macro porous silicon surface in diluted concentrations of HAuCl4 salt aqueous solution. The sensing properties of the prepared porous silicon-based sensors, sensitivity response and recovery times at room temperature operating in CO gas were studied. The sensitivity of alloyed porous silicon increased from 38% to about 82% incorporation of gold nanoparticles. The lowest gas pressure detection process of CO molecules was improved from 1 mbar to 0.5 mbar. The surface alloying with rounded gold nanoparticles improved the integrated specific surface area of the alloyed porous silicon/gold nanoparticles structure, so efficient gas developed with the low-cost process.


Article
A study of kidney Parameters Induced by Porous Silicon Nanoparticles

Authors: K. H. Jwaid --- M. S. Jabir --- U. M. Nayef
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 2 Part (B) Scientific Pages: 150-153
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Nanoparticles are a special group of materials with unique features and extensive application in diverse fields .The present work demonstrates the toxicity effect of porous silicon nanoparticalse on kidney parameter which is prepared by electrochemical etching method. We conformed the synthesis of porous silicon nanoparticles by using structures and optical properties from through scanning electron microscope techniques and measuring absorbance of color. The study of toxicity effect of these nanoparticles on the kidney parameters in laboratory animals by used five groups was studied. Injected of porous silicon nanoparticles in the intraperitoneal at concentration of 1mgkg. The results of biochemical assay (urea and creatinine) compared with the control groups, for a period of four weeks was confirmed with Histology section of kidney. Our results showed that no significant differences in levels (urea and creatinine) between the test groups when compared with controls groups. This Results indicates no toxic effect of porous silicon nanoparticles in kidney parameters


Article
Synthesis and Study of Modified Nanostructure Porous Silicon Layers for Chemical Gas Sensing

Authors: A.D.Thamir --- A. L. Abed --- F. Q. Mohammed --- A. S. Hasan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 10 Part (A) Engineering Pages: 970-974
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this work, We prepared a modified nanostructure porous silicon (PS) layers for effective chemical gas sensing. Nanopore covered microporous silicon gas sensor has been fabricated using electrochemical etching in an HF acid and ethanol solution. A porous silicon (PS) surface has been modified using selective depositions formed from metal to enhance the response to Sensing of CO2. (PS) has been interest for gas sensing because of the exceptional gathering of importent features. By setting the process parameters,the porosity, pore size, and the morphology can be modifid and practically controlled. The modified porous silicon layers were characterized using different techniques such as scanning electron microscopy(SEM)and a series of electrical characterizations to study the structures in the contact of the carbon dioxide was achieved.


Article
Toxicity of Porous Silicon Nanoparticles on Liver of Mice

Author: Kareem H. Jwaid1
Journal: Al-Mustansiriyah Journal of Science مجلة علوم المستنصرية ISSN: 1814635X Year: 2017 Volume: 28 Issue: 3 Pages: 209-213
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Nanoparticles are a special group of materials with unique features and extensive application in diverse fields. The present work demonstrates the toxicity impact of porous silicon nanoparticles (PSNPs) on kidney parameter which is prepared by electrochemical etching method. the synthesis of porous silicon nanoparticles are conformed by using structural and optical properties from through scanning electron microscope and atomic force microscopy techniques. The effect of toxicity of these nanoparticles on the liver parameters in laboratory animals use four groups each groups involve three duplicities was studied. Injected of porous silicon nanoparticles in the intraperitoneal at concentration of 1mg/kg. The results of biochemical assay Aspartate Amino-Transferase (GOT), Alanine Amino-Transferase (GPT), Alkaline Phosphatase (ALP) were compared with the control groups, for four weeks and then confirm a result was made with Histological study for section of liver. Results show no significant differences in levels (GOT, GPT, ALT) among the test groups via comparison with controls groups. This Result indicates no toxic effect of porous silicon nanoparticles' on kidney parameters


Article
Synthesis of Al/OPS/PS/Si/Al by RTO and its detection properties

Journal: Journal of College of Education مجلة كلية التربية ISSN: 18120380 Year: 2017 Issue: 1 Pages: 129-138
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Porous silicon oxide (PSO) was prepared by rapid-thermal oxidization (RTO) of porous silicon that was formed on silicon substrate with optimum conditions. The porosity was approximately (65%) and layer thickness was (8μm). Photoluminescence (PL) observed a broad peak of porous silicon (PS) at 690 nm (1.79eV) with full width at half maximum (FWHM) of about 130 nm while the photoluminescence value of PSO located at 670 nm (1.85eV) with FWHM value of 140 nm. The lower values of resistances are 95.8 kΩ and 18kΩ of PSO and PS respectively. Response time of porous silicon detector about (9) second and the recovery time is about (6.5) second. The response time of UV detector for porous silicon oxide is (4) second and the recovery time about (8) second.The (PSO) sample exhibited high detection for incident ultra-violet (UV) light with and without bios

تم تحضير السليكون المسامي المؤكسد بطريقة التأكسد الحراري السريع للسليكون المسامي الذي حضرعلى شريحة من السليكون بشروط منتخبة. المسامية كانت تقريبا 65% وسمك الطبقة 8 مايكرومتر. التألق الضوئي للسليكون المسامي بين بأن له قمة عريضة عند 690 نانومتر (1.79 الكترون فولت ) مع اعلى شدة عند منتصف القمة 130 نانومتر بينما قياسات التألق الضوئي بالنسبة الى السليكون المسامي المؤكسد فبينت قمة عند 670 نانومتر (1.85 الكترون فولت ) مع اعلى شدة عند منتصف القمة 140 نانومتر. قياسات المقاومية للسليكون المسامي المؤكسد وللسليكون المسامي هي 95.8 و18 كيلو اوم على التعاقب. زمن الاستجابة لكاشف السليكون المسامي هو 9 ثانية وزمن الرجوع 6.5 ثانية بينما زمن الاستجابة لكاشف السليكون المسامي المؤكسد هو 4 ثانية وزمن الرجوع 8 ثانية. كاشف السليكون المسامي المؤكسد اظهر كشفية عالية للاشعة فوق البنفسجية مع او بدون انحياز.


Article
Porous silicon prepared by photo electrochemical etching assisted by laser
تحضير السليكون المسامي بالتنميش الكهروكيمياوي بمساعدة الليزر

Authors: Falah A-H Mutlak فلاح عبد الحسن مطلك --- Ahmed B. Taha احمد باسم طه
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2017 Volume: 15 Issue: 32 Pages: 122-129
Publisher: Baghdad University جامعة بغداد

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Abstract

Porous silicon (PS) layers are prepared by anodization for different etching current densities. The samples are then characterized the nanocrystalline porous silicon layer by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR). PS layers were formed on n-type Si wafer. Anodized electrically with a 20, 30, 40, 50 and 60 mA/cm2 current density for fixed 10 min etching times. XRD confirms the formation of porous silicon, the crystal size is reduced toward nanometric scale of the face centered cubic structure, and peak becomes a broader with increasing the current density. The AFM investigation shows the sponge like structure of PS at the lower current density porous begin to form on the crystalline silicon, when the current density increases, pores with maximum diameter are formed as observed all over the surface. FTIR spectroscopy shows a high density of silicon bonds, it is very sensitive to the surrounding ambient air, and it is possible to oxidation spontaneously.

في ھﺬا اﻟﺒﺤﺚ تم تحضير طبقات السيليكون المسامي التركيب بطريقة التنميش بالليزر لكثافات تيار مختلفة، ﺷﺨﺼﺖ ﺧﺼﺎﺋﺺ العينات المحضرة ﺑﻮاﺳﻄﺔ ﻓﺤﺺ ﺣﯿﻮد اﻷﺷﻌﺔ اﻟﺴﯿﻨﯿﺔ، ﻣﺠﮭﺮ اﻟﻘﻮة اﻟﺬرﯾﺔ، ﺗﺤﻮﯾﻞ ﻓﻮرﯾﺮ للأﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء حيث ان طبقات السيليكون المسامي تتكون على السطح حيث يتم تأينها بتيارات مختلفة (20, 30, 40, 50, 60 mA/cm2) لزمن تنميش .10 min من خلال فحص حيود الاشعة السينية يؤكد تكوين السيليكون المسامي وان الحجم البلوري يقل باتجاه الاحجام النانوية، ولوحظ ان القمة تزداد في العرض بزيادة تيار التنميش. من خلال مجهر القوة الذرية تبين ان عند التيارات الواطئة تبدأ طبقات السيليكون المسامي بالتكون وعند زيادة تيار التنميش سنحصل على اعرض قطر مسامي على السطح. من خلال تحويل فورير للأشعة تحت الحمراء تبين وجود أواصر كثيفة خاصة بالسيليكون حيث ان هذه الاواصر تكون قابلة للتأثر بالبيئة والهواء المحيط ويمكن ان تتأكسد باستمرار.


Article
Synthesis and Characterization of Au:CuO Nanocomposite by Laser Soldering on Porous Silicon for Photodetector

Authors: Juhaina Moatasemballah --- Halah H. Rashed
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2017 Volume: 20 Issue: 2 Pages: 49-59
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

This work aimed to the synthesize of composite Au:CuO (NPs) by pulsed laser soldering process. The optical properties, stability, structural properties and surface morphology of Au:CuO nanocomposite were characterized by UV–VIS spectrophotometer, Zeta potential measurement, X-Ray Diffraction pattern and Atomic Force Microscope respectively. The band gap of Au doped CuO is about 1.95 eV. The amount of zeta potential is -54 mV, its indicating that the negatively charged of Au: CuO nanocomposite in deionized water and the colloid is good stability against aggregation. Surface morphology of Au:CuO nanocomposite show a large number of particles have diameter about 55nm. Au: CuO nanocomposite deposited on porous silicon by drop casting technique for preparation of silicon photodetector, the electrical properties prove that band gap alignment between Au: CuO nanocomposite and PS facilitates the electron transfer and further increases the photoresponsitivity and Quantum efficiency.


Article
Porous Silicon Refractive Index Measurements with the Assistance of Two types of Lasers

Author: Saad A. Mohammed Salih
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2017 Volume: 20 Issue: 5 Pages: 1034-1039
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Porous Silicon (PSi) samples with (100) orientation n-type were prepared by photo-electrochemical etching process for different variable parameters and fixed electrolyte solution HF:C2H5OH:H2O (2:3:3). Physical and optical properties of PSi would be varied with the variation of process parameters such as current density, anodization time and laser wavelengths. Two types of 50 mW diode lasers were chosen, 473 nm Blue & 532 nm green at 20 mA/cm2 & 15 min etching time to assist the iodization process. The band gap of the fabricated layer has raised up to (2.9 eV) which is more than twice its original value for the c-Si (1.12 eV). Exploiting the obtained gap energy values, the refractive index of porous silicon layer was calculated depending upon Vandamme empirical relation. It was observed that the porosity is modifiable through etching conditions, which in turn makes refractive index also modifiable. Thus, the calculation depended on taking certain parameters as the current density and etching time in order to compare the effect of applying the two laser wavelengths. AFM was applied to observe the homogeneity and roughness of the PSi mono-layer. The results are in a very good agreement with the range of the refractive indices of PSi and the illumination with green laser gives a better conclusion to use in solar cells as a good absorber and a bad reflector.

تم تحضير عينات من السلكو ن المسامي على الوجه (n) من وجهي السلكون الخالص بعملية التنميش الضوئي-الكهروكيميائي اعتمادا على اعلومات متعددة وعلى ثبوت نسبة سائل التحلل الكهربائي بالمقدار ..HF:C2H5OH:H2O (2:3:3) .... تتغير الخواص الفيزيائية والضوئية للسلكون المسامي بتغير هذه الاعلومات مثل تغير كثافة التيار و زمن التحلل والاطوال الموجية لليزرات .في هذا البحث استعمل نوعان من الليزرات الدايودية ذوات 50 mW هما الليزر الازرق 473 nm والليزر الاخضر 532 nm وعند زمن التنميش المختار 15 دقيقة وكثافة تيار 20 mA/cm2 للمساعدة في انجاز التفاعل .ازدادت طاقة الفجوة للسلكون المسامي في بعض الحالات لاكثر من الضعف لتصل الى (2.9 eV) بدلا من 1.12 eV)) . تم استغلال طاقات الفجوة المستحصلة من تفاعل نوعي الليزراتالمطبقة لحساب معامل انكسار السلكون المسامي اعتمادا على العلاقة التجريبية للعالم (فاندام). لوحظ ان ان مسامية الطبقة تتغير بتغير اعلومات التفاعل وهذا بدوره يغير من قيم معامل الانكسار ولذلك فان الحسابات اعتمدت على تثبيت اعلومات التفاعل خاصة الكثافة الكهربائية كي تتسنى المقارنة بين افضلية الطولين الموجيين لليزرات المستعملة. طبق فحص PL وAFM على هذه النماذج لملاحظة مدى التجانس في مسامية طبقة السلكون ومدى خشونة سطحه اضافة الى مدى سمكه. اظهرت النتائج توافقا جيدا جدا مع مدى قيم معاملات انكسار السلكون المسامي المستنبطة بطرق اخرى وظهر ان افضل معامل انكسار لطبقة السلكون المسامي التي تقل معها نسبة انعكاس الضوء وزيادة نسبة امتصاصه في الخلية الشمسية هي عند تطبيق الليزر الاخضر .


Article
The effect of current density on the structures andphotoluminescence of n-type porous silicon
تاثير كثافة التيارعلى الخصاﺋص التركيبية وطيف اللمعان الضوﺋﻲ للسيليكون المسامي من النوع n

Authors: Nada K. Abbas ندى خضير عباس --- Isam M. Ibrahim عصام محمد ابراهيم --- Manal A. Saleh منال علي صالح
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2017 Volume: 15 Issue: 34 Pages: 15-28
Publisher: Baghdad University جامعة بغداد

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Abstract

Porous silicon (PS) layers were formed on n-type silicon (Si) wafers using Photo- electrochemical Etching technique (PEC) was used to produce porous silicon for n-type with orientation of (111). The effects of current density were investigated at: (10, 20, 30,40, and50) mA/cm2with etching time: 10min. X-ray diffraction studies showed distinct variations between the fresh silicon surface and the synthesized porous silicon. The maximumcrystal size of Porous Silicon is(33.9nm) and minimum is (2.6nm) The Atomic force microscopy (AFM) analysis andField Emission Scanning Electron Microscope (FESEM) were used to study the morphology of porous silicon layer. AFM results showed that root mean square (RMS) of roughness and the grain size of porous silicon decreased as etching current density increased and FESEM showed that a homogeneous pattern and confirms the formation of uniform porous silicon. The chemical bonding and structure were investigated by using Fourier transformation infrared spectroscopy (FTIR). The band gap of the samples obtained from photoluminescence (PL). These results showed that the band gap of porous silicon increase with increasing porosity.

ﺗﻢ ﺗﺸﻜﯿﻞ طﺒﻘﺎت اﻟﺴﯿﻠﻜﻮن اﻟﻤﺴﺎﻣﻲ ﻋﻠﻰ ﺷﺮاﺋﺢ اﻟﺴﯿﻠﻜﻮن ﻧﻮعn وذو اتجاهية (111) ﺑﺄﺳﺘﺨﺪام طﺮﯾﻘﺔ اﻟﻘﺸﻂ اﻟﻜﮭﺮوﻛﯿﻤﯿﺎئي ودراسة ﺗﺄﺛﯿﺮ أﺧﺘﻼف كثافة التيار (mA 10,20,30,40 and 50)ﻋﻠﻰ اﻟﺨﺼﺎﺋﺺ اﻟﺘﺮﻛﯿﺒﯿﺔ واﻟﺒﺼﺮﯾﮫ ﻟﻠﺴﯿﻠﻜﻮن اﻟﻤﺴﺎﻣﻲ وثبوت زمن القشط (10 ثواني). لقد اوضحت نتاﺋج حيود الاشعة السينية XRD ان طيف التركيب المسامي يختلف عن نظيره البلوري حيث كان اعلى حجم بلوري nm 33.9 واقل حجم بلوري 2.6 nm تم استخدام تقنية مجهر القوة الذرية AFM ودراسة طﺒﻮﻏﺮاﻓﯿﺔ السطح ﺑﺄﺳﺘﺨﺪام اﻟﻤﺠﮭﺮ اﻟﻤﺎﺳﺢ اﻷﻟﻜﺘﺮوﻧﻲFESEMحيث اوضحت نتائج AFMانمقدار الجذر التربيعي لمعدل خشونة السطح والحجم الحبيبي لسطح السيليكون المسامي قد يقل مع زيادة كثافة تيار التنميش. ان التركيب والتآصر الكيميائي للسيليكون المسامي تم فحصه بواسطة تقنية .FTIR اظهرت دراﺳﺔ طﯿﻒاﻟﻠﻤﻌﺎن اﻟﻀﻮﺋﻲ للسيليكون اﻟﻤﺴﺎﻣﻲ بان فجوة الطاقة للسيلكون المسامي تزداد بزيادة المسامية.

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