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Article
Laser-Controlled Photoluminescence Characteristics of Silicon Nanocrystallites Produced by Laser-Induced Etching

Author: B.G. Rasheed
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2005 Volume: 1 Issue: 1 Pages: 15-19
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In2O3 thin films have been deposited on silicon substrate by chemical spray pyrolysis. These films show high transparency in the visible and near-IR regions. Photoresponse of In2O3/c-Si isotype heterophotodiode without post-deposition heat treatment has been investigated in the visible and infrared regions. Peak response situated at 600nm was observed. External quantum efficiency was 32% at peak response. C-V measurements revealed that the junction was abrupt type and built-in potential around 1eV has been obtained.


Article
Electrical and Electronical Properties of Silicon Nanostructure Produced by Electronical Etching
الخصائص الكهربائية والالكترونية للسليكون ذو التركيب النانوي المحظر باستخدام طريقة التنميش الكمياوي

Authors: E. T. Saleem --- B. G. Rasheed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2009 Volume: 27 Issue: 14 Pages: 2523-2530
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Porous silicon constituting silicon nanostructures layer have been produce on crystal silicon using different preparation condition in electronical etching process. The electrical properties of the PS/c-Si heterojunction were studied and adopted to obtain the electronic structure and construct the energy band diagram of the device. This device could be used in various applications and was found to bea staggered type.

في هذا البحث، تم تحظير السليكون المسامي مشتملا على السلكون ذو التركيب النانوي على بلوره سليكون باستخدام شروط تحظير مختلفة. حيث تم استخدام تقنية التنميش الكهروكميائي من اجل تحضير طبقة السليكون المسامي، الازم من اجل الحصول على المفرق تم قياس الخصائص الالكترونية ووجدت لتكون معتمدا على مقدار تيار . (Ps/Si) الهجيني نوع التكوين وتم تحديد مخطط الطاقه للنبيطة المحظره. ان هذه النبيطه يمكن ان تسنخدم في مختلف التطبيقات ووجد ليكون من النوع الحاد.

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Article
Optical Properties of Silicon Nanoparticles Produced by Nd:YAG Laser Ablation

Authors: B.G. Rasheed --- M.A. Ibrahem
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2008 Volume: 4 Issue: 4 Pages: 19-23
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

Silicon nanoparticles films have been fabricated by laser ablation process using pulsed Nd:YAG laser. Various laser parameters were examined to produce films of different properties such as the laser energy, laser fluence, and the target-substrate distance. The experimental results have been fitted with the theoretical quantum confinement model to analyze the photoluminescence spectra and estimate the nanoparticle sizes and their distribution. From the optical transmission studies, we found that the band gap of the prepared nanostructured films was in the range (1.5-2.4)eV due to the existence of various nanoparticle sizes in the deposited film. Furthermore, the photoluminescence PL spectra indicate that the estimated band gap lies between (1.6-2.4)eV. While, the corresponding nanoparticle sizes contributing the PL emission were in the range (22-38)Å.


Article
Diffraction Grating and Periodic Surface on Porous Silicon
محزز الحيود والسطح الدوري للسيليكون المسامي

Authors: M. S. Mohammed --- B. G. Rasheed --- R. K. Soni
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2010 Volume: 28 Issue: 8 Pages: 1515-1524
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Fabrication of micrometer size laser-induced periodic surface structures (ripples)on single crystalline silicon by laser beam irradiation of wavelength (810 nm) in HFelectrolyte has been reported. Nonlinear changes of the refractive index are observeddue to the interaction of laser light with silicon nanoparticles. Spatial self-phasemodulated optical fringes were used to study the nonlinear optical response ofnanocrystalline silicon produced by laser-induced etching process.

تم تحضير سطح سليكوني مسامي ذو تركيب دوري متكرر باستخدام طريقة الليزر المحتث810 في حامض الهيدروفلوريك المركز. لوحظت التغيرات nm وذلك بواسطة التشعيع بطول موجياللاخطية لمعامل الانكسار من خلال تفاعل الليزر مع السليكمون النانوي. استخدمت اهداب التاخلالبصري المتظمنة للطور الذاتي الفضائي لدراسة الاستجابة البصرية اللاخطية للسليكون النانويالمنتج بعملية التنميش المحتث بالليزر.

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Article
Computation of Optical Energy Gap of Cu2O Thin Film: Theoretical Estimation

Authors: N.F. Habubi --- K.A. Mishjil --- H.G. Rashid --- B.G. Rasheed
Journal: Iraqi Journal of Applied Physics Letters الرسائل العراقية في الفيزياء التطبيقية ISSN: 1999656X Year: 2008 Volume: 1 Issue: 1 Pages: 21-23
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

Thin films of cuprous oxide Cu2O have been prepared using spraypyrolsis technique. Experimentally, the optical energy gap of Cu2O wasabout 2.2eV. To achieve and estimate an accurate Eg value, there wasproblem in the selection of exact tangent point. To overcome thisproblem, Newton-Raphson method and mean-value theorem were used.It was found that the mean-value theorem can predict correlated nearlysatisfactory Eg value than the other method.

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