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The Effect of Annealing Temperature on Structural & Optical Properties of Nanocrystalline SnO2 Thin Films Prepared by Sol-Gel Technique

Authors: Selma M.H. AL-Jawad --- Abdulhussain K. Elttayf --- Amel S. Sabr
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 4 Part (B) Scientific Pages: 490-498
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this work, studying the structural and optical Nano crystalline SnO2 thin films grown on cleaned glass substrates by using sol- gel (dip coating) technique. It is worthy to say that the thickness of the deposited film was of the order of (300-400)nm . The films are annealed in air at , 300◦C, 400◦C and 500◦C temperatures for 60 minutes. The films that are analyses by X-ray diffraction (XRD), Scanning electron microscopy (SEM) , atomic force microscopy and optical absorption spectroscopy technique. The size of crystalline was observed, as well as, so as to increase with increasing annealing temperature . XRD analysis reveals that the whole films are polycrystalline with tetragonal structure with preferred orientation of (110),(101),(200) and (211) . The increase of annealing temperature leads to raise the diffraction peaks and decrease of FWHM. The atomic force microscopy (AFM) and Scanning electron microscopy (SEM) results showed that the average grain size was increase with the increase in annealing temperature. Spectra of transmittance and absorbance was recorded at wavelengths range (300-1000)nm .The optical properties showed high transmission at visible regions. The optical band gap energy was found to be (3.5 , 3.75 , 3,87) eV at annealing temperature (300,400,500 )°C respectively.


Article
Doping Effect on Structure, Optical, & Sensing Properties of Nanocrystalline (SnO2) Thin Films Prepared by Chemical Bath Deposition (CBD) Technique
تأثير التشويب على الخواص التركيبية , البصرية والتحسسية لأغشية ثنائي اوكسيد القصدير نانوية التبلور

Authors: Abdulhussain K. Elttayef عبدالحسين خضير الطيف --- Amel S. Sabr أمل ساجت صبر --- Selma M.H. AL-Jawad سلمى محمد حسين الجواد
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 5 Part (B) Scientific Pages: 186-197
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Thin films of Nanocrystalline Tin Oxide SnO2 and SnO2: Cu have been prepared on glass substrates using Chemical Bath Deposition (CBD) technique, The thickness of the deposited film was of the order of (300) nm . The films annealing in air at temperature 500◦C for 60 min .Structural, optical and sensing properties were studied under different preparation conditions like Cu-doping concentration (2%, 4% and 6%). These prepared films are polycrystalline with a tetragonal & orthorhombic crystal structure. The crystallinity and the particle size of the prepared samples were analyzed by X-ray diffraction (XRD), the results indicated the particle size of the prepared samples decreased with the increase of Cu doping concentrations some of the structure properties are changed by the addition Cu concentrations as dopants. The films are preferentially oriented along the (110) direction. We have got some surface morphology by Scanning Electron Microscopy (SEM), the results show decreasing of particle size with increasing doping concentration. The films have moderate optical transmission from (65% up to 88% at 800 nm), and the transmittance, absorption coefficient and energy gap were measured and calculated with Cu doping concentration. The results show that the doping caused to decreased the transmittance and energy gap from (3.55 to 3.8) eV while it caused to increase the absorption coefficient. It has also been found that Cu doped nanocrystalline SnO2 thin films gas sensing & recovery time material was presented a better sensitivity to CO gas compared to the pure SnO2.

في هذا البحث تم تحضير أغشية SnO2 غير المشوبة والمشوبة نانوية التبلور المرسبة على قواعد زجاجية بتقنية الترسيب بالحمام الكيميائي ، وان سمك الاغشية المحضرة بحدود ( 300 ) نانومتر ,لدنت الاغشية بدرجة حرارة بحدود ( 500 °C ) درجة مئوية في الهواء وبزمن ساعة واحدة. ودرست الخواص التركيبية والبصرية والتحسسية لاغشية ثنائي اوكسيد القصدير الغير مشوبة والمشوبة بالنحاس وبنسب تشويب % ) 2,4,and 6 ) . قد بينت نتائج فحوصات حيود الاشعة السينية ان جميع الاغشية المحضرة متعددة التبلور ومن الطور الرباعي والمع يني وباتجاهية سائدةبا تجاه ( 110 ( , وان زيادة نسبة التشويب ادى الى انخفاض في قمم الحيود وزيادة عرضها .كما واوضحت نتائج تحليل AFM و SEM ان متوسط الحجم الحب يبي قد تناقص بزيادة نسبة التشويب . سجل طيفا النفاذية والامتصاصية ضمن المدى ( 300-1000 ) نانومتر وقد تبين ان النفاذية وفجوة الطاقة البصرية انها تقل بزيادة نسبة التشويب حيث ان قلت من eV ) 3.8 to 3.55 ) بينما يزيادة معامل الامتصاص. وعند قياس تحسسيةالاغشية لغاز اول اوكسيد الكاربون تبين قيم التحسسية وزمن الرجوع لغاز اول اوكسيد الكاربون تزداد بازدياد نسب التشويبمقارنه بالاغشية النقية.

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