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Article
Effect of Laser Fluence on Structural Transformations and Photoluminescence Quenching of Zinc Selenide Nanoparticles Thin Films

Authors: Nadheer Jassim Mohammed --- Hala Adnan Ahmed
Journal: Al-Mustansiriyah Journal of Science مجلة علوم المستنصرية ISSN: 1814635X Year: 2018 Volume: 29 Issue: 4 Pages: 122-127
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

We reported in this work the growth of ZnSe nanoparticles thin films deposited on glass substrates were synthesized by a pulsed laser deposition (PLD) method. The as obtained films were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-VIS Spectrophotometer, and Photoluminescence (PL) spectra. X-ray diffraction study confirmed the transformation the cubic phase of ZnSe nanoparticles into hexagonal phase by increase the laser fluence from (4.77-5.97) J/cm2. The particle size variations were achieved by varying the laser fluence of prepared films. XRD studies and TEM images confirmed the nanometer size was found to lie in the range of 12-80 nm. A UV-VIS study was carried out to measure the band gap of the ZnSe nanoparicles thin films and it showed a blue shift with respect to the bulk value. The PL spectra at room temperature (300K) of the films showed the decrease of maximum values at at 522 nm( 2.379), 521 nm (2.3838) and 520 nm (2.3882 eV) for the laser fluences (4.77, 5.57 and 5.97 J/cm2), respectively. We assigned the variation due a larger number of non-radiative recombination centers appears in the films.


Article
Effect of deposition parameters on kinematics growth and optical properties of Fe2O3 nano films deposited by PLD.
تأثير معاملات الترسيب على حركية النمو والخواص البصرية لاغشية أوكسيد الحديد الثلاثي النانوية المرسبة بواسطة الترسيب الليزر النبضي.

Author: Suad Mahmood Kadhim
Journal: JOURNAL OF MADENAT ALELEM COLLEGE مجلة كلية مدينة العلم الجامعة ISSN: 2073,2295 Year: 2019 Volume: 11 Issue: 1 Pages: 103-116
Publisher: City College of Science University كلية مدينة العلم الجامعة

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Abstract

The optical and structural properties of Fe2O3 thin films deposited via pulsed laser deposition (PLD) have been studied. In PLD the energy of laser pulses was varied to investigate the properties of Fe2O3 thin films. In this work, different thickness of Fe2O3 thin film are deposited on glass substrates, namely, 63 nm, 110 nm and 189 nm.The structure of Fe2O3 thin films is investigated by the X-Ray diffraction, and it was formed to be polycrystalline structure. The XRD measurements show that these nano films have sharp peaks at 2θ =25º indicating a preferred orientation along (012) plane and the grain size (GS) increase with energy of laser pulses. The surface morphology of the deposited material has been tested via (SEM) gives good homogeneous films. According to the results, the nanoparticles GS and the thickness are ranging from (6.8 nm to 12.4 nm) and from (63 nm to 189 nm) is observed, respectively. The optical band gab of prepared films in range about (2.28-2.8eV).

الخلاصة:تم دراسة الخواص البصرية والتركيبية لاغشية اوكسيد الحديد الثلاثي المرسبة بواسطة الترسيب بالليزر النبضي. في الترسيب بالليزر النبضي كانت طاقة الليزر متنوعة لاستقصى الخواص البصرية لاغشية اوكسيد الحديد.في هذا العمل استخدمت اسماك مختلفة للاغشية (189-63) نانومتر.الخواص التركيبية لاغشية اوكسيد الحديد الثلاثي درست من خلال فحص حيود الاشعة السينية وبينت انها تملك تركيب متعدد التبلور.قياسات حيود الاشعة السينية بين ان الاغشية النانوية تمتلك قمم حادة عند زاوية مساوية º25 مشيرة لافضل اتجاه عند المستوي(012) وحجم حبيبي يزداد بزيادة طاقة الليزر. تشكيلية السطح تم اختبارها عن طريق المجهر الالكتروني الماسح واعطت الاغشية تجانس جيد. وفقا" لهذه النتائج فان الحجم الحبيبي والسمك بمعدل من (12.4-6.8) نانومتر و(189-63) نانومتر على التوالي. فجوة الطاقة البصرية للاغشية المحضرة فانها تتراوح من(2.8-2.28) الكترون فولت.

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