Materials Research Innovations
ISSN: 1432-8917 (Print) 1433-075X (Online) Journal homepage: http://www.tandfonline.com/loi/ymri20
Structural and luminescent properties of PVA capped ZnSe nanoparticles Sk. Muntaz Begum, K. Ravindranadh, R. V. S. S. N. Ravikumar & M. C. Rao To cite this article: Sk. Muntaz Begum, K. Ravindranadh, R. V. S. S. N. Ravikumar & M. C. Rao (2018) Structural and luminescent properties of PVA capped ZnSe nanoparticles, Materials Research Innovations, 22:1, 37-42, DOI: 10.1080/14328917.2016.1265254 To link to this article: https://doi.org/10.1080/14328917.2016.1265254
Published online: 22 Dec 2016.
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Date: 14 December 2017, At: 04:09
Materials Research Innovations, 2018 VOL. 22, NO. 1, 37–42 https://doi.org/10.1080/14328917.2016.1265254
Structural and luminescent properties of PVA capped ZnSe nanoparticles Sk. Muntaz Beguma, K. Ravindranadhb , R. V. S. S. N. Ravikumarc and M. C. Raoa a
Department of Physics, Andhra Loyola College, Vijayawada, India; bPhysics Division, Department of Basic Sciences & Humanities, Chirala Engineering College, Chirala, India; cDepartment of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, India
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ABSTRACT
ZnSe nanoparticles are prepared by using chemical method in the occurrence of an optically transparent and semicrystalline polyvinyl alcohol polymer matrix. The prepared samples were characterised by different spectroscopic techniques like XRD, SEM with EDS, TEM, optical absorption, photoluminescence and FT-IR spectroscopic techniques. The average crystallite size was found to be 6 nm from the XRD pattern. The morphology of prepared sample was analysed by using SEM and TEM studies. Optical absorption spectrum exhibited the bands which were corresponds to pure ZnSe. Photoluminescence spectrum exhibits the emission band at 431 nm with the excitation wavelength of 350 nm. Functional groups of the prepared sample were observed in the FT-IR spectrum.
1. Introduction Great surface-to-volume ratio of nanoparticle semiconductors makes them possess properties that differ from the macroscopic semiconductors. Moreover, these properties depend mainly on their size and shape [1]. The II–VI semiconductor systems have many applications such as light emitting diodes and biological sensors [2]. While selenide semiconductors have considerable interest due to their important applications as thermo-electric cooling materials, laser materials, optical filters and sensors, super-ionic materials, optical recording materials, dispersion of quadratic non-linear susceptibilities and solar cells [3–5]. The optical properties of the semiconductors were found to be varied due to the effect of quantum confinement [6]. The inorganic–organic nanocomposites, mixed at molecular level or near molecular level, have attracted much attention due to their large potential applications in the field of optics, electrics, mechanics and photoconductors [7–9]. Semiconductor nanoparticles are currently being extensively studied due to their unique size dependent properties. It has been demonstrated by several groups that nanocrystalline II–VI semiconductors show enhanced luminescence, increased oscillator strength and shorter response time. The II–VI types of semiconductor nanoparticles represent ideal systems for dimension-dependent properties and have been extensively studied for their optoelectronic, photochemical and non-linear optical applications [10]. There is currently a great interest in II–VI semiconductor
CONTACT M. C. Rao
[email protected]
© 2016 Informa UK Limited, trading as Taylor & Francis Group
ARTICLE HISTORY
Received 27 May 2016 Accepted 5 September 2016 KEYWORDS
ZnSe; PVA; capping agent; crystallite size; SEM; TEM; optical and FT-IR
nanoparticles, particularly organically capped soluble particles or embedded in polymeric matrices for their ready to use application in devices [11–15]. Among these, Zinc selenide (ZnSe) material belongs to II–VI semiconductor with a direct bandgap of 2.7 eVat room temperature. Zinc Selenide is a wide bandgap semiconductor, which is advantageous for optoelectronics optical properties, particularly for light-emitting diodes and lasers working both in visible and infra-red regions of the spectrum [16]. There has been great interest to control the size of nanoparticles using surface capping agents. Polymers are able to achieve surface passivation, prevent particles from agglomeration which are in favour of controlling the particles size and size distribution effectively. The use of polymers is a prominent method for the synthesis of semiconductor nanoparticles. The reason is that the polymer matrices provide good processability and solubility. Polyvinyl alcohol (PVA) is a hydrophilic biodegradable, biocompatible, non-toxic, non-carcinogenic polymer. It is used in various pharmaceutical, medical, cosmetic, food and agricultural products [17]. PVA is an optically transparent polymer which is characterised by good chemical resistance and film forming ability [18]. In the present paper, we have discussed the spectroscopic and luminescent properties of ZnSe nanoparticles prepared by chemical method using PVA as capping agent. For the prepared sample the spectral characterisations like XRD, SEM with EDS, TEM, Optical, PL and FT-IR studies are carried out.
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as excitation sources. Bruker FT-IR spectrophotometer is used for recording the FT-IR spectrum in the region from 500 to 4000 cm−1.
3. Results and discussion 3.1. X-Ray diffraction studies
Figure 1. XRD pattern of PVA capped ZnSe nanoparticles.
2. Materials and methods
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2.1. Materials Zinc chloride (ZnCl2·5H2O), Sodium Hydrogen Selenide (NaHSe), PVA were used as starting materials and used without further purification. All the chemicals were of analytical grade and are used as received. Double distilled water was used as a solvent in the experiment. 2.2. Methods All steps of the synthesis were carried out at room temperature. At first, 0.054 g of Zinc chloride (ZnCl2) was added to 2.2 g PVA and volume of the solution is completed to 50 mL by double distilled water. The complete solution was left for 24 h at room temperature to swell. The solution was warmed up to 60 °C and stirred for 4 h until viscous transparent solution is obtained. One millilitre (mL) of Sodium Hydrogen Selenide (NaHSe) (50 mM) was dropped into the solution with gentle stirring to get transparent solution. The prepared solution was casted on flat glass plate dishes. After the solvent evaporation PVA capped ZnSe nanoparticles were obtained. The prepared film was washed with de-ionised water to remove other un-soluble salts before measurements. 2.3. Characterisation Using PAN Alytical X’Pert Pro X-ray diffractometer with CuKα radiation (1.5406 Å) source, X-ray diffraction pattern of the sample is recorded. Scanning electron microscope (SEM) and energy dispersive spectrum (EDS) images are taken on ZEISS EVO 18. Transmission electron microscope (TEM) images are recorded on HITACHI H-7600 and CCD CAMERA system AMTV-600 by dispersing samples in ethanol. The optical absorption spectrum is recorded using JASCO V-670 Spectrophotometer in the range from 400 to 900 nm. Photoluminescence spectrum is recorded on Horiba Jobin-Yvon Fluorolog-3 spectrofluorimeter with Xe continuous (450 W) and pulsed (35 W) lamps
XRD pattern of PVA capped ZnSe nanoparticles are shown in Figure 1. The diffraction pattern indicate a diffraction band around 2θ = 19.6° (19
