International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 04 Special Issue: 09 | Sep -2017
p-ISSN: 2395-0072
www.irjet.net
One Day International Seminar on Materials Science & Technology (ISMST 2017) 4th August 2017 Organized by
Department of Physics, Mother Teresa Women’s University, Kodaikanal, Tamilnadu, India
Role of rpm on the synthesis of Sol-Gel Derivate BSO Thin Films A.Amali Roselin1, N. Anandhan*1, M.Karthikeyan1, R. Priyatharshini1 1Advanced
Materials and Thin film Lab, Department of Physics, Alagappa University, Karakuri, Tamilnadu, India *Corresponding author email: anandhan_kn@rediffmail.com ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - In this work, we reported the synthesis of
Bismuth Silicate (Bi4Si3O12)(BSO) thin films on glass substrates by the sol-gel technique at different rpm 1500, 2000, 2500 and 3000 rpm for the 30s and annealed at 700ºC. The structural, optical, luminescence and morphological properties of the prepared thin films have been studied by X-ray Diffraction, UVVis spectroscopy, photoluminescence (PL) spectroscopy and SEM. XRD pattern of the films showed polycrystalline body centred cubic structure with (310) (321) plane growth orientation[1]. The absorbance of the film decreases with increasing wavelength and the transmittance was generally high in UV region. The energy band gap was found to be in the range of 3.54-3.75eV[2]. The thickness of the films decreases with increase in rpm. PL spectra of all the films are shown yellow emission at 575 nm under the excitation of 405 nm[3]. Surface morphology of the coated films was noticed by means of Scanning Electron Microscopic (SEM) technique. Key Words: Ferroelectric thin film, Bismuth silicate, Alkali earth metals
1.INTRODUCTION Bismuth silicon Bi12SiO20(BSO), belong to the selenite family, with the general formula Bi12MO20 where (M=Si, Ge, Ti, Pb, Mn, B1/2,P1/2). BSO is a stoichiometric selenite with a fully occupied oxygen sub lattice that meets all the major criteria for application as a low sintering temperature (Ts=850ºC)[1]. Among these, Bismuth silicate, Bi4Si3O12(BSO) has attracted a great deal of interest due to its excellent properties such as high hardness, large specific heat, small thermal expansion, high optical damage threshold, and high optical transmittance[2-5], good mechanical, thermal, electrical and electro-optical properties, it also exhibits good photoconductivity in the near ultraviolet spectral range[6]. The nonlinear optical characteristics of BSO have been used in a variety of applications, i.e., spatial light modulators, hologram recording devices and photorefractive incoherent-tocoherent optical converters [7-8]. Bi4Si3O12(BSO) scintillation crystal has potential use in medical imaging, high-energy nuclear physics experiments [9-11]. Recently, rare earth ion-doped bismuth silicate has been studied due to its excellent luminescent properties and potential application in white LEDs [12-15]. It has excellent prospects © 2017, IRJET
|
Impact Factor value: 5.181
|
as a luminescent substrate because of its special features and great chemical and physical stability [16-18]. Bi4Si3O12(BSO) thin films have already been successfully synthesized by chemical vapour deposition[19], pulsed laser deposition[20], dip coating method[21] and sol-gel process[22-24]. Among these, the sol-gel technique has many advantages over other synthesis techniques; such as excellent control over chemistry, homogeneity, purity and crystalline phase[25]. In this work, we report on the preparation of Bi4Si3O12(BSO) thin films using sol-gel spin coating technique and the effect of spin speed on structural, optical, luminescent and surface morphology of the prepared BSO thin films.
2.MATERIALS AND METHODS Synthesis of BSO (Bi4Si3O12) thin film by sol gel method deposited on glass substrates from a solution of bismuth nitrate using spin coating method. An appropriate amount of Bismuth nitrate was firstly dissolved in the 5 ml of acetic acid with a magnetic stirrer for 30mins, which was followed by the addition of 0.25 ml of Tetraethyl orthosilicate and 5 ml of 2-Methoxyethanol under constant stirring for 1h. The sol was then deposited onto glass substrates using the spin coating system. The spin speed has been varied in steps of 1500 rpm, 2000 rpm, 2500 rpm and 3000 rpm. Each layer was heated on pre-sintered for 30 mins at 250ºC for drying process in the closed furnace. These deposition and drying process was repeated 10 times to get the appropriate film thickness. Finally, all the deposited BSO thin films were subjected to annealing process at 700ºC for 2h to change amorphous to a crystalline structure. The prepared Bi4Si3O12 (BSO) thin films were subjected to XRD, UV-Visible, Photoluminescence and SEM analyses. The crystallites of the BSO thin films obtained by increasing spin speed were characterized by X-Ray Diffraction (XRD) using X’PERT PROX-ray diffractometer which was operated at 40 KV and 30 mA with CuKα1 radiation of wavelength 1.5407Aº. The thickness of the film has been measured using Stylus profilometer. Optical properties of the films were examined by UV-Visible and Photoluminescence Spectrophotometer. UV-Visible spectra were recorded in the range of 280-1100 nm by using Ocean optics HR 2000 spectrophotometer. The photoluminescence (PL) spectra were recorded using Varian ISO 9001:2008 Certified Journal
|
Page 1