Multi-Layer Microstructure of Sol-Gel Barium Titanate Thin Films for Optical Waveguide Applications

2015 ◽  
Vol 815 ◽  
pp. 136-140
Author(s):  
S.H. Najamudin ◽  
H.Mohd Yusof ◽  
Ala’eddin A. Saif ◽  
R.A. Osman ◽  
P. Poopalan

— Barium titanate (BaTiO3) thin films are suitable for many application especially photonics. BaTiO3thin films are deposited using spin coating with an optimum spin speed of 4500rpm. The samples are then characterized using XRD, AFM and SEM. The results of the XRD analysis showed that both the 5-and 10-coated layers are polycrystalline BaTiO3with differences in terms of diffraction intensity, due to the number of layers. As for optical application, the surface roughness is the most crucial part. The number of layers of 5 and 10 have thickness of 2.927nm and 4.456nm RMS.

2013 ◽  
Vol 594-595 ◽  
pp. 113-117 ◽  
Author(s):  
Dewi Suriyani Che Halin ◽  
Ibrahim Abu Talib ◽  
Abdul Razak Daud ◽  
Muhammad Azmi Abdul Hamid

Copper oxide films were prepared via sol-gel like spin coating starting from methanolic solutions of cupric chloride onto the TiO2 substrates. Films were obtained by spin coating under room conditions (temperature, 25-30 °C) and were subsequently annealed at different temperatures (200-400 °C) in oxidizing (air) and inert (N2) atmospheres. X-ray diffraction (XRD) patterns showed crystalline phases, which were observed as a function of the annealing conditions. The film composition resulted single or multi-phasic depending on both temperature and atmosphere. The grain size of film was measured using scanning electron microscopy (SEM) and the surface roughness of thin films was characterized by atomic force microscopy (AFM). The grain size of which was annealed in air at 300 °C was 30.39 nm with the surface roughness of 96.16 nm. The effects of annealing atmosphere on the structure and morphology of copper oxide thin films are reported.


2021 ◽  
Vol 63 (8) ◽  
pp. 778-782
Author(s):  
Tülay Yıldız ◽  
Nida Katı ◽  
Kadriye Yalçın

Abstract In this study, undoped semiconductor ZnO thin film and Bi-doped ZnO thin films were produced using the sol-gel spin coating method. By changing each parameter of the spin coating method, the best conditions for the formation of the film were determined via the trial and error method. When the appropriate parameter was found, the specified parameter was applied for each film. The structural, superficial, and optical properties of the films produced were characterized via atomic force microscope (AFM), UV-visible spectroscopy, and Fourier transform infrared (FTIR), and the effects of Bi dopant on these properties were investigated. When the morphological properties of the undoped and Bi-doped ZnO films were examined, it was observed that they had a structure in a micro-fiber shape consisting of nanoparticles. When the surface roughness was examined, it was observed that the surface roughness values became larger as the rate of Bi dopant increased. By examining the optical properties of the films, it was determined that they were direct band transition materials and Bi-doped thin films were involved in the semiconductor range. In addition, optical properties changed positively with Bi dopant. Since Bi-doped ZnO thin film has a wide bandgap and good optical properties, it is a material that can be used in optoelectronic applications.


2016 ◽  
Vol 694 ◽  
pp. 120-124 ◽  
Author(s):  
Nurul Azuwa Azmi ◽  
Umar Al Amani Azlan ◽  
Maziati Akmal Mohd Hatta ◽  
Mohd Asyadi' Azam Mohd Abid ◽  
Mohd Warikh Ab Rashid

(K, Na)NbO3 (KNN) thin films were prepared by sol-gel technique. Spin coating deposition and rapid thermal annealing (RTP) process were applied to produce the KNN thin films. The films obtained demonstrated that highly crystallographic orientation was produced at five layer deposition with increase (preferred orientation) peak at (1 1 1). The thickness of five layers thin films observed by field emission scanning electron microscopy (FE-SEM) was determined to be ~200nm. However, the inhomogeneous distribution of KNN particles was detected in KNN thin films. The distribution of KNN elements was confirmed by energy-dispersive X-ray (EDX) spectra. Improvement was observed in resistivity (2.71-7.81x106 Ω.cm) and dielectric loss (0.35%-0.21%) following the increasing number of layers.


2013 ◽  
Vol 701 ◽  
pp. 167-171 ◽  
Author(s):  
Kevin Alvin Eswar ◽  
Azlinda Ab Azlinda ◽  
F.S. Husairi ◽  
M. Rusop ◽  
Saifollah Abdullah

Zinc acetate dehydrate as starting material along with diethanolamine as stabilizer, and isopropyl as a solvent were used to synthesis ZnO thin films in different low molarities. Sol-gel spin coating method was used in depositing ZnO on porous silicon substrate surface. In other to prepare substrate, p-type silicon wafer was etched by dilute hydrofluoric acid to modify the surface becomes porous. Field Emission Scanning Electron Microscopy (FESEM) was employed to study the surface morphology. It is found that ZnO thin films were successfully deposited on the substrates which are composed of ZnO nanoparticles with size ~16 nm to ~22nm. Atomic Force Microscopy (AFM) was used to investigate the surface roughness of thin film. The result shows that the surface roughness is increase as the increases of molarities. Photoluminescence (PL) spectra were done in range of 350 nm to 800 nm. The result shows peaks belonging to ZnO, ZnO defects, and porous silicon respectively are appeared.


2012 ◽  
Vol 528 ◽  
pp. 249-253
Author(s):  
K. Paipitak ◽  
J. Rattanarak ◽  
D. Pakdeeyingyong ◽  
W. Techitdheera ◽  
S. Porntheeraphat ◽  
...  

The paper describes the results obtained on the enhanced electrochromic performance of Tungsten oxide (WO3) thin films assisted by electrospun PVA nanofibers. WO3 was fabricated by spin coating technique with tungsten powder as starting precursor. The effect of electrospun-PVA nanofibers layer on structural, chemical composition, surface morphology and electrochromic properties of the films were characterized by X-ray diffractometer (XRD), X-ray photo-emission spectroscopy (XPS), scanning electron microscope (SEM) and UV-VIS spectrophotometer. The XRD analysis suggested that the crystalline of WO3 can be identified as a monoclinic WO3 structure. XPS investigations also confirmed the existence of characteristic peaks of W. The significant enhancement of electrochromic properties of the films is achieved by additive electrospun-PVA nanofiber layer.


2015 ◽  
Vol 9 (3) ◽  
pp. 151-156 ◽  
Author(s):  
Jelena Vukmirovic ◽  
Djordjije Tripkovic ◽  
Branimir Bajac ◽  
Sanja Kojic ◽  
Goran Stojanovic ◽  
...  

In this paper, barium titanate films were prepared by different deposition techniques (spin coating, office Epson inkjet printer and commercial Dimatix inkjet printer). As inkjet technique requires special rheological properties of inks the first part of the study deals with the preparation of inks, whereas the second part examines and compares structural characteristics of the deposited films. Inks were synthesized by sol-gel method and parameters such as viscosity, particle size and surface tension were measured. Deposited films were examined by optical and scanning electron microscopy, XRD analysis and Raman spectroscopy. The findings consider advantages and disadvantages of the particular deposition techniques.


2012 ◽  
Vol 581-582 ◽  
pp. 514-518
Author(s):  
Hong Zhu ◽  
Zhi Jun Guo ◽  
Wein Duo Yang ◽  
Wein Feng Chang

This study investigated the structure, microstructure and optical properties of the highly-oriented lead barium titanate (Pb1-xBaxTiO3, PBT) thin films prepared on MgO (100) substrate by a nonaqueous sol-gel process. The film precursor was synthesized by the modified sol-gel processing from lead acetate, barium acetate, and titanium isopropoxide, acetylacetone as chelating agent, and ethylene glycol as solvent. This stable precursor was formed by acetylacetone chelating with titanium isopropoxide and then mixing the solution of the acetates. The spin-coating technique was used to deposit the PBT films on MgO (100) substrate with different barium contents and various spin-coating numbers, respectively. X-ray diffraction was employed to study the crystal structure of the thin film and field emission scanning electron microscopy was used to characterize the microstructure of the films. Optical properties of the thin films were investigated by Ultraviolet-visible spectrophotometer. All films exhibited a (100) preferred orientation, especially the PB0.5T (3-coating layers) thin film. In the optical properties, the adsorption wavelength shifted to the ultraviolet region with increasing barium.


2021 ◽  
Vol 18 (2) ◽  
pp. 147-160
Author(s):  
Rohanieza Abdul Rahman ◽  
◽  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Rosalena Irma Alip ◽  
...  

This paper presents the investigation of the thickness of the ZnO thin films by varying the number of deposition layers during the spin coating deposition process. ZnO thin films were deposited with a different number of layers (ranging from 1, 3, and 5), and the main purpose of this study is to explore the effect of the thickness on the properties of ZnO thin films. The deposited thin films were characterised using field emission scanning electron microscope, surface profilometer, and X-ray diffraction. From the characterisation results, the morphology of the ZnO thin films changed significantly with the number of layers and their thickness value. As expected, the thickness increased as the number of layers increased. The crystalline quality of the deposited film improved as the thickness increased. A change in crystallographic orientation was also observed in which the thicker, thin films showed crystal growth in the (102) direction, whereas the thinner one was in the (101) direction. A slight increase in crystallite size for dominant orientation also was observed with the increase of film thickness.


2019 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
KOMARAIAH DURGAM ◽  
RADHA EPPA ◽  
REDDY M. V. RAMANA ◽  
KUMAR J. SIVA ◽  
R. SAYANNA ◽  
...  

Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.


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