Influence of Post Growth Annealing on the Optical Properties of Gallium Nitride Films Grown by Pulsed Laser Deposition

2012 ◽  
Vol 1432 ◽  
Author(s):  
M. Baseer Haider ◽  
M. F. Al-Kuhaili ◽  
S. M. A. Durrani ◽  
Imran Bakhtiari

Abstract:Gallium nitride thin films were grown by pulsed laser deposition. Subsequently, post-growth annealing of the samples was performed at 400, and 600 oC in the nitrogen atmosphere. Surface morphology of the as-grown and annealed samples was performed by atomic force microscopy, surface roughness of the films improved after annealing. Chemical analysis of the samples was performed using x-ray photon spectroscopy, stoichiometric Gallium nitride thin films were obtained for the samples annealed at 600 oC. Optical measurements of the samples were performed to investigate the effect of annealing on the band gap and optical constants the films.

2010 ◽  
Vol 150-151 ◽  
pp. 908-911 ◽  
Author(s):  
Wei Rao ◽  
Jun Yu

(La0.7Sr0.3)MnO3 (LSMO) thin films were prepared on Si (100) substrate by pulsed laser deposition (PLD). Both structure and surface morphology of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The results indicate that the films grown on Si (100) substrates have a single pseudo cubic perovskite phase structure with a high (100) orientation. The XPS results show that La, Sr and Mn exist mainly in the forms of perovskite structure and a SrO layer was found on outermost surface.


2011 ◽  
Vol 284-286 ◽  
pp. 2191-2197 ◽  
Author(s):  
Hui Fang Xiong ◽  
Tie Dong Cheng ◽  
X.G. Tang ◽  
Jian Chen ◽  
Qiu Xiang Liu

(La0.7Sr0.3)MnO3 (LSMO) thin films were grown on Si (100) substrate by using pulsed laser deposition (PLD) process. Both structure and surface morphology of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. From XRD, the results indicate that the films grown on Si (100) substrates have a single pseudocubic perovskite phase structure with a high (100) orientation. The XPS results show that La, Sr and Mn exist mainly in the forms of perovskite structure and a SrO layer was found on outermost surface. The films resistivity emeasured under room temperature is 6.4´10-4 W×cm.


Author(s):  
Sudheer Neralla ◽  
Sergey Yarmolenko ◽  
Dhananjay Kumar ◽  
Devdas Pai ◽  
Jag Sankar

Alumina is a widely used ceramic material due to its high hardness, wear resistance and dielectric properties. The study of phase transformation and its correlation to the mechanical properties of alumina is essential. In this study, interfacial adhesion properties of alumina thin films are studied using cross-sectional nanoindentation (CSN) technique. Alumina thin films are deposited at 200 and 700 °C, on Si (100) substrates with a weak Silica interface, using pulsed laser deposition (PLD) process. Effect of annealing on the surface morphology of the thin films is studied using atomic force microscopy. Xray diffraction studies revealed that alumina thin films are amorphous in nature at 200 °C and polycrystalline with predominant gamma alumina phase at 700 °C.


2000 ◽  
Vol 658 ◽  
Author(s):  
Trong-Duc Doan ◽  
Cobey Abramowski ◽  
Paul A. Salvador

ABSTRACTThin films of NdNiO3 were grown using pulsed laser deposition on single crystal substrates of [100]-oriented LaAlO3 and SrTiO3. X-ray diffraction and reflectivity, scanning electron microscopy, and atomic force microscopy were used to characterize the chemical, morphological and structural traits of the thin films. Single-phase epitaxial films are grown on LaAlO3 and SrTiO3 at 625°C in an oxygen pressure of 200 mTorr. At higher temperatures, the films partially decompose to Nd2NiO4 and NiO. The films are epitaxial with the (101) planes (orthorhombic Pnma notation) parallel to the substrate surface. Four in-plane orientational variants exist that correspond to the four 90° degenerate orientations of the film's [010] with respect to the in-plane substrate directions. Films are observed to be strained in accordance with the structural mismatch to the underlying substrate, and this leads, in the thinnest films on LaAlO3, to an apparent monoclinic distortion to the unit cell.


2018 ◽  
Vol 9 ◽  
pp. 686-692 ◽  
Author(s):  
Daiki Katsube ◽  
Hayato Yamashita ◽  
Satoshi Abo ◽  
Masayuki Abe

We have designed and developed a combined system of pulsed laser deposition (PLD) and non-contact atomic force microscopy (NC-AFM) for observations of insulator metal oxide surfaces. With this system, the long-period iterations of sputtering and annealing used in conventional methods for preparing a metal oxide film surface are not required. The performance of the combined system is demonstrated for the preparation and high-resolution NC-AFM imaging of atomically flat thin films of anatase TiO2(001) and LaAlO3(100).


RSC Advances ◽  
2016 ◽  
Vol 6 (116) ◽  
pp. 115039-115045 ◽  
Author(s):  
Qing Liu ◽  
Jieling Zhang ◽  
Ling Wei ◽  
Weifeng Zhang

Bi(1+x)FeO3 thin films with different Bi contents (x = 0%, 5%, and 10%) were grown on (001) SrTiO3 substrates with La0.65Sr0.35MnO3 (LSMO) buffered layers via pulsed laser deposition.


2012 ◽  
Vol 30 (4) ◽  
pp. 559-567 ◽  
Author(s):  
A.T.T. Mostako ◽  
Alika Khare

AbstractMirror like Molybdenum thin films on SS substrate in vacuum (10−3Pa) and in Helium environment has been achieved by Pulsed Laser Deposition (PLD) Technique. The PLD thin films of Molybdenum have been characterized by using X-ray Diffraction (XRD) pattern, Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM) and Energy Dispersive X-ray (EDX). The specular reflectivity was recorded with Fourier Transform Infra-Red spectrometer and UV-Visible spectrometer. The optical quality of the thin films was tested via interferometric technique. At the optimum deposition parameters, the crystal orientation was in Mo(110) phase. The FIR-UV-Visible reflectivity of the mirror was found to be closed to that of the polished bulk Molybdenum and Stainless Substrate (SS) substrate.


2014 ◽  
Vol 32 (4) ◽  
pp. 541-546 ◽  
Author(s):  
P. Nagaraju ◽  
Y. Vijayakumar ◽  
D. Phase ◽  
V. Reddy ◽  
M. Ramana Reddy

AbstractMicrostructural properties of Ce1-x GdxO2-δ (x = 0 to 0.3) thin films prepared by pulsed laser deposition technique were studied. The thin films were deposited on Si(100) substrate at a substrate temperature of 973 K at the oxygen partial pressure of 0.2 Pa using KrF excimer laser with energy of 220 mJ. The prepared thin films were characterized by X-ray diffraction, Raman spectroscopy and atomic force microscopy. X-ray diffraction analysis confirmed the polycrystalline nature of the thin films. Crystallite size, strain and dislocation density were calculated. The Raman studies revealed the formation of Ce-O with the systematic variation of peak intensity and full width half maxima depending on concentration of gadolinium dopant. The thickness of the films was estimated using Talystep profiler. The surface roughness was estiamted based on AFM.


2008 ◽  
Vol 368-372 ◽  
pp. 322-325
Author(s):  
G.X. Liu ◽  
F.K. Shan ◽  
Byoung Chul Shin ◽  
Won Jae Lee

Pulsed laser deposition (PLD) technique is a very powerful method for fabricating various oxide thin films due to its native merits. In this study, gallium and nitrogen co-doped ZnO thin films (0.1 at.%) were deposited at different temperatures (100-600°C) on sapphire (001) substrates by using PLD. X-ray diffractometer, atomic force microscope, spectrophotometer, and spectrometer were used to characterize the structural, the morphological and the optical properties of the thin films. Hall measurements were also carried out to identify the electrical properties of the thin films.


Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 958
Author(s):  
Yeong-Maw Hwang ◽  
Cheng-Tang Pan ◽  
Bo-Syun Chen ◽  
Phuoc Huu Le ◽  
Ngo Ngoc Uyen ◽  
...  

In the present study, the structural, morphological, compositional, nanomechanical, and surface wetting properties of Bi2Se3 thin films prepared using a stoichiometric Bi2Se3 target and a Se-rich Bi2Se5 target are investigated. The Bi2Se3 films were grown on InP(111) substrates by using pulsed laser deposition. X-ray diffraction results revealed that all the as-grown thin films exhibited were highly c-axis-oriented Bi2Se3 phase with slight shift in diffraction angles, presumably due to slight stoichiometry changes. The energy dispersive X-ray spectroscopy analyses indicated that the Se-rich target gives rise to a nearly stoichiometric Bi2Se3 films, while the stoichiometric target only resulted in Se-deficient and Bi-rich films. Atomic force microscopy images showed that the films’ surfaces mainly consist of triangular pyramids with step-and-terrace structures with average roughness, Ra, being ~2.41 nm and ~1.65 nm for films grown with Bi2Se3 and Bi2Se5 targets, respectively. The hardness (Young’s modulus) of the Bi2Se3 thin films grown from the Bi2Se3 and Bi2Se5 targets were 5.4 GPa (110.2 GPa) and 10.3 GPa (186.5 GPa), respectively. The contact angle measurements of water droplets gave the results that the contact angle (surface energy) of the Bi2Se3 films obtained from the Bi2Se3 and Bi2Se5 targets were 80° (21.4 mJ/m2) and 110° (11.9 mJ/m2), respectively.


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