Enhancement in visible luminescence from nanocomposite ZnO-SiOx thin films due to annealing

2014 ◽  
Vol 07 (02) ◽  
pp. 1450007 ◽  
Author(s):  
V. V. Siva Kumar ◽  
D. Kanjilal
Keyword(s):  
Thin Films ◽  
Size Distribution ◽  
High Vacuum ◽  
Wide Band ◽  
Silica Matrix ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Zno Nanocrystals ◽  
Transmission Electron ◽  
Pl Emission

The annealing induced enhancement in visible photoluminescence (PL) from nanocomposite (nc) ZnO – SiO x thin films was investigated. Nc ZnO – SiO x thin films consisting of ZnO nanocrystals in silica matrix were grown by depositing the films using radio frequency (rf) reactive co-sputtering and post-annealing them at temperatures of 350°C and 500°C in high vacuum and air. These films were characterized by Fourier transform infrared (FTIR), (PL) spectroscopy and UV–Vis spectrophotometry measurements. Thin films were also deposited on transmission electron microscopy (TEM) grids in almost identical conditions. The TEM measurement of the thin film deposited on TEM grid shows the formation of ZnO nanocrystals with a size distribution from 3.0 nm to 6.8 nm (+/-0.2 nm) in silica matrix. The UV–Vis spectra of the films show absorption features of ZnO and Zn 2 SiO 4 phases in the films. The visible PL emission intensity and peak width increased in the annealed films. The results suggest increase in the number and size distribution of the ZnO nanocrystals in silica matrix due to the annealing resulting in increase in visible PL emission. The results of vacuum annealed films indicate that these films can be useful in the development of wide band visible light emitting devices using this material.

Blue like Diamond Light Emitting Devices to be Massproduced

1989 ◽  
Vol 162 ◽  
Author(s):  
M. Kadono ◽  
S. Hayashi ◽  
N. Hirose ◽  
K. Itoh ◽  
T. Inushima ◽  
...  
Keyword(s):  
Thin Films ◽  
Electronic Device ◽  
Electronic Devices ◽  
Chemical Properties ◽  
Wide Band ◽  
Wide Band Gap ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Device Applications ◽  
Diamond Thin Films

Recently, there has been considerable interest in electronic device applications of diamond thin films. The chemical properties of diamond is stable. So diamond thin films become very useful if they are used for electronic devices. We consider diamond thin films as blue like emitting devices because diamond has a wide band gap(about 5.5eV). Some light emitting devices have been known [1]. First of all we have been trying to deposit diamond thin films on the large areas. If they deposit on the large areas, light emitting devices may be massproduced.

scholarly journals Structural and optical properties of Zn-implanted silica: effect of fluence and annealing

2020 ◽  
Vol 64 (3) ◽  
pp. 273-281
Author(s):  
M. A. Makhavikou ◽  
O. V. Milchanin ◽  
I. N. Parkhomenko ◽  
F. F. Komarov ◽  
L. A. Vlasukova ◽  
...  
Keyword(s):  
Phase Space ◽  
Silica Film ◽  
Silica Matrix ◽  
Silica Films ◽  
Light Emitting ◽  
Space Group ◽  
Zno Nanocrystals ◽  
Transmission Electron ◽  
Large Clusters ◽  
Small Clusters

The phase-structural composition of a silica film grown on Si substrate implanted with Zn ions at room temperature with different fluences has been studied using transmission electron microscopy and electron diffraction. The small clusters (1–2 nm) and the large clusters (5–7 nm) have been formed in as-implanted silica films with the Zn concentration of 6–7 at % and 16–18 at %, respectively. Furnace annealing at 750 °С for two hours results both in the formation of the orthorhombic Zn2SiO4 phase (space group R-3) in the case of low fluence (5 · 1016 cm–2) and in the formation of the cubic ZnO phase (space group F-43m) in the case of high fluence (1 · 1017 cm–2). It has been shown that impurity loss during implantation and subsequent annealing increase with fluence of implanted ions. The fraction of Zn atoms in clusters has been estimated to be 15 % and 18 % for fluences (5 · 1016 cm–2) and (1 · 1017 cm–2), respectively. It has been shown that residual Zn impurities dissolved in silica matrix noticeably suppress the light-emitting properties of silica with embedded Zn2SiO4 and ZnO nanocrystals.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Light emitting devices from organic charge transfer adduct thin films

1999 ◽  
Vol 40 (6) ◽  
pp. 285-293 ◽  
Author(s):  
Poopathy Kathirgamanathan ◽  
Vijendra Kandappu ◽  
Susumu Hara ◽  
Kanagarajah Chandrakumar ◽  
S.Leo Marianesan ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Transfer ◽  
Light Emitting ◽  
Light Emitting Devices

ZnO Nanocrystal Thin Films for Quantum-Dot Light-Emitting Devices

2020 ◽  
Vol 3 (8) ◽  
pp. 7535-7542
Author(s):  
Wooje Han ◽  
Seongkeun Oh ◽  
Chan Lee ◽  
Jiwan Kim ◽  
Hyung-Ho Park
Keyword(s):  
Thin Films ◽  
Quantum Dot ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Zno Nanocrystal

Structure and Magnetic Properties of Fe-N Thin Films Grown by ECR Deposition

1999 ◽  
Vol 562 ◽  
Author(s):  
Š émeth ◽  
H. Akinaga ◽  
H. Boeve ◽  
H. Bender ◽  
J. de Boeck ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Nitrogen Concentration ◽  
High Vacuum ◽  
Plasma Source ◽  
Columnar Structure ◽  
Ultra High Vacuum ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTThe growth of FexNy thin films on GaAs, In0.2Ga0.8As, and SiO2/Si substrates using an ultra high-vacuum (UHV) deposition chamber equipped with electron cyclotron resonance (ECR) microwave plasma source is presented. The structural properties of the deposited films have been measured using various techniques as x-ray diffraction (XRD), Auger electron spectroscopy (AES), and transmission electron microscopy (TEM). The results of XRD measurements show that the films consist of a combination of α-Fe, α'-Fe, y-Fe4N, and α”- Fe16N2 phases. The depth profiles, calculated from the Auger peak intensities, show a uniform nitrogen concentration through the films. The TEM reveals a columnar structure of these films. The properties of the different Fe-N layers have been exploited in the fabrication of Fe(N) / FexNy / Fe trilayer structures, where Fe(N) means a slightly nitrogen doped Fe film. The magneto-transport properties of this trilayer structure grown on In0.2Ga0.8As substrates are presented.

Structrual Characterization and Raman Scattering of Epitaxial Aluminum Nitride Thin Films on Si(111)

1992 ◽  
Vol 242 ◽  
Author(s):  
W. J. Meng ◽  
T. A. Perry ◽  
J. Heremans ◽  
Y. T. Cheng
Keyword(s):  
Thin Films ◽  
Aluminum Nitride ◽  
Raman Scattering ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reactive Sputter Deposition ◽  
Transmission Electron ◽  
Substrate Temperatures

ABSTRACTThin films of aluminum nitride were grown epitaxially on Si(111) by ultra-high-vacuum dc magnetron reactive sputter deposition. Epitaxy was achieved at substrate temperatures of 600° C or above. We report results of film characterization by x-ray diffraction, transmission electron microscopy, and Raman scattering.

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