Thermal Evaporation Syntheis and Luminescence Properties of SnO2 Nanocrystals using Mg as the Reducing Agent

2020 ◽  
Vol 30 (7) ◽  
pp. 338-342
Author(s):  
Ho-Jin So ◽  
◽  
Geun-Hyoung Lee
2021 ◽  
Vol 59 (4) ◽  
pp. 262-267
Author(s):  
Geun-Hyoung Lee

ZnO nano/microstructures were grown via a simple thermal evaporation process in air at atmospheric pressure. Mixtures of ZnS and carbon powders were used as the sources. The effects of growth temperature and mass ratio of carbon powder to ZnS on the morphologies and luminescence properties of the ZnO nano/microstructures were investigated in this study. When the growth temperature was 1000 <sup>o</sup>C, ZnO nanowires with a hexagonal wurtzite crystal structure started to be formed and were preferentially grown along the [0001] direction. As the temperature increased to 1200 <sup>o</sup>C, the crystal growth in the lateral direction perpendicular to the [0001] direction was enhanced, which resulted in a decreasing aspect ratio of the onedimensional ZnO nanowires. When source powders with different mass ratios of ZnS:C=2:1, 1:1 and 1:2 were used to grow ZnO nano/microstructures at 1200 <sup>o</sup>C, ZnO microrods with wurtzite crystal structure were formed in all the samples. As the mass ratio of carbon powder to ZnS increased, the aspect ratio of ZnO microrods was reduced, which suggests that the carbon powder enhanced the growth of ZnO microrods in the lateral directions. A strong ultraviolet emission band centered at 380 nm was observed in the ZnO nano/microstructures synthesized using the source powders with the mass ratios of ZnS:C=1:1 and 1:2, indicating that the ZnO nano/microstructures had a high crystalline quality.


2002 ◽  
Vol 16 (28n29) ◽  
pp. 4445-4448 ◽  
Author(s):  
KOHEI ONOZUKA ◽  
NOBUYUKI IWATA ◽  
HIROSHI YAMAMOTO

We constructed a novel vacuum system in which the cathode luminescence properties of as-prepared films can be measured in-situ. It has been observed that the Zn-Ga-O films deposited on 500°C ITO by sputtering emits light with wavelength of about 500 nm from an ultra thin Zn-rich layer formed near film surface. The luminescence induced by irradiation of electrons has also been observed for the first time in the organic bilayered TPD/Alq 3 films prepared in thermal evaporation. Its wavelength blue-shifts by about 120 nm in comparison with the electroluminescence of the same materials. The developed vacuum system is useful to characterize various thin films.


CrystEngComm ◽  
2017 ◽  
Vol 19 (30) ◽  
pp. 4321-4329 ◽  
Author(s):  
Félix del Prado ◽  
Ana Cremades ◽  
Julio Ramírez-Castellanos ◽  
David Maestre ◽  
José M. González-Calbet ◽  
...  

Li doped SnO2 microtubes were obtained by thermal evaporation using two different starting materials as precursors.


Author(s):  
J W Steeds

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.


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