Photoluminescence Variation With Temperature in ZnO:Ag Nanorods obtained by Ultrasonic Spray Pyrolysis

2013 ◽  
Vol 1617 ◽  
pp. 113-117
Author(s):  
E. Velázquez Lozada ◽  
S. Mera Luna ◽  
L. Castañeda
Keyword(s):  
Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis ◽  
Second Order ◽  
Band Edge ◽  
Near Band Edge ◽  
Pl Spectra ◽  
Ultrasonic Spray ◽  
Order Diffraction ◽  
Temperature Dependences ◽  
Ir Emission

ABSTRACTThe photoluminescence, its temperature dependences, as well as structural characteristics obtained by the method of Scanning electronic microscopy (SEM) have been studied in ZnO:Ag nanorods prepared by the ultrasonic spray pyrolysis (USP). PL spectra of ZnO:Ag NRs in the temperature range from 10 K to 300 K are investigated. Three types of PL bands have been revealed: i) the near-band-edge (NBE) emission, ii) defect related emission and iii) IR emission. It is shown that IR emission corresponds to the second-order diffraction of near-band-edge (NBE) emission bands. The study of NBE PL temperature dependences reveals that the acceptor bound exciton (ABE) and its second-order diffraction peak disappeared at the temperature higher than 200 K. The attenuation of the ABE peak intensity is ascribed to the thermal dissociation of ABE with appearing a free exciton (FE). The PL bands, related to the LO phonon replica of FE and its second-order diffraction, dominate in the PL spectra at room temperature that testify on the high quality of ZnO:Ag films prepared by the USP technology.

Emission Diversity of ZnO Nanocrystals with Different Growth Temperatures

2014 ◽  
Vol 1675 ◽  
pp. 45-51
Author(s):  
E. Velázquez Lozada ◽  
T. Torchynska ◽  
G. Camacho González
Keyword(s):  
Free Exciton ◽  
Ultrasonic Spray Pyrolysis ◽  
Second Order ◽  
Zno Films ◽  
Near Band Edge ◽  
Phonon Replica ◽  
Ultrasonic Spray ◽  
Zno Nanocrystals ◽  
Order Diffraction ◽  
Different Temperatures

ABSTRACTScanning electronic microscopy (SEM), X ray diffraction (XRD) and photoluminescence (PL) have been applied to the study of structural and optical properties of ZnO nanocrystals prepared by the ultrasonic spray pyrolysis (USP) at different temperatures. The variation of temperatures and times at the growth of ZnO films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO nanocrystals (NCs), as well as to vary their photoluminescence spectra. The study has revealed three types of PL bands in ZnO NCs: defect related emission, the near-band-edge (NBE) PL, related to the LO phonon replica of free exciton (FE) recombination, and its second-order diffraction peaks. The PL bands, related to the LO phonon replica of FE, and its second-order diffraction in the room temperature Pl spectrum testify on the high quality of ZnO films prepared by the USP technology.

Study on aluminum concentration on optical and electrical properties of AZO thin films fabricated by ultrasonic spray pyrolysis

2019 ◽  
Vol 33 (22) ◽  
pp. 1950246
Author(s):  
Weiguang Yang ◽  
Miao He ◽  
Liu Yang ◽  
Ziliang Zhou ◽  
Xiaoying Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Spray Pyrolysis ◽  
Quartz Substrate ◽  
Visible Region ◽  
Ultrasonic Spray Pyrolysis ◽  
Aluminum Concentration ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Ultrasonic Spray

In this work, transparent and conductive Al-doped ZnO (AZO) nanofilms were prepared on quartz substrate by ultrasonic spray pyrolysis (USP) method. The effects of Al/Zn atomic ratios on the micro-structural, morphological, optical photoluminescence and electrical properties of AZO thin films were effectively investigated. All the prepared samples showed hexagonal wurtzite structure. The scanning electron microscopy (SEM) showed that the surface morphology of all samples changed with the substrate temperature. The average transmittance of all AZO samples was higher than 85% in the visible region. The photoluminescence (PL) spectrum of the samples showed that the near band edge emission in PL spectra shifted to shorter wavelengths with increasing Al-doped concentration. The lowest sheet resistance was obtained for the samples prepared with 4% at. Al-doped value. The electrical conductivity of AZO films was improved by Al doping, which allowed their use as optoelectronic materials.

Temperature-dependent shifts of near band-edge emission and their second-order diffraction for ZnO nanorods

2012 ◽  
Vol 34 (11) ◽  
pp. 1917-1920 ◽  
Author(s):  
Jianguo Lv ◽  
Changlong Liu ◽  
Wanbing Gong ◽  
Zhenfa Zi ◽  
Xiaoshuang Chen ◽  
...  
Keyword(s):  
Zno Nanorods ◽  
Second Order ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Temperature Dependent ◽  
Edge Emission ◽  
Order Diffraction

Zinc Oxide Thin Films with Reduced Native Compensative Defects Grown by Ultrasonic Spray Pyrolysis at Atmosphere

2007 ◽  
Vol 336-338 ◽  
pp. 589-592
Author(s):  
Jian Ling Zhao ◽  
Xiao Min Li ◽  
Ji Ming Bian ◽  
Wei Dong Yu ◽  
C.Y. Zhang
Keyword(s):  
Spray Pyrolysis ◽  
Deep Level ◽  
Hole Concentration ◽  
Ultrasonic Spray Pyrolysis ◽  
Zno Films ◽  
Near Band Edge ◽  
Dense Microstructure ◽  
Ultrasonic Spray ◽  
High Hole Concentration ◽  
P Type

ZnO films were deposited on Si (100) substrate by ultrasonic spray pyrolysis at atmosphere. The film grown at optimum conditions is well crystallized with uniform, smooth and dense microstructure. Photoluminescence measurement shows a strong near band edge UV emission at 379nm and an almost undetectable deep-level emission band centered at 502nm. The resistivity of ZnO film is reduced by an order after N-In codoping, which produces p-type conduction with high hole concentration and hall mobility.

Fireworks: How to Simulate the Manufacture and Operation in the Atmosphere with the Substitution of Ultrasonic Spray Pyrolysis

2018 ◽  
Vol 15 (2) ◽  
pp. 147-156
Author(s):  
Rebeka Rudolf ◽  
Urban Ferčec ◽  
Mohammed Shariq
Keyword(s):  
Spray Pyrolysis ◽  
Final Section ◽  
Web Of Science ◽  
Raw Materials ◽  
Ultrasonic Spray Pyrolysis ◽  
Physiochemical Properties ◽  
Physical Size ◽  
Respiratory Problems ◽  
Ultrasonic Spray ◽  
Temperature Ranges

Background: This review provides a closer look at recent work in the field of fireworks manufacture, which could see the replacement of micron-sized particles with their nano-scaled counterparts. Moreover, we also discuss micron-sized particles as well as nanoparticles (NPs) from K, Fe, Al, Ti, Ba, etc., that are produced in the atmosphere as a result of these fireworks. One of the possible technological substitutes for fireworks is presented in detail, i.e., the use of ultrasonic spray pyrolysis (USP) technology. Method: We searched Google, Web of Science and PubMed for a literature survey of fireworks and their products: firecrackers, micron-sized and nanoparticles. Moreover, we used some of our own knowledge and experimental data to strengthen the possibility of simulating the synthesis of firework products on the laboratory scale. Results: The use of nano reactants and oxidisers has seen a substantial increase in the sound efficiency and a decrease in the amount of chemicals used, making fireworks more eco-friendly. The application of Al- and Ti-based nano flash powder in the size range from 35 nm to 50 μm resulted in a significant improvement in the ignition properties of the fireworks. Under changing aerodynamic conditions, it is difficult to collect them as samples for real-time monitoring, needed for their characterization or the testing of their harmfulness under laboratory conditions. As a result, NPs below 100 nm in the surroundings could be easily inhaled into the lungs and cause more pulmonary and respiratory problems than micron-sized particles. USP produces nanoparticles in the laboratory that could replace the conventional micron-sized firecracker raw materials, or nanoparticles that are similar to those formed by fireworks. It will also help to identify the physiochemical properties of the airborne particulates in order to understand and evaluate their impact. </P><P> This review could be valuable for a controlled economic synthesis through USP, and in the use of nanopowders in pyrotechnology that could reduce pollution to a great extent, thus contributing to the growth and good practise of the fireworks industry. With respect to the USP synthesis, we have also discussed in detail the physical (size, shape) and chemical (composition) characteristics of Al2O3 and TiO2 NPs from different precursors and their temperature ranges. An in-depth explanation for a comparative analysis for the formation mechanism of nanoparticles through both fireworks and USP is presented in the final section. We can produce nanoparticles in the laboratory with ultrasonic spray pyrolysis that have similar properties to those produced from fireworks and can then be used for further testing.

scholarly journals Strong texture tuning along different crystalline directions in glass-supported CeO2 thin films by ultrasonic spray pyrolysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Inti Zumeta-Dubé ◽  
José Manuel García Rangel ◽  
Jorge Roque ◽  
Issis Claudette Romero-Ibarra ◽  
Mario Fidel García Sánchez
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Morphological Characteristics ◽  
Ultrasonic Spray Pyrolysis ◽  
Cost Effective ◽  
Growth Direction ◽  
Large Area ◽  
Smart Windows ◽  
Ultrasonic Spray

AbstractThe strong facet-dependent performance of glass-supported CeO2 thin films in different applications (catalysis, smart windows, etc.) has been the target of diverse fundamental and technological approaches. However, the design of accurate, cost-effective and scalable methods with the potential for large-area coverage that produce highly textured glass-supported CeO2 thin films remains a technological challenge. In the present work, it is demonstrated that under proper tuning conditions, the ultrasonic spray pyrolysis technique enables one to obtain glass-supported polycrystalline CeO2 films with noticeable texture along both the (100) and (111) directions, as well as with randomly oriented crystallites (no texture). The influence of flow rates, solution molarity, and substrate temperature on the texture and morphological characteristics, as well as optical absorption and Raman response of the deposited films, is evaluated. The obtained results are discussed on the basis of the combined dependence of the CeO2-exposed surfaces on the thermodynamic stability of the corresponding facets and the reaction kinetics, which modulate the crystallite growth direction.

Transparent MIS capacitors on plastic substrates fabricated by high-frequency ultrasonic spray pyrolysis

2021 ◽  
Vol 44 (2) ◽  
Author(s):  
Ovier Obregon ◽  
José A Luna-Lopez ◽  
Pedro Rosales ◽  
Mario Moreno ◽  
Abdu Orduña-Diaz ◽  
...  
Keyword(s):  
Spray Pyrolysis ◽  
High Frequency ◽  
Ultrasonic Spray Pyrolysis ◽  
Plastic Substrates ◽  
Ultrasonic Spray ◽  
Mis Capacitors
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