Effect of Ethylenediamine Tetraacetic Acid in Electrochemical Deposition of Zinc Selenide

2012 ◽  
Vol 501 ◽  
pp. 231-235
Author(s):  
Sook Mey Ng ◽  
Zulkarnain Zainal ◽  
Mat Yunus Wan Mahmood
Keyword(s):  
Zinc Selenide ◽  
Surface Defects ◽  
Low Cost ◽  
Quantum Confinement Effect ◽  
Green Light ◽  
Photoluminescence Intensity ◽  
Tetraacetic Acid ◽  
Photoelectrochemical Performance ◽  
Light Emitting ◽  
Ethylenediamine Tetraacetic Acid

Zinc selenide based materials are suitable for fabrication of light emitting diodes operating in the blue-green light. In fabrication of zinc selenide films, electrodeposition method appears to be the simplest and low-cost technique. In this work, the application of ethylenediamine tetraacetic acid (EDTA) in electrodeposition of zinc selenide was investigated to evaluate its effect on the optical and electronic properties of the films. It was found that the presence of EDTA stabilized the cathodic over potential during deposition. The zinc selenide deposits consist of small grain size deposits which contribute to enhance the photoelectrochemical performance. Besides that, the zinc selenide films produced in the presence of EDTA also shows high photoluminescence intensity due to minimized surface defects on the glass substrate. The film shows photoluminescence peak at the blue region of wavelength due to its quantum confinement effect. The optical property of zinc selenide film was measured using ultraviolet-visible spectrophotometer. The band gap of zinc selenide is 2.65 eV with direct transition.

scholarly journals Fricke Dosimetry as a Tool to Quality Control of Photodynamic Therapy

2019 ◽  
Vol 7 (3) ◽  
Author(s):  
SUZANA OLIVEIRA SANTOS ◽  
Vivianne L. B. Souza
Keyword(s):  
Quality Control ◽  
Photodynamic Therapy ◽  
Low Cost ◽  
Red Light ◽  
Green Light ◽  
Yellow Light ◽  
Light Emitting ◽  
Low Toxicity ◽  
Cellular Necrosis ◽  
Photosensitizing Agent

Photodynamic therapy (PDT) consists of the association of a photosensitizing agent with a light source in order to cause cellular necrosis. Methylene blue, toluidine blue and malachite green are photosensitizers derived from dyes that are widely accepted in medicine, as they have low toxicity and are low cost. PDT is an alternative treatment for cancer, with significant advantages over procedures such as surgery/chemotherapy. Our laboratory has studied the Fricke solution doped with photosensitizers in an approach to obtain a quality control for PDT. The Fricke solution was prepared with ammoniacal ferrous sulfate, sodium chloride and sulfuric acid in water. The solutions modified with photosensitizers were prepared by adding 0.1 g/100 mL of the dyes. A volume of 2.6 ml of the Fricke solution modified with photosensitizers were transferred to test tubes and irradiated. The irradiated solutions had their optical densities measured in a spectrophotometer. The samples were irradiated with LED (Light Emitting Diodes) in acrylic phantoms. The FATA samples irradiated with LED showed the sensitivity of the dosimeters to red, blue, green and yellow light. A calibration curve with correlation coefficient of 0.9884 for the red light was obtained; 0.9752 for blue light; 0.9644 for the green light and 0.9768 for the yellow light. The fact that a sensitivity of the dosimeters to the LED has been occurred indicates that the PDT could be realized with LED, with lower costs than with laser. This work suggested that FATA dosimeters can be used for quality control of PDT.

scholarly journals CMOS-Compatible and Low-Cost Thin Film MACE Approach for Light-Emitting Si NWs Fabrication

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 966
Author(s):  
Antonio Alessio Leonardi ◽  
Maria José Lo Faro ◽  
Alessia Irrera
Keyword(s):  
Silicon Nanowires ◽  
Low Cost ◽  
Quantum Confinement Effect ◽  
High Surface ◽  
Volume Ratio ◽  
Cmos Technology ◽  
High Density ◽  
Synthesis Methods ◽  
Light Emitting ◽  
Strong Control

Silicon nanowires (Si NWs) are emerging as an innovative building block in several fields, such as microelectronics, energetics, photonics, and sensing. The interest in Si NWs is related to the high surface to volume ratio and the simpler coupling with the industrial flat architecture. In particular, Si NWs emerge as a very promising material to couple the light to silicon. However, with the standard synthesis methods, the realization of quantum-confined Si NWs is very complex and often requires expensive equipment. Metal-Assisted Chemical Etching (MACE) is gaining more and more attention as a novel approach able to guarantee high-quality Si NWs and high density with a cost-effective approach. Our group has recently modified the traditional MACE approach through the use of thin metal films, obtaining a strong control on the optical and structural properties of the Si NWs as a function of the etching process. This method is Complementary Metal-Oxide-Semiconductors (CMOS)-technology compatible, low-cost, and permits us to obtain a high density, and room temperature light-emitting Si NWs due to the quantum confinement effect. A strong control on the Si NWs characteristics may pave the way to a real industrial transfer of this fabrication methodology for both microelectronics and optoelectronics applications.

scholarly journals Illuminating gillnets to save seabirds and the potential for multi-taxa bycatch mitigation

2018 ◽  
Vol 5 (7) ◽  
pp. 180254 ◽  
Author(s):  
Jeffrey C. Mangel ◽  
John Wang ◽  
Joanna Alfaro-Shigueto ◽  
Sergio Pingo ◽  
Astrid Jimenez ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Low Cost ◽  
Green Light ◽  
Marine Species ◽  
Sea Turtle ◽  
Catch Per Unit Effort ◽  
Light Emitting ◽  
Incidental Capture ◽  
Unit Effort ◽  
Mitigation Technique

Bycatch in net fisheries is recognized as a major source of mortality for many marine species, including seabirds. Few mitigation solutions, however, have been identified. We assessed the effectiveness of illuminating fishing nets with green light emitting diodes (LEDs) to reduce the incidental capture of seabirds. Experiments were conducted in the demersal, set gillnet fishery of Constante, Peru and compared 114 pairs of control and illuminated nets. We observed captures of a total of 45 guanay cormorants ( Phalacrocorax bougainvillii ), with 39 caught in control nets and six caught in illuminated nets. Seabird bycatch in terms of catch-per-unit-effort was significantly ( p  < 0.05) higher in control nets than in illuminated nets, representing an 85.1% decline in the cormorant bycatch rate. This study, showing that net illumination reduces seabird bycatch and previous studies showing reductions in sea turtle bycatch without reducing target catch, indicates that net illumination can be an effective multi-taxa bycatch mitigation technique. This finding has broad implications for bycatch mitigation in net fisheries given LED technology's relatively low cost, the global ubiquity of net fisheries and the current paucity of bycatch mitigation solutions.

The Characteristics of High-Temperature Synthesized YAG:Ce Nano-Phosphors

2011 ◽  
Vol 145 ◽  
pp. 194-198
Author(s):  
Hao Ying Lu ◽  
Hua Wei Yang
Keyword(s):  
High Temperature ◽  
Low Cost ◽  
Average Particle Size ◽  
Synthesis Temperature ◽  
Average Particle ◽  
Photoluminescence Intensity ◽  
Excitation Spectra ◽  
Light Emitting ◽  
Xrd Diffraction ◽  
Co Precipitation

In the last decade, nanosized phosphors had attracted a lot of interest, no matter in light emitting layers or thermal remove materials. Many methods had been investigated to synthesize nanosized phosphors, but they usually need expensive cost and complicated procedures, furthermore they resulted in the difficulties in mass production. In our work, chemical co-precipitation was applied to prepare YAG:Ce precursor. Then, the mixed precipitation was heated to 900°C with air in the furnace. After 1 hour, the synthesis was completed. From TEM images, the average particle size is about 40 nm and all XRD diffraction peaks of phosphor powders were consistent to JCPDS data of YAG. Photoluminescence spectra show the nanosized YAG:Ce phosphor synthesized at 1000°C possessed the strongest photoluminescence intensity at wavelength 540 nm. From photoluminescence excitation spectra, the strongest absorption peak was observed at wavelength 460 nm in all samples. At synthesis temperature 1000°C, YAG with 0.5% Ce3+ was observed to emit the strongest yellow light. It is believed our synthesis can provide an easy and low-cost choice to synthesize YAG:Ce nanophosphors at high temperature.

scholarly journals Efficient removal of crystal violet dye using EDTA/graphene oxide functionalized corncob: a novel low cost adsorbent

RSC Advances ◽  
2019 ◽  
Vol 9 (38) ◽  
pp. 21996-22003 ◽  
Author(s):  
Huan Wang ◽  
Xin Lai ◽  
Wei Zhao ◽  
Youning Chen ◽  
Xiaoling Yang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Crystal Violet ◽  
Low Cost ◽  
Tetraacetic Acid ◽  
Efficient Removal ◽  
Immersion Method ◽  
Ethylenediamine Tetraacetic Acid ◽  
Crystal Violet Dye

In this study, crystal violet dyes were adsorbed by EDTA functionalized corncob (EDTA-corncob) and EDTA/graphene oxide functionalized corncob (EDTA-GO/corncob), which were prepared using disodium ethylenediamine tetraacetic acid and the graphene oxide immersion method.

Efficient organic manganese (II) bromide green-light-emitting diodes enabled by manipulating hole and electron transport layer

2021 ◽  
Author(s):  
Hyunsik Im ◽  
Atanu Jana ◽  
Vijaya Gopalan Sree ◽  
QIANKAI BA ◽  
Seong Chan Cho ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Green Light ◽  
Transport Layer ◽  
Lead Free ◽  
Electron Transport Layer ◽  
Flat Panel Displays ◽  
Flat Panel ◽  
Inorganic Hybrid ◽  
Light Emitting ◽  
Light Emitting Devices

Lead-free, non-toxic transition metal-based phosphorescent organic–inorganic hybrid (OIH) compounds are promising for next-generation flat-panel displays and solid-state light-emitting devices. In the present study, we fabricate highly efficient phosphorescent green-light-emitting diodes...

n-type GaN surface etched green light-emitting diode to reduce non-radiative recombination centers

2021 ◽  
Vol 118 (2) ◽  
pp. 021102
Author(s):  
Dong-Pyo Han ◽  
Ryoto Fujiki ◽  
Ryo Takahashi ◽  
Yusuke Ueshima ◽  
Shintaro Ueda ◽  
...  
Keyword(s):  
Radiative Recombination ◽  
Light Emitting Diode ◽  
Green Light ◽  
Light Emitting ◽  
Recombination Centers

scholarly journals Encapsulated Passivation of Perovskite Quantum Dot (CsPbBr3) Using a Hot-Melt Adhesive (EVA-TPR) for Enhanced Optical Stability and Efficiency

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 419
Author(s):  
Saradh Prasad ◽  
Mamduh J. Aljaafreh ◽  
Mohamad S. AlSalhi ◽  
Abeer Alshammari
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Surface Defects ◽  
Optoelectronic Devices ◽  
Ethylene Vinyl Acetate ◽  
Light Emitting ◽  
Optical Stability ◽  
Perovskite Quantum Dots ◽  
Polymer Light Emitting Diodes ◽  
Hot Melt

The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, oligomers, and dendrimers) or inorganic (ZnS, PbS) materials. In this study, we performed steady-state spectroscopic investigations to measure the photoluminescence (PL), absorption (A), transmission (T), and reflectance (R) of perovskite quantum dots (CsPbBr3) and ethylene vinyl acetate/terpene phenol (1%) (EVA-TPR (1%), or EVA) copolymer/perovskite composites in thin films with a thickness of 352 ± 5 nm. EVA is highly transparent because of its large band gap; furthermore, it is inexpensive and easy to process. However, the compatibility between PQDs and EVA should be established; therefore, a series of analyses was performed to compute parameters, such as the band gap, the coefficients of absorbance and extinction, the index of refractivity, and the dielectric constant (real and imaginary parts), from the data obtained from the above investigation. Finally, the optical conductivities of the films were studied. All these analyses showed that the EVA/PQDs were more efficient and stable both physically and optically. Hence, EVA/PQDs could become copolymer/perovskite active materials suitable for optoelectronic devices, such as solar cells and perovskite/polymer light-emitting diodes (PPLEDs).

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