scholarly journals Synthesis of ZnSe Nanocrystals for Solid-state Lighting Applications

2020 ◽  
Vol 31 (1) ◽  
Author(s):  
Tran Thi Kim Chi ◽  
Bui Thi Thu Hien ◽  
Hoang Nhu Thanh ◽  
Trinh Duc Thien ◽  
Pham Nguyen Hai
Keyword(s):  
Solid State ◽  
Large Scale ◽  
Low Cost ◽  
Solid State Lighting ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
Current Voltage ◽  
Precursor Ratio ◽  
Microscopy Characterization ◽  
Znse Nanocrystals

We report the large-scale synthesis of highly luminescent ZnSe nanocrystals (NCs) by a simple and low-cost hydrothermal method. XRD (X-ray Diffraction) and HR-TEM (High Resolution Transmission Microscopy) characterization studies confirmed the formation of as-synthesized ZnSe NCs in cubic structure. The optical property of ZnSe NCs were tunable via controlling the Zn:Se molar precursor ratio (0.5:1–1.5:1), reaction temperature (150–200 0C), and reaction time (5–30 h). The resulting ZnSe NCs with the Zn:Se precursor ratio of 1:1, hydrothermally treated at 190 0C for 20 h exhibited the highest photoluminescence quantum yield obtained by PL spectra with the 355 nm excitation. The current–voltage (I–V) characteristics of the ZnSe NCs show its promising application in the solid-state lighting.

scholarly journals Luminescence Studies of Transition Metal (Cu+ and Ag+ Ions) Activated Alkali Zinc Mixed Phosphate

2021 ◽  
Vol 04 (05) ◽  
Author(s):  
Milind Jog ◽  
Keyword(s):  
Solid State ◽  
Transition Metal ◽  
Low Cost ◽  
Solid State Lighting ◽  
Precipitation Method ◽  
Prepared Phosphor ◽  
X Ray Diffraction ◽  
Chromaticity Coordinate ◽  
Co Precipitation ◽  
Cie Chromaticity

Because of the importance of inorganic phosphates in the solid-state lighting industry, KZnPO4 doped with some transition metal dopant ions like Cu+ and Ag+ ions were prepared by low-cost co-precipitation method at room temperature followed by annealing at a high temperature around 6500C. The prepared phosphors were characterized by X-ray diffraction. In the case of a Photoluminescence study for KZnPO4 doped with Cu+, the emission was observed at 425 nm, which corresponds to the emission of Cu+ ion. In the case of Ag+ doped KZnPO4, weak emission was observed at 420 nm, which is assigned to the emission of Ag+ ions. CIE chromaticity coordinate of KZnPO4 doped with Cu+ and Ag+ ions phosphor was also evaluated via using OSRAM SYLVANIA color calculator and colour purity of concentration was nearly 95% of Cu+ and Ag+ ions. The obtained outcomes revealed that the prepared phosphor shows potential application in the field of solid-state lighting.

Low Cost Environmental Sensors Using Zinc Oxide Nanowires and Nanostructures

2012 ◽  
Vol 1439 ◽  
pp. 139-144 ◽  
Author(s):  
Nima Mohseni Kiasari ◽  
Saeid Soltanian ◽  
Bobak Gholamkhass ◽  
Peyman Servati
Keyword(s):  
Zinc Oxide ◽  
Metal Oxide ◽  
High Performance ◽  
Low Cost ◽  
Chemical Vapor ◽  
Environmental Sensors ◽  
X Ray Diffraction ◽  
Zinc Oxide Nanowires ◽  
Oxide Nanowires ◽  
Current Voltage

ABSTRACTZinc oxide (ZnO) nanowires (NW) are grown on both silicon and sapphire substrates using conventional chemical vapor deposition (CVD) system. As-grown nanostructures are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) as well as energy dispersive spectroscopy (EDS) and the results confirm high-quality c-axis growth of single-crystalline zinc oxide nanowires. Nanowire are dispersed in solvent and then placed between micro-patterned gold electrodes fabricated on silicon wafers using low cost and scalable dielectrophoresis (DEP) process for fabrication of oxygen and humidity sensors. These sensors are characterized in a vacuum chamber connected to a semiconductor analyzer. Current-voltage characteristics of each device are systematically investigated under different hydrostatic pressure of various gaseous environments such as nitrogen, argon, dry and humid air. It is observed that the electrical conductivity of the nanowires is significantly dependent on the number of oxygen and water molecules adsorbed to the surface of the metal oxide nanowire. These results are critical for development of low cost metal oxide sensors for high performance ubiquitous environmental sensors of oxygen and humidity.

Novel Red-Orange Phosphors Na2BaMg(PO4)2:Pr3+: Synthesis, Crystal Structure and Photoluminescence Performance

2018 ◽  
Vol 73 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Lu Pan ◽  
Xiaozhan Yang ◽  
Chaoyue Xiong ◽  
Dashen Deng ◽  
Chunlin Qin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Solid State Lighting ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Hexagonal Cell ◽  
X Ray ◽  
Trigonal System ◽  
Chromaticity Coordinates

AbstractA series of new red-orange emission phosphors Na2BaMg(PO4)2:Pr3+ were synthesised by a high-temperature solid-state reaction. The crystal structure and photoluminescence properties of these samples were characterised by X-ray diffraction and spectroscopic measurements. This compound holds P3̅m1 space group of the trigonal system with the lattice parameters of hexagonal cell a=0.5304(3) nm and c=0.6989(3) nm. The phosphor emits the strongest peak at 606 nm when excited by 449 nm. The average Commission Internationale de l’Eclairage chromaticity coordinates calculated for the phosphors are (0.52, 0.46). The results demonstrate the potential application of these phosphors in solid-state lighting and other fields.

scholarly journals Environment-dependent Emission Tuning in the Multicolor Nitrogen-doped Carbon Quantum Dots

2021 ◽  
Author(s):  
Dineshkumar Sengottuvelu ◽  
Abdul Kalam Shaik ◽  
Satish Mishra ◽  
Mahsa Abbaszadeh ◽  
Nathan Hammer ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solid State ◽  
Large Scale ◽  
Low Cost ◽  
Visible Region ◽  
Carbon Quantum Dots ◽  
One Pot ◽  
Nitrogen Doped ◽  
Emission Changes ◽  
Nitrogen Doped Carbon

Carbon quantum dots (CQDs) are fascinating luminous materials from the carbonaceous family and are increasingly being investigated in many optoelectronic applications due to their unique photoluminescence (PL) characteristics. Herein, we report the synthesis of nitrogen-doped carbon quantum dots (NCQDs) from citric acid and m-phenylenediamine using a one-pot hydrothermal approach. The environment-dependent emission changes of NCQDs were extensively investigated in various solvents, in solid-state, and in physically assembled PMMA-PnBA-PMMA copolymer gels in 2-ethyl hexanol. The NCQDs display bright emission in various solvents as well as in solid-state and a temperature-dependent enhanced emission in gels. In detail, these NCQDs exhibit multicolor PL emission across the visible region and its enhancement upon changing the environment (solutions and polymer matrices). The NCQDs also exhibit excitation-dependent PL and solvatochromism, which are rarely observed in CQDs. Most CQDs are non-emissive in the aggregated or solid-state due to the aggregation-caused quenching (ACQ) effect, limiting their solid-state applications. However, these NCQDs display a strong solid-state emission centered at 568 nm ascribed to the presence of abundant surface functional groups, which helps to prevent the - interaction between the NCQDs and to overcome the ACQ effect in the solid-state. Interestingly, the NCQD containing gels display a significant fluorescence enhancement than the NCQDs in 2-ethyl hexanol solution because of the interaction between the polar PMMA blocks and NCQDs. This research opens up the development of large-scale, low-cost multicolor phosphor for the fabrication of optoelectronic devices, sensing, and bioimaging applications.

Alaska’s Renewables-Source Fuel Energy Storage Pilot Plant: Toward Community Energy Independence via Solid State Ammonia Synthesis (SSAS)

2013 ◽  
Author(s):  
William C. Leighty
Keyword(s):  
Energy Storage ◽  
Solid State ◽  
Large Scale ◽  
Ammonia Synthesis ◽  
Low Cost ◽  
High Energy ◽  
High Energy Density ◽  
Energy Needs ◽  
Steel Tanks ◽  
Energy Independence

Alaska village survival is threatened by the high cost of imported fuels for heating, electricity generation, and vehicles. During Winter 2007–8, the price per gallon of heating oil and diesel generation fuel exceeded $8 in many villages. Many villagers were forced to move to Anchorage or Fairbanks. Although indigenous renewable energy (RE) resources may be adequate to supply a community’s total annual energy needs, the innate intermittent and seasonal output of the renewables — except geothermal, where available, which may be considered “baseload” — requires large-scale, low-cost energy storage to provide an annually-firm energy supply. Anhydrous ammonia, NH3, is the most attractive, carbon-free fuel for this purpose at Alaska village scale, because of its 17.8% mass hydrogen content and its high energy density as a low-pressure liquid, suitable for storage in inexpensive mild steel tanks. NH3 may be synthesized directly from renewable-source electricity, water, and atmospheric nitrogen (N2) via solid state ammonia synthesis (SSAS), a new process to be pioneered in Alaska.

scholarly journals New solid-state organic scintillators for fast and thermal neutron detection

2020 ◽  
Vol 50 ◽  
pp. 2060003
Author(s):  
N. Zaitseva ◽  
A. Glenn ◽  
A. Mabe ◽  
L. Carman ◽  
S. Payne
Keyword(s):  
Solid State ◽  
Large Scale ◽  
Low Cost ◽  
Neutron Detection ◽  
Pulse Shape Discrimination ◽  
Fast Neutrons ◽  
Solution Technique ◽  
Thermal Neutrons ◽  
Different Types ◽  
Fast Neutron Detection

Detection of special nuclear materials (SNM) requires instruments that can detect and characterize uranium and plutonium isotopes, having at the same time the ability to discriminate among different types of radiation. For many decades, neutron detection has been based on 3He proportional counters sensitive primarily to thermal neutrons. The most common methods for detection of fast neutrons have been based on liquid scintillators with pulse shape discrimination (PSD). The shortage of 3He and handling issues with liquid scintillators stimulated a search for efficient solid-state PSD materials. Recent studies conducted at LLNL led to development of new materials, among which are organic crystals with excellent PSD and first PSD plastics for fast neutron detection. More advantages are introduced by plastics doped with neutron capture agents, such as 10B and 6Li, that can be used without moderation for combined detection of both thermal and fast neutrons, offering, in addition, a unique “triple” PSD for signal separation between fast neutrons, thermal neutrons, and gamma-rays. More recent studies have been focused on development of deuterated scintillators that can be used for neutron spectroscopy without time-of-flight (ToF). Among commercially produced materials are large-scale (>10 cm) stilbene crystals grown by the inexpensive solution technique, and different types of PSD plastics that, due to the deployment advantages and ease of fabrication, create a basis for the widespread use of solid-state scintillators as large-volume and low-cost neutron detectors.

A Sample Holder for X-Ray Powder Diffraction Studies of Flakiness and Block Sample

2013 ◽  
Vol 544 ◽  
pp. 433-436
Author(s):  
Hua Yong Zhang ◽  
Xiao Jian Liu ◽  
Hai Yan Sun ◽  
Chun Sheng Fan
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Low Cost ◽  
Sample Holder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Block Sample ◽  
Powder Diffractometer ◽  
Analytical Results ◽  
Sample Carrier

Powder X-ray diffraction (XRD) is one of the primary techniques used to characterize solid state materials. But there is not a sample holder which can be fit into the sample carrier of the Bruker D8-Advance x-ray powder diffractometer for flakiness and block samples test. In this article, we will design, manufacture and evaluate a sample holder for flakiness and block samples. Materials of the holder are steel, glass and plasticine etc. The holder is low cost, easy to be processed, convenience to prepare the samples, and accurately obtain the best analytical results.

scholarly journals Production of Fungal Laccase under Solid State Bioprocessing of Agroindustrial Waste and Its Application in Decolourization of Synthetic Dyes

2019 ◽  
pp. 1-17
Author(s):  
Benjamin Vandelun Ado ◽  
Abiodun Anthony Onilude ◽  
Hyacinth Ocheigwu Apeh Oluma ◽  
Daniel Malo Mabitine
Keyword(s):  
Solid State ◽  
Large Scale ◽  
Specific Activity ◽  
Low Cost ◽  
Laccase Production ◽  
Synthetic Dyes ◽  
Phenol Red ◽  
Redox Potentials ◽  
Agroindustrial Waste ◽  
Optimum Production

Fungal laccases are preferred due to high redox potentials and low substrate specificity to xenobiotics including synthetic dyes. For large-scale applications, low enzyme yield and high cost of production has remained the challenge. Agroindustrial waste such as saw-dust of Terminalia superba abounds locally and was utilized as low-cost alternative substrate for laccase production in Solid State Bioprocessing (SSB) using Trametes sp. isolate G31. The study optimized laccase production using various parameters. Optimal production of laccase was at pH 5.0 - 7.0 with 2356 U/mL - 2369 U/mL and 25°C (2336 U/mL). Among the sources of nitrogen and carbon tested, laccase production in ammonium sulphate and sucrose supplemented media were higher. The effect of activators on laccases production showed that Cu2+ and Ca2+induced high titres of laccase at 4 -5 mM and 2 - 4 mM respectively, while production of laccase by Mn2+ was significantly high at 40 mM. The effect of 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), guaiacol and varatryl alcohol on laccase production was significantly different especially in glycerol. Optimum production for laccase was on day 14 with 2356 U/mL followed by steady declined up to day 34. The purified laccase had a specific activity of 5008 µmol/min/mg, purification factor of 3.85, and a molecular mass of ~40 kDa using N-PAGE. The potential of crude laccase to decolourize diverse dyes was tested. Phenol red achieved 40% decolourization for 1hr, while RBBR (93%), Crystal violet (60%), Methylene blue (53%) and Congo red (51%) for 24 hr, 72 hr, 48 hr and 120 hr respectively. Methyl red and Malachite green attained 42% (72 hr) and 32% (48 hr) decolourization. The enzyme ability to oxidize Phenol red and other synthetic dyes without mediators made it eco-friendly in treating dye wastewaters.

scholarly journals BIOLOGICAL SYNTHESIS OF KERATIN NANOPARTICLES FROM DOVE FEATHER (COLUMBA LIVIA) AND ITS APPLICATIONS

2019 ◽  
pp. 142-146
Author(s):  
NANTHAVANAN P ◽  
KANDASAMY ARUNGANDHI ◽  
SUNMATHI D ◽  
NIRANJANA J
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Visible Spectrum ◽  
Columba Livia ◽  
Salmonella Typhi ◽  
Biological Synthesis ◽  
X Ray Diffraction ◽  
Zone Of Inhibition ◽  
X Ray ◽  
Synthesis Of Nanoparticles

Objectives: The aim of the present study was to synthesize keratin nanoparticles from dove feathers. Methods: Crude keratin was extracted by chemical method. The protein content was estimated by Lowry’s method and it was found to be 0.18 mg/ml. The keratin nanoparticles were obtained using glutaraldehyde as cross-linking agent. Results: A single peak maximum at 270 nm corresponds to the surface plasmon resonance of keratin nanoparticles was observed in the ultraviolet-visible spectrum. The size of keratin nanoparticles was 78 nm. The crystalline size of keratin nanoparticles was 79.6 nm and it was obtained by X-ray diffraction. The antibacterial activity of crude keratin and keratin nanoparticles was determined which revealed that keratin nanoparticles showed higher zone of inhibition than crude keratin protein against Staphylococcus aureus and Salmonella typhi. Keratin nanoparticles showed higher antioxidant activity than crude keratin. Conclusion: Biological synthesis of nanoparticles has many advantages such as ecofriendly and low cost and can be synthesized in large scale. The keratin nanoparticles can be applied in wound dressing, biosorbent, and cosmetics.

scholarly journals Preliminary results on the preparation of carbon nanotubes using arc discharge in water medium

2020 ◽  
pp. 26-30
Author(s):  
Ulambayar R ◽  
Dawaabal B ◽  
Oyun-Erdene G ◽  
J Temuujin
Keyword(s):  
Carbon Nanotubes ◽  
Large Scale ◽  
Arc Discharge ◽  
Low Cost ◽  
Water Medium ◽  
X Ray Diffraction ◽  
Plastic Container ◽  
Graphite Electrodes ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Depending on the application, carbon nanotubes are being intensively studied in physics, chemistry, medicine, and computers. Therefore, it is important to develop large-scale high-quality multi-walled carbon nanotubes production at low cost. Wehere conducted a study on the easy preparation of low-cost carbon nanotubes. Two graphite electrodes were placed vertically in a thick, clear plastic container with distilled water to produce a carbon nanotube with an alternating current arc. The device has a simple design and the water acts as an insulating medium and cools the system. X-ray diffraction (XRD) and infrared spectrum (FTIR) analysis of the obtained carbon soot was performed in comparison with technical multi-walled carbon nanotubes. These tests confirmed that the multi-walled carbon nanotubes were formed during the experiment. Нуман цахилалтын аргаар усан орчинд нүүрстөрөгчийн нано хоолой гарган авах урьдчилсан судалгаа Хураангуй: Нүүрстөрөгчийн нано хоолойг хэрэглээнээс хамаарч физик, хими, анагаах ухаан, компьютер гэх зэрэг салбаруудад эрчимтэй судлаж байна. Иймээс ч өндөр чанартай олон ханатай нүүрстөрөгчийн нано хоолойг бага зардлаар их хэмжээтэй, гарган авах арга техникийг хөгжүүлэх нь нэн чухал юм. Бид бага зардлаар нүүрстөрөгчийн нано хоолойг хялбараар гарган авах судалгааг явууллаа. Нэрмэл ус бүхий зузаан тунгалаг хуванцар саванд бал чулуун хоёр электродыг босоо хэлбэртэй байрлуулан хооронд нь хувьсах гүйдлийн нуман цахилалт цахилуулан нүүрстөрөгчийн нано хоолойг гарган авсан. Энэхүү төхөөрөмж нь энгийн хялбар хийцтэй бөгөөд ус нь тусгаарлагч орчин болж, системийг хөргөдөг. Гарган авсан нүүрстөрөгчийн хөөнд рентген дифракцийн (XRD) болон нил улаан туяаны спектрийн (FTIR) шинжилгээг техникийн олон ханатай нүүрстөрөгчийн нано хоолойтой харьцуулан хийж гүйцэтгэсэн. Эдгээр шинжилгээгээр олон ханатай нүүрстөрөгчийн нано хоолой туршилтын явцад үүссэн болохыг баталлаа. Түлхүүр үг: Нуман цахилалт, нүүрстөрөгчийн нано хоолой, графен, графит (бал чулуу)

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