Photoluminescence abbreviated as PL is a process in which a substance absorbs photons electromagnetic radiation and then re radiates photons. quantum mechanics Quantum mechanically , this can be described as an Quantum jump excitation to a higher energy level energy state and then a return to a lower energy state accompanied by the emission of a photon. This is one of many forms of luminescence light emission and is distinguished by photoexcitation excitation by photons , hence the prefix photo . ref GoldBookRef title photochemistry file P04588 ref The period between absorption and emission is typically extremely short, in the order of 10 nanosecond s. Under special circumstances, however, this period can be extended into minutes or hours. Forms of photoluminescence The simplest photoluminescent processes are resonant radiations , in which a photon of a particular wavelength is absorbed and an equivalent photon is immediately emitted. This process involves no significant internal energy transitions of the chemical substrate between absorption and emission and is extremely fast, of the order of 10 nanoseconds. More interesting processes occur when the chemical substrate undergoes internal energy transitions before re emitting the energy from the absorption event. The most familiar ... diagram shows. Photoluminescence is an important technique for measuring the purity and crystalline quality of semiconductors such as GaAs and InP . Several variations of photoluminescence exist, including photoluminescence excitation PLE . Time resolved photoluminescence TRPL is a method where the sample is excited with a light pulse and then the decay in photoluminescence with respect to time ... like Gallium arsenide GaAs . An even more specialized form of photoluminescence is phosphorescence ... detection In phosphor thermometry , the temperature dependence of the photoluminescence process ... Spektroskopie et Fotoluminestsents fr Photoluminescence it Fotoluminescenza lv Fotoluminiscence mk ... more details
orphan date May 2010 unreferenced date October 2009 Photoluminescence excitation PLE is a specific type of photoluminescence and concerns the interaction between electromagnetic radiation and matter . In a quantum mechanic description, matter is made of quantum systems atoms and molecules . In quantum mechanics a quantum system is described as having possible states . There are systems with a continuous range of possible states, and system with a discrete range of states. As an example, we can consider the electrons in an atom. Since the electrons of an atom are not free particles, but are confined in the system, the possible states of the electrons are discrete . To better explain what discrete means, we have to consider that each state is labelled by one or more parameters. In other words to individuate a state we specify the value of one or more parameters, such as energy, velocity, angular momentum, etc. A specific state will have a specific energy, a specific velocity, etc. When a particle is confined, it can be only in some states, with some specific values of energy, jumping from one to the other, and it can not be in a state with an intermediate value of the energy between those forbidden states . When the electromagnetic radiation interacts with a quantum system an atom , it can give it an amount a quantum of energy, and the atom goes from a lower energy state to a higher one excited state . Then, there is the opposite phenomenon, where an atom goes from a higher energy state to a lower one relaxation and emits a quantum of electromagnetic energy in the process. The quantum or packet of energy of the electromagnetic radiation is called a photon. The amount of energy carried by a photon is proportional to its frequency. On the other hand, there is a relationship ... states involved in the jump of the atom. The photoluminescence is then the phenomenon where light is shone ... state to the ground state . In this case we have a non resonant excitation emission photoluminescence ... more details
Glow in the dark may refer to Bioluminescence , the production and emission of light by a living organism Chemiluminescence , is the emission of light luminescence without emission of heat Phosphorescence , a specific type of photoluminescence related to fluorescence Radioluminescence , production of luminescence in a material by the bombardment of ionizing radiation Glow in the Dark Tour , a 2008 concert tour by Kanye West disambiguation ... more details
Degree of polarization DOP is a quantity used to describe the portion of an electromagnetic wave which is Polarization waves polarized . A perfectly polarized wave has a DOP of 100 , whereas an unpolarized wave has a DOP of 0 . A wave which is partially polarized, and therefore can be represented by a superposition of a polarized and unpolarized component, will have a DOP somewhere in between 0 and 100 . DOP is calculated as the fraction of the total power that is carried by the polarised component of the wave. DOP can be used to map the Strain materials science strain field in materials when considering the DOP of the photoluminescence . The polarization of the photoluminescence is related to the strain in a material by way of the given material s photoelasticity tensor . DOP is also visualized using the Polarization waves Parameterization Poincar sphere representation of a polarized beam. In this representation, DOP is equal to the length of the Vector geometric vector measured from the center of the sphere. See also Linear polarization Circular polarization Elliptical polarization Stokes parameters Category Polarization ... more details
PLE may refer to Personal Learning Environment Photoluminescence excitation Pittsburgh and Lake Erie Railroad Polymorphous light eruption , a skin condition caused by sunlight Public legal education Peace Love Ecstasy, a variant of PLUR br the International Olympic Committee country code for the Palestinian territories the International Air Transport Association airport code for Paiela, Papua New Guinea disambig de PLE fr PLE it PLE ja PLE pl PLE ... more details
Multiple issues orphan July 2011 expert December 2010 unreferenced December 2010 notability Products date December 2010 Ceramic impregnated fabrics is a fabric that has been impregnated with ceramic. Nanometric bioceramic can be incorporated into the polymer from which the fabric is manufactured. Bioceramic nanoparticle s are added to the fused polymer. Some types of ceramics show thermally induced photoluminescence , emitting light in the Infrared far infrared FIR region of the electromagnetic spectrum. When in contact with the body heat, the thermoluminescence of the fabrics with embedded bioceramic is enhanced. Bioceramics presents high reflection coefficient for the infrared radiation. Category Ceramics Category Technical fabrics Material stub ... more details
Infobox scientist name Aleksander Jab o ski image a jablonski.jpg caption birth date birth date 26 February 1898 birth place Woskresen wka, then Russian Empire , now Ukraine death date death date and age 9 September 1980 26 February 1898 death place Skierniewice , Poland residence Poland citizenship Poland Polish fields Physics photoluminescence workplaces Humboldt University of Berlin Friedrich Wilhelms Universit t br Nicolaus Copernicus University alma mater Kharkiv University br University of Warsaw known for Jablonski diagram Professor Aleksander Jab o ski born 26 February 1898 in Woskresen wka, in Ukraine , died 9 September 1980 in Skierniewice , Poland was a Polish people Polish physicist and member of the Polish Academy of Sciences . Jablonski received a Ph.D. from the University of Warsaw in 1930, writing a thesis On the influence of the change of the wavelength of excitation light on the fluorescence spectra . Then he went to Humboldt University of Berlin Friedrich Wilhelms Universit t in Berlin , Germany for two years 1930 31 as a fellow of the Rockefeller Foundation . He was working with Peter Pringsheim at the FWU and later with Otto Stern in Hamburg. In 1934 Jablonski returned to Poland to receive habilitation from the University of Warsaw. The habilitation thesis was On the influence of intermolecular interactions on the absorption and emission of light , the subject he would devote the rest of his life to. Jablo ski was one of the pioneers of molecular photophysics, created the concept of the luminescent centre and own theories of concentrational quenching and depolarization of photoluminescence . He was also working on the pressure broadening of the emission spectra lines and was the first person to recognize the analogy between the pressure broadening and molecular spectra. This led to development of the quantum mechanics quantum mechanical pressure broadening theory. Fluorescence is schematically illustrated with the classical Jablonski diagram , f ... more details
Unreferenced date December 2009 Orphan date December 2009 Polypyridine complexes are compounds in which a polypyridine, such as 2,2 bipyridine , 1,10 phenanthroline , or 2,2 6 2 terpyridine , coordinates to a metal Ion physics ion . Polypyridine compounds are multidentate ligand s which have characteristic properties, such as photosensitization. The complexes are very stable to light, electricity, and heat because the bonds between the central metal ion and polypyridine ligands are usually very strong furthermore, the polypyridine itself is generally very stable. The compounds have peculiar optical, electrochemical, and magnetic properties. Some complexes exhibit a strong absorption band in the visible light region, which is called metal to ligand charge transfer MLCT or ligand to metal charge transfer LMCT . The properties of the complexes can be tuned easily by introducing substituents, for example, electron donation, electron withdrawal, and conjugating groups, to the polypyridine Moiety chemistry moiety . The MLCT absorption band can be shifted, the emission wavelength can be changed, and the emission lifetime can be extended. A well known example of a polypyridine complex is rutheniumtris bipyridine , Ru bpy sub 3 sub sup 2 sup . This complex exhibits intense luminescence at room temperature in aqueous solution. Another example is a platinum bipyridine dithiolate complex, Pt bpy bdt , in which bdt denotes a 1,2 benzenedithiolate ion anion . This complex also exhibits Fluorescence photoluminescence at room temperature, and its wavelength and lifetime can be tuned by substitution of either bipyridine or dithiolate moieties. Structural control is easier than for ruthenium complexes due to the square planar structure of the platinum complex. DEFAULTSORT Polypyridine Complex Category Pyridines ... more details
In nanotechnology , nanorods are one morphology of nanoscale objects. Each of their dimensions range from 1&ndash 100 1 E 9 m nm . They may be synthesized from metals or semiconducting materials. Standard aspect ratio image aspect ratio s length divided by width are 3 5. Nanorods are produced by direct chemical synthesis . A combination of ligand s act as shape control agents and bond to different facets of the nanorod with different strengths. This allows different faces of the nanorod to grow at different rates, producing an elongated object. The applications of nanorods are diverse, ranging from display technologies the reflectivity of the rods can be changed by changing their orientation with an applied electric field to microelectromechanical systems MEMS . Nanorods based on semiconducting materials have also been investigated for application as energy harvesting and light emitting devices. In 2006, Ramanathan et. al. demonstrated sup 1 sup electric field mediated tunable photoluminescence from ZnO nanorods, with potential for application as novel sources of near ultraviolet radiation. See also Nanowire Nanopillar Aggregated diamond nanorod External links http www.eetimes.com article showArticle.jhtml?articleID 174900230 Nanorods show negative refraction in near IR EE Times, December 5, 2005 http www.articleworld.org index.php Nanorod Nanorod synthesis and applications http www.springerlink.com content v4h444108k14h670 S. Ramanathan, S. Patibandla, S. Bandyopadhyay, J.D. Edwards, J. Anderson, J. Mater. Sci. Mater. Electron 17, 651 2006 Category Nanomaterials tech stub fr Nanotige nl Nanostaafjes ... more details
Photomedicine is an interdisciplinary branch of medicine that involves the study and application of light with respect to health and disease. Photomedicine may be related to the practice of various fields of medicine including dermatology, surgery, interventional radiology, optical diagnostics, cardiology, and oncology. A branch of photomedicine is light therapy . Examples PUVA for the treatment of psoriasis Photodynamic therapy PDT for treatment of cancer and macular degeneration Photoluminescence Therapy Free electron laser Laser hair removal Photobiomodulation Optical diagnostics, for example optical coherence tomography of coronary artery disease coronary plaques using infrared light Confocal microscopy and fluorescence microscopy of in vivo tissue Diffuse reflectance spectroscopy for in vivo quantification of biological pigment pigments i normal and cancerous , and hemoglobin Perpendicular polarized light polarized flash photography and fluorescence photography of the skin See also Laser hair removal Rox Anderson Blood irradiation therapy External links Journals and Societies http www.photomedicine.org The Photomedicine Society http www.liebertpub.com publication.aspx?pub id 128 Photomedicine and Laser Surgery journal http www.blackwellpublishing.com journal.asp?ref 0905 4383 Photodermatology, Photoimmunology, and Photomedicine Miscellaneous http www.mgh.harvard.edu wellman Wellman Center for Photomedicine at Massachusetts General Hospital Massachusetts General Hospital MGH and Harvard Medical School http www.gfmer.ch Endo Course2003 Photomedicine gynecological oncology.htm Article Role of Photomedicine in Gynecological Ontology med stub Category Medical specialties Category Medical physics Category Laser medicine Category Light therapy no Fotomedisin ... more details
to the term anti Stokes photoluminescence in materials science including semiconductors http www.google.co.uk search?q 22Anti Stokes photoluminescence 22 see examples . Equal terminology in use ... more details
wiktionary pl Pl PL PL , P.L. , Pl , or Pl. may refer to TOC right Politics, law and philosophy Pl., an abbreviation for Plural Partido Laborista disambiguation Partido Laborista Patrologia Latina Philippine Legislature , a legislature that existed in the Philippines from 1907 to 1935 PL Kyodan , a religious movement founded in Japan in the early 20th Century Poland , ISO 3166 1 country code Polish language , ISO 639 1 code Private label Progressive Labor Party United States Progressive Labor Party , a United States communist party Propositional logic , a system of evaluating truth based propositions in terms of binary logic Public library Public law Public liability PL postcode area , a group of postcode districts in England Science, aviation and military PL tone Pluto , a dwarf planet discovered by Percival Lowell Patriotic League Bosnian Patriotska Liga , a first military organisation of Republic of Bosnia and Herzegovina Photoluminescence Piecewise linear Pierre Levasseur aircraft builder Pierre Levasseur , a French aircraft designer Platoon Leader in the United States Army Plastic limit in geotechnical engineering Path loss in telecommunication engineering Pulchellidin Pl , an anthocyanidin Airstars Airways , IATA airline designators PL AeroPeru , IATA airline designators PL Ice pellets , METAR Code PL Digital Private Line Two variants of litre , picolitre pL and petaliter PL Computing and internet tt .pl tt , country code top level domain for Poland tt .pl tt , common filename suffix for Perl scripts tt .pl tt , common filename suffix for Prolog programs tt .pl tt , common filename suffix for TeX font metric TeX font property lists PL C PL I PL SQL Packet loss Procedural programming Programming language Presentation Layer Sports Pioneer Baseball League , a Rookie league in Minor League Baseball Pioneer Football League , NCAA FCS conference Premier League , the top English football league Pacific League , one of the two leagues in Japan s Nippon Professional Ba ... more details
Image E27 with 38 LCD.JPG thumb 200px LED lamp with E27 Edison screw . Solid state lighting SSL refers to a type of lighting that uses light emitting diode semiconductor light emitting diode s LEDs , organic light emitting diode s OLED , or polymer light emitting diode s PLED as sources of illumination rather than electrical filament s, Plasma physics plasma used in arc lamps such as fluorescent lamps , or gas lighting gas . The term Solid state electronics solid state refers commonly to light emitted by solid state electroluminescence, as opposed to incandescent bulbs which use thermal radiation or fluorescent tubes. Compared to incandescent lighting, SSL creates visible light with reduced heat generation or parasitic energy dissipation. Most common white LEDs convert blue light from a solid state device to an approximate white light spectrum using photoluminescence, the same principle used in conventional fluorescent tubes. The typically small mass of a solid state electronic lighting device provides for greater resistance to shock and vibration compared to brittle glass tubes bulbs and long, thin filament wires. They also eliminate filament evaporation, potentially increasing the service life life span of the illumination device. Solid state lighting is often used in traffic light s and is also used frequently in modern vehicle lights, street and parking lot lights, train marker lights, building exteriors remote controls etc. ref http sustainca.org techshowcase ssl case studies California Sustainability Alliance Solid State Lighting , Received July 24th, 2010 ref See also LED lamp List of light sources L Prize Nonimaging optics References reflist External links Commons category LED lamps http www.netl.doe.gov ssl strategy.html DOE SSL roadmap http www.solidstatelighting.org Solid State Lighting.org http scitation.aip.org journals doc PHTOAD ft vol 54 iss 12 42 1.shtml The Promise and Challenge of Solid State Lighting http www.lrc.rpi.edu programs solidstate index ... more details
nofootnotes date December 2010 refimprove date December 2010 Image FRET Jablonski diagram.jpg 400 px thumb A Jablonski diagram representing F rster resonance energy transfer FRET A Jablonski diagram , named after the Polish physicist Aleksander Jab o ski , is a diagram that illustrates the electronic state s of a molecule and the transitions between them. The states are arranged vertically by energy and grouped horizontally by term symbol spin multiplicity . Conical intersection Nonradiative transitions are indicated by squiggly arrows and Photoluminescence radiative transitions by straight arrows. The vibrational ground states of each electronic state are indicated with thick lines, the higher vibrational states with thinner lines. Transitions Radiative transitions involve the absorption, if the transition occurs to a higher energy level, or the emission, in the reverse case, of a photon . Nonradiative transitions arise through several different mechanisms, all differently labeled in the diagram. Relaxation of the excited state to its lowest vibrational level is labeled Vibrational energy relaxation vr in the diagram. This process involves the dissipation of energy from the molecule to its surroundings, and thus it cannot occur for isolated molecules. A second type of nonradiative transition is Internal conversion chemistry internal conversion ic , which occurs when a vibrational state of an electronically excited state can couple to a vibrational state of a lower electronic state. A third type is intersystem crossing isc this is a transition to a state with a different spin multiplicity. In molecules with large Angular momentum coupling spin orbit coupling , intersystem crossing is much more important than in molecules that exhibit only small spin orbit coupling. This type of nonradiative transition can give rise to phosphorescence . See also Spectroscopy Franck Condon principle References Elumalai, P., Atkins, P., de Paula, J. Atkins Physical Chemistry , Oxford U ... more details
Image Phosphorescent.jpg thumb Europium doped strontium silicate aluminate oxide powder under visible light, long wave UV light, and in total darkness. Image Luminescent paint pigment applied on a diver s watch to make it readable in low light conditions..jpg thumb Lume applied on a diver s watch to make it readable in low light conditions. Super LumiNova is a brand name under which strontium aluminate based non radioactive and non toxic photoluminescence photoluminescent or afterglow pigments for illuminating markings on watch dials, hands and bezels, etc. in the dark are marketed. This technology offers up to 10 times better brightness than previous zinc sulphide based materials. Besides for timepieces Super LumiNova is also marketed for application on Instruments scales, dials, markings, indicators etc. Scales engravings, silkscreen printing Aviation instruments and markings Jewellery Safety and emergency panels, signs, markings Aiming posts and Various other parts This type of phosphorescence phosphorescent pigments, often called lume , operate like a light battery. After sufficient activation by sunlight or artificial light, they glow in the dark for hours. Larger markings are visible for the whole night. This activation and subsequent light emission process can be repeated again and again, and the material does not suffer any practical aging. Strontium aluminate based pigments have to be protected against contact with water or moisture, since this degrades the light emitting quality. ref http www.rctritec.com index.php?id 13 RC TRITEC Super LumiNova ref ref http www.nemoto.co.jp en products luminova index.html Nemoto & Co., Ltd LumiNova ref ref http www.glowinfo.com glow in the dark glow in the dark technology.html Glow in the Dark Phosphorescent Technologies ref File Luminova.JPG 500px LumiNova pigments in the dark Alternative for afterglow pigments Tritium Self powered lighting Tritium based devices called gaseous tritium light source GTLS , that are an alte ... more details
Orphan date February 2009 Jorg Wrachtrup is a physicist who while working on his PhD thesis carried out the first electron spin resonance experiments on single electron spins. ref J. Wrachtrup et al. Nature 363 1993 244 ref The work was done in close collaboration with and in the lab of M. Orrit at the CNRS Bordeaux. In the course of these studies also the first coherent experiments on single electron spins in a solid were successful. In subsequent investigations even electron nuclear double resonance which mark the first experiments on single nuclei has been achieved. While working at the Chemnitz University of Technology , he headed a research team that has, for the first time, detected the optical signal of a single defect center. The particular defect was the nitrogen vacancy center N V in diamond . ref A. Gruber et al. Science 276 1997 2012 ref This pioneering work has created standards for numerous follow up studies of individual N V centers aiming at manipulations of individual nuclear spins in solids quantum computer . All of the above achievements combined the following essential elements 1 N V centers were produced in sufficiently low concentrations, so that separation between the centers exceeded several micrometers, and individual centers could be detected using a conventional scanning confocal optical microscope . 2 Photoluminescence and electron paramagnetic resonance techniques were combined into optically detected magnetic resonance, detected from a single center. The authors of the paper being experience in single molecule magnetic resonance deliberately were choosing a defect center with an electron paramagnetic ground state. By this they achieved room temperature single electron spin resonance. In addition the defect center proved to be unconditionally photostable, in contrast to most other single quantum emitters. This discovery is the basis for numerous applications of defects in diamond as single photon source, quantum register and in magnetome ... more details
Metalloles are Inorganic chemistry inorganic derivatives of cyclopentadiene in which the carbon atom at position 5, the saturated carbon, is replaced by an inorganic atom. In contrast to its parent compound, the numbering of the metallole starts at the heteroatom . Some of these compounds are described as organometallic compounds, but in the list below quite a number of metalloid s are present too. ref cite journal last1 Tracy first1 Henry J. last2 Mullin first2 Jerome L. last3 Klooster first3 Wim T. last4 Martin first4 James A. last5 Haug first5 Judith last6 Wallace first6 Scott last7 Rudloe first7 Isaac last8 Watts first8 Kimberly title Enhanced Photoluminescence from Group 14 Metalloles in Aggregated and Solid Solutions journal Inorganic Chemistry volume 44 issue 6 pages 2003 year 2005 pmid 15762727 doi 10.1021 ic049034o ref Many metalloles are fluorescent and are used in organic light emitting diodes OLEDs and other applications. Metalloles, which can also be viewed as structural analog s of pyrrole , include class wikitable style text align center float right margin left 0.5em Calculated geometry and inversion barrier energy E for some C sub 4 sub H sub 4 sub MH metalloles ref name geo cite journal last1 Pelzer first1 Silke last2 Wichmann first2 Karin last3 Wesendrup first3 Ralf last4 Schwerdtfeger first4 Peter title Trends in Inversion Barriers IV. The Group 15 Analogous of Pyrrole journal The Journal of Physical Chemistry A volume 106 pages 6387 year 2002 doi 10.1021 jp0203494 ref Name M d M C , ngstr m d M H , C M C , E , kJ mol Pyrrole N 1.37 1.01 110 0 Phosphole P 1.81 1.425 90.5 67 Arsole As 1.94 1.53 86 125 Stibole Sb 2.14 1.725 80.5 160 Bismole Bi 2.24 1.82 78 220 Arsole , a moderately aromatic arsenic analog Bismole , a bismuth analog Borole , a boron analog Gallole , a gallium analog Germole , a germanium analog Phosphole , a phosphorus analog Plumbole , a lead analog Pyrrole , a nitrogen analog Selenophene , a selenium analog Silole , a silico ... more details
orphan date December 2009 The purpose of this article is to summarize the methods used to experimentally characterize a semiconductor material or Semiconductor device device PN junction , Schottky diode , etc. . Some examples of semiconductor quantities that could be characterized include depletion width , carrier concentration, optical generation and Recombination physics recombination rate, carrier lifetime s, defect concentration, trap states, etc. These quantities fall into three categories when it comes to characterization methods 1 Electrical Characterization 2 Optical Characterization 3 Physical Chemical Characterization Electrical Characterization Techniques Electrical Characterization can be used to determine resistivity , carrier concentration, mobility, contact resistance , barrier height, depletion width, oxide charge, interface states, carrier lifetimes, and deep level impurities. Two Point Probe, Four Point Probe, Differential Hall Effect, Capacitance voltage profiling Capacitance Voltage Profiling , Deep level transient spectroscopy DLTS , and DLCP. Optical Characterization Optical Characterization may include microscopy , ellipsometry , photoluminescence , transmission spectroscopy, absorption spectroscopy , raman spectroscopy , reflectance modulation, cathodoluminescence , to name a few. Physical Chemical Characterization Electron beam Electron Beam Techniques SEM, TEM, AES, EMP, EELS Ion beam Ion Beam Techniques Sputtering , SIMS, RBS X ray X Ray Techniques XRF, XPS, XRD, X ray topography Neutron activation analysis Neutron Activation Analysis NAA Chemical etching Chemical Etching Future Characterization Methods Many of these techniques have been perfected for silicon making it the most studied semiconductor material. This is a result of silicon s affordability and prominent use in computing . As other fields such as power electronics , Light emitting diode LED devices , photovoltaics , etc. begin to come of age, characterization of a variety of al ... more details
. Image EF 605 spectra.png right 500px Extinction and photoluminescence spectra for eFluor 605 nanocrystals ... and concentration for most quantum dots. The photoluminescence spectra of quantum dots are also unique ... to the spectrum. The width of the photoluminescence peak represents the heterogeneity in size dispersion ... more details
photoluminescence , PL or electron beam cathodoluminescence , CL , and absorption of light in the IR .... Preferential alignment of Er 2O centers in GaAs revealed by anisotropic host excited photoluminescence ... S. Lal et al. Defect photoluminescence in polycrystalline diamond films grown by arc jet chemical vapor ... right 180px Image diaPL1.jpg thumb right 180px A micrograph top and UV excited photoluminescence bottom ... hyperfine structure in electron paramagnetic resonance , optical absorption and photoluminescence ... by electron paramagnetic resonance , ref name align ref name nadol optical absorption and photoluminescence ... 10.1103 PhysRevB.61.9 Phys. Rev. B 61 2000 9 ref and photoluminescence , ref name align ref S.C. Lawson ... and unlike most other defects in diamond, it does not produce photoluminescence . Interstitial complexes .... B 62 2000 6587 ref optical absorption and photoluminescence. ref name pb Vacancy Interstitial complexes ... 12900 ref Similar to single interstitials, divacancies do not produce photoluminescence. Divacancies ..., University of Cambridge Cambridge, England. ref Broadband blue photoluminescence has been reliably ... 10.1080 014186398258104 Phil. Mag. B 78 1998 299 ref As with dislocations, a broad photoluminescence ... more details
al. title Cross Polarized Optical Absorption of Single Walled Nanotubes Probed by Polarized Photoluminescence ... significant overlap occurs in absorption spectra. This overlap is avoided in photoluminescence ... nanotubes, such as bundling, broaden optical lines. While bundling strongly affects photoluminescence ... IR gallery Luminescence Image PLmap1.jpg thumb 420px Photoluminescence map from single wall carbon ... do not detect nanotubes with n m or m 0. Excitation mechanism Photoluminescence PL is one of the important .... Therefore no exciton is produced. Salient properties Photoluminescence from SWCNT, as well as optical ... cite journal author K. Iakoubovskii et al. title IR Extended Photoluminescence Mapping of Single Wall ... chirality bundles as the photoluminescence spectrum displays a splitting consistent with intertube ... show PL only from the outer shells. ref cite journal author T. Okazaki et al. title Photoluminescence ... spectrum, as discussed below. Similar to photoluminescence mapping, the energy of the excitation light ... more details
Image Phosphorescent.jpg thumb Europium doped strontium silicate aluminate oxide powder under visible light, long wave UV light, and in total darkness. Strontium aluminate SRA , SrAl , Strontium Aluminum sub 2 sub Oxygen sub 4 sub is a solid odorless, nonflammable, pale yellow powder, heavier than water. It is chemically and biologically inert. When activator phosphor activated with a suitable dopant e.g. europium , then it is labeled SrAl sub 2 sub O sub 4 sub Eu , it acts as a photoluminescence photoluminescent phosphor with long persistence of phosphorescence . Its CAS number is CASREF CAS 12004 37 4 . Strontium aluminate is a vastly superior phosphor to its predecessor, copper activated zinc sulfide it is about 10 times brighter and 10 times longer glowing, however about 10 times more expensive than ZnS Cu. It is frequently used in Phosphorescence glow in the dark toys, where it displaces the cheaper but less efficient ZnS Cu. However, the material has high hardness, causing abrasion to the machinery handling it coating the particles with a suitable lubricant is usually used when strontium aluminate is added to plastic s. Strontium aluminate phosphors produce green and aqua hues, where green gives the highest brightness and aqua the longest glow time. The excitation wavelengths for strontium aluminate range from 200 to 450 nm. The wavelength for its green formulation is 520 nm, its blue green version emits at 505 nm, and the blue one emits at 490 nm. Colors with longer wavelengths can be obtained from the strontium aluminate as well, though for the price of some loss of brightness. The wavelengths produced depend on the internal crystal structure of the material. Slight modifications in the manufacturing process the type of reducing atmosphere, small variations of stoichiometry of the reagents, addition of carbon or rare earth halide s can significantly influence the emission wavelengths. Strontium aluminate phosphor is fired at about 1250&nb ... more details
Encyclopedia
top
