Self-absorption correction for solid-state photoluminescence quantum yields obtained from integrating sphere measurements

2007 ◽  
Vol 78 (8) ◽  
pp. 086105 ◽  
Author(s):  
Tai-Sang Ahn ◽  
Rabih O. Al-Kaysi ◽  
Astrid M. Müller ◽  
Katherine M. Wentz ◽  
Christopher J. Bardeen
Keyword(s):  
Solid State ◽  
Quantum Yields ◽  
Integrating Sphere ◽  
Absorption Correction

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

scholarly journals A rapid microwave synthesis of green-emissive carbon dots with solid-state fluorescence and pH-sensitive properties

2018 ◽  
Vol 5 (7) ◽  
pp. 180245 ◽  
Author(s):  
Tingting Yu ◽  
Haijiao Wang ◽  
Chongzheng Guo ◽  
Yanli Zhai ◽  
Jianzhou Yang ◽  
...  
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Phthalic Acid ◽  
Chemical Properties ◽  
Carbon Quantum Dots ◽  
Feed Ratio ◽  
Quantum Yields ◽  
Ph Sensing ◽  
Wavelength Emission ◽  
Physical And Chemical

The emerging carbon quantum dots (CQDs) have been attracting significant attention for their prominent fluorescence, excellent stability and outstanding biocompatibility. Here, we report a facile one-step synthesis of highly fluorescent CQDs by using phthalic acid and triethylenediamine hexahydrate as precursors through a simple microwave-assisted method. The reaction time needed is only 60 s, which is less time-consuming than most previous reports. The phthalic acid with a benzene ring can improve the photoluminescence properties of CQDs as it can provide foreign sp 2 conjugating units, and then finally result in long-wavelength emission. The synthesized CQDs were fully characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Besides, the impacts of different freed ratio on physical and chemical properties of CQDs were investigated in detail. The prepared CQDs exhibited strong green fluorescence with a broad maximum emission wavelength. The quantum yields of the CQDs can reach 16.1% in aqueous solution and they were successfully used in cell imaging with good biocompatibility. Moreover, in solid state, the CQDs with the feed ratio of 1 : 0.5 showed a strong green–yellow fluorescence which may have great potential to fabricate optoelectronic devices. Furthermore, the prepared CQDs also showed high pH sensitivity and can act as a fluorescence nanosensor for pH sensing.

scholarly journals Nitrile-Substituted 2-(Oxazolinyl)-Phenols: Minimalistic Excited-State Intramolecular Proton Transfer (ESIPT)-Based Fluorophores

2020 ◽  
Author(s):  
Dominik Göbel ◽  
Daniel Duvinage ◽  
Tim Stauch ◽  
Boris Nachtsheim
Keyword(s):  
Excited State ◽  
Solid State ◽  
Proton Transfer ◽  
Density Functional ◽  
Intramolecular Proton Transfer ◽  
Crystal Structure Analysis ◽  
Quantum Yields ◽  
Functional Theory ◽  
Emission Properties ◽  
Emission Enhancement

Herein, we present minimalistic single-benzene, excited-state intramolecular proton transfer (ESIPT) based fluorophores as powerful solid state emitters. The very simple synthesis gave access to all four regioisomers of nitrile-substituted 2(oxazolinyl)phenols (MW = 216.1). In respect of their emission properties they can be divided into aggregation-induced emission enhancement (AIEE) luminophores (1-CN and 2-CN), dual state emission (DSE) emitters (3-CN) and aggregation-caused quenching (ACQ) fluorophores (4‐CN). Remarkably, with compound 1-CN we discovered a minimalistic ESIPT based fluorophore with extremely high quantum yield in the solid state ΦF = 87.3% at λem = 491 nm. Furthermore, quantum yields in solution were determined up to ΦF = 63.0%, combined with Stokes shifts up till 11.300 cm–1. Temperature dependent emission mapping, crystal structure analysis and time-dependent density functional theory (TDDFT) calculations gave deep insight into the origin of the emission properties.<br>

scholarly journals Towards Blue AIE/AIEE: Synthesis and Applications in OLEDs of Tetra-/Triphenylethenyl Substituted 9,9-Dimethylacridine Derivatives

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 445 ◽  
Author(s):  
Monika Cekaviciute ◽  
Aina Petrauskaite ◽  
Sohrab Nasiri ◽  
Jurate Simokaitiene ◽  
Dmytro Volyniuk ◽  
...  
Keyword(s):  
Solid State ◽  
Quantum Yields ◽  
Yellow Emission ◽  
Blue Color ◽  
Television System ◽  
Fluorescence Quantum Yields ◽  
Deep Blue ◽  
Wide Range ◽  
Cyano Groups ◽  
High Yields

Aiming to design blue fluorescent emitters with high photoluminescence quantum yields in solid-state, nitrogen-containing heteroaromatic 9,9-dimethylacridine was refined by tetraphenylethene and triphenylethene. Six tetra-/triphenylethene-substituted 9,9-dimethylacridines were synthesized by the Buchwald-Hartwig method with relatively high yields. Showing effects of substitution patterns, all emitters demonstrated high fluorescence quantum yields of 26–53% in non-doped films and 52–88% in doped films due to the aggregation induced/enhanced emission (AIE/AIEE) phenomena. In solid-state, the emitters emitted blue (451–481 nm) without doping and deep-blue (438–445 nm) with doping while greenish-yellow emission was detected for two compounds with additionally attached cyano-groups. The ionization potentials of the derivatives were found to be in the relatively wide range of 5.43–5.81 eV since cyano-groups were used in their design. Possible applications of the emitters were demonstrated in non-doped and doped organic light-emitting diodes with up to 2.3 % external quantum efficiencies for simple fluorescent devices. In the best case, deep-blue electroluminescence with chromaticity coordinates of (0.16, 0.10) was close to blue color standard (0.14, 0.08) of the National Television System Committee.

Solid State Structure and Photoluminescence properties of poly(2,5-dialkoxy-p-phenyleneethynylene)s

1995 ◽  
Vol 413 ◽  
Author(s):  
Christoph Weder ◽  
Michael J. Wagner ◽  
Mark S. Wrighton
Keyword(s):  
Solid State ◽  
Long Range ◽  
Photophysical Properties ◽  
Significant Degree ◽  
Range Order ◽  
Quantum Yields ◽  
Side Chains ◽  
Long Range Order ◽  
Rigid Rod ◽  
Covalently Linked

ABSTRACTIn an effort to better understand the relationship between molecular structure and photophysical properties, we have prepared and investigated a series of novel poly(2,5-dialkoxy-p-phenyleneethynylene)s. Wide angle X-ray diffraction measurements show that the supramolecular structure can be easily and significantly influenced by the nature of substituents covalently linked to the rigid-rod polymer main chains. Polymers which have sterically hindered side chains are essentially amorphous, while those with only linear side chains can form lamellar structures with a significant degree of long-range order. High photoluminescence quantum yields, up to 0.86 in solution and 0.36 in the solid state, have been measured. While the solution quantum yields are independent of the functionalization, solid state quantum efficiencies were found to be related to the degree of long-range order in the samples. In samples with a high degree of long-range order, the close proximity of the coplanar oriented polymer backbones is assumed to lead to the formation of eximer complexes which provide non emissive decay channels and, hence, result in comparable low photoluminescence quantum yields. In samples that adopt only a small extent of long-range order, the rigid-rod conjugated polymer backbones behave as if they were ‘dissolved’ in a hydrocarbon solvent and consequently high quantum efficiencies are obtained. Preliminary results indicate the suitability of these polymers as the emitting layer in electroluminescent devices.

Aggregation induced emission – emissive stannoles in the solid state

2020 ◽  
Vol 56 (68) ◽  
pp. 9775-9778 ◽  
Author(s):  
Isabel-Maria Ramirez y Medina ◽  
Markus Rohdenburg ◽  
Enno Lork ◽  
Anne Staubitz
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Crystalline State ◽  
Quantum Yields ◽  
Aggregation Induced Emission ◽  
First Time ◽  
Film State

For the first time, six classical stannoles with photoluminescence quantum yields of up to 11.1% in the crystalline state and 24.4% in the thin film state are presented.

scholarly journals The Role of Percent Volume Buried in the Characterization of Copper(I) Complexes for Lighting Purposes

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2647 ◽  
Author(s):  
Murat Alkan-Zambada ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Quantum Yields ◽  
X Ray ◽  
Photophysical Behavior

The usefulness of percent volume buried (%Vbur) as a readily quantifiable property is investigated with regard to [Cu(NN)(PP)]+ complexes of interest for lighting purposes. Photoluminescence quantum yields (PLQYs) and single crystal X-ray structures of 100 reported compounds were assembled, %Vbur of the ligand systems were calculated and analyzed for correlations. We found that increased shielding of the central Cu(I) cation relying on shared contributions of both (NN) and (PP) ligand systems led to increased PLQYs. These findings are of relevance for future characterizations of Cu(I)-based complexes and their photophysical behavior in the solid-state.

scholarly journals Photochemical Chain Reactions in Amorphous Solids

1988 ◽  
Vol 9 (1-3) ◽  
pp. 155-170 ◽  
Author(s):  
Arthur J. Sedlacek ◽  
Charles A. Wight
Keyword(s):  
Solid State ◽  
Spray Deposition ◽  
Product Yield ◽  
Amorphous Solids ◽  
Quantum Yields ◽  
Intermediate Step ◽  
Radical Chain ◽  
Chain Reactions ◽  
Recombination Processes ◽  
The Subject

In this article, we review recent work in the authors' laboratory on the subject of free radical chain reactions of chlorine with small hydrocarbons in amorphous solids. The solids are formed as thin films by spray deposition of the gaseous reagents onto a cryogenic window. Reactions are initiated by excimer laser photolysis at 308 nm, which dissociates a small fraction of the chlorine molecules to atoms. Product yields and branching ratios are determined by infrared absorption spectroscopy. Reactions of chlorine with cyclopropane or cyclobutane proceed by true chain reactions, as evidenced by high product quantum yields (number of product molecules formed per laser photon absorbed by the sample). Measurements of the dependence of the product yield on the relative concentrations of chlorine and hydrocarbon provide clues to the reaction mechanism in the solid state. The cyclobutane reaction appears to involve H atom transfer from cyclobutane to cyclobutyl radical as an intermediate step in the overall reaction. Reaction of chlorine with propane, n-butane, or isobutane does not appear to involve chain propagation and is dominated by radical recombination processes which result in low quantum yields. All of these results are discussed in terms of reactions which occur in a solid state environment where molecular motion is severely restricted.

LED Lumen Degradation and Remaining Life Under Exposure to Temperature and Humidity

2013 ◽  
Author(s):  
Pradeep Lall ◽  
Hao Zhang
Keyword(s):  
Solid State ◽  
Particle Filter ◽  
Luminous Flux ◽  
Remaining Useful Life ◽  
Integrating Sphere ◽  
Harsh Environment ◽  
Forward Voltage ◽  
Acceptable Error ◽  
Forward Current ◽  
Useful Life

The development of light-emitting diode (LED) technology has resulted in widespread solid state lighting use in consumer and industrial applications. Previous researchers have shown that LEDs from the same manufacturer and operating under same use-condition may have significantly different degradation behavior. Applications of LEDs to safety critical and harsh environment applications necessitate the characterization of failure mechanisms and modes. This paper focuses on a prognostic health management (PHM) method based on the measurement of forward voltage and forward current of bare LED under harsh environment. In this paper experiments have been done on single LEDs subjected to combined temperature-humidity environment of 85°C, 85% relative humidity. Pulse width modulation (PWM) control method has been employed to drive the bare LED in order to reduce the heat effect caused by forward current and high frequency (300Hz). A data acquisition system has been used to measure the peak forward voltage and forward current. Test to failure (luminous flux drops to 70 percent) data has been measured to study the effects of high temperature and humid environment loadings on the bare LEDs. A solid state cooling method with a peltier cooler has been used to control the temperature of the LED in the integrating sphere when taking the measurement of luminous flux. The shift of forward voltage forward current curve and lumen degradation has been recorded to help build the failure model and predict the remaining useful life. Particle filter has been employed to assess the remaining useful life (RUL) of the bare LED. Model predictions of RUL have been correlated with experimental data. Results show that prediction of remaining useful life of LEDs, made by the particle filter model works with acceptable error-bounds. The presented method can be employed to predict the failure of LED caused by thermal and humid stresses.

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