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Molecular glasses

Amorphous, film-forming photoconductive and charge transporting materials are addressed as molecular glasses P [Pg.5]

For many years, it was believed that polymers, but not low-molecular-weight compounds might exhibit vitrification.  [Pg.5]

Amorphous organic materials are divided into two categories compounds with low molecular weights, and polymers. Devices made from low-molecular-weight compounds are generally fabricated by vacuum deposition. Devices made from polymers are fabricated by the casting or spin-coating methods. [Pg.5]

Triarylamine and carbazole-based low-molar-mass compounds and polymers have been extensively studied for the different applications due to their good hole transport and luminescent properties.  [Pg.5]


NFS spectra of the molecular glass former ferrocene/dibutylphthalate (FC/DBP) recorded at 170 and 202 K are shown in Fig. 9.12a [31]. It is clear that the pattern of the dynamical beats changes drastically within this relatively narrow temperature range. The analysis of these and other NFS spectra between 100 and 200 K provides/factors, the temperature dependence of which is shown in Fig. 9.12b [31]. Up to about 150 K,/(T) follows the high-temperature approximation of the Debye model (straight line within the log scale in Fig. 9.12b), yielding a Debye tempera-ture 6x) = 41 K. For higher temperatures, a square-root term / v/(r, - T)/T,... [Pg.490]

In summary, the NFS investigation of FC/DBP reveals three temperature ranges in which the detector molecule FC exhibits different relaxation behavior. Up to 150 K, it follows harmonic Debye relaxation ( exp(—t/x) ). Such a distribution of relaxation times is characteristic of the glassy state. The broader the distribution of relaxation times x, the smaller will be. In the present case, takes values close to 0.5 [31] which is typical of polymers and many molecular glasses. Above the glass-to-liquid transition at = 202 K, the msd of iron becomes so large that the/factor drops practically to zero. [Pg.491]

Fig. 9.32 (a) Time evolution of the SRPAC signal (in log scale) for several temperatures obtained from the molecular glass former DBP doped with Fe-enriched ferrocene, (b) The relaxation rate X (in log scale) as a function of inverse temperature 1,000 obtained from analyzing the SRPAC... [Pg.515]

Monodisperse analogs of such ir-electron systems, PPV oligomers (molecular glasses) were studied by Bazan and coworkers [217]. The films prepared from 192 by solution casting showed completely amorphous structure due to a tetrahedral structure of the molecule and OLEDs ITO/PVK/192/Al-emitted green light with an efficiency up to 0.22 cd/A (Chart 2.42). [Pg.97]

L. Chan, H. Yeh, and C. Chen, Blue light-emitting devices based on molecular glass materials of tetraphenylsilane compounds, Adv. Mater., 13 1637-1641 (2001). [Pg.407]

FUNCTIONAL MOLECULAR GLASSES BUILDING BLOCKS FOR FUTURE OPTOELECTRONICS... [Pg.94]

VII. From Light to Current Application of Molecular Glasses in Solar Cells... [Pg.95]

Figure 3.2. Differential calorimetric curves for the molecular glasses (a) Spiro-sexiphenyl (second heating curve) and (b) Spiro-PBD (first and second heating curve). The glass transition is indicated by a characteristic step, the melting point by an endothermic peak. In (a) recrystallization occurs above Tg, which can be seen by an exothermic peak. The material in (b) forms a stable amorphous glass without recrystallization. The melting point from the first heating curve of a crystalline sample (dotted line) disappears in the second heating cycle (solid line). Only the glass transition is visible. Figure 3.2. Differential calorimetric curves for the molecular glasses (a) Spiro-sexiphenyl (second heating curve) and (b) Spiro-PBD (first and second heating curve). The glass transition is indicated by a characteristic step, the melting point by an endothermic peak. In (a) recrystallization occurs above Tg, which can be seen by an exothermic peak. The material in (b) forms a stable amorphous glass without recrystallization. The melting point from the first heating curve of a crystalline sample (dotted line) disappears in the second heating cycle (solid line). Only the glass transition is visible.
It would be an advantage to have a detailed understanding of the glass transition in order to get an idea of the structural and dynamic features that are important for photophysical deactivation pathways or solid-state photochemical reactions in molecular glasses. Unfortunately, the formation of a glass is one of the least understood problems in solid-state science. At least three different theories have been developed for a description of the glass transition that we can sketch only briefly in this context the free volume theory, a thermodynamic approach, and the mode coupling theory. [Pg.100]

Direct linkage of aromatic halves by a biphenyl bond is also possible, which leads to a large family of molecular glasses. The twist angle of this linkage is 30°, which couples the halves electronically. However, the extent of this coupling depends on the nature of the chromophore halves. Most compounds of this family are based on the common diaminobiphenyl core (Fig. 3.7). The classical... [Pg.106]

Figure 3.7. The compound TPD and related molecular glasses based on diaminobiphenyl. Figure 3.7. The compound TPD and related molecular glasses based on diaminobiphenyl.
Figure 3.8. Symmetric molecular glasses consisting of thiophenes, oxadiazoles, and perfluorinated aryl rings. Figure 3.8. Symmetric molecular glasses consisting of thiophenes, oxadiazoles, and perfluorinated aryl rings.
Figure 3.10. Molecular glasses based on a triarylamine core. Figure 3.10. Molecular glasses based on a triarylamine core.
Other structural motifs for designing molecular glasses have been exploited (Fig. 3.16). Some of them are based on five-membered rings as the central part of the molecule, like 1,2,4-triazoles (48) [94] or the electron-transporting material NAPOXA (49) [95]. Pentaphenylcyclopentane (50) exhibits a Tg of 57°C [27]. Braun et al. [96] synthesized some fulvenes with Tg ranging from 74 to 120°C (51). [Pg.120]

Other structural concepts evolved, one of them being triptycenes (55). Here, additional wings are introduced into the molecules by Diels-Alder type reactions. The glass-forming properties are improved by the propeller-like rigid structure [89]. We end our overview of the different classes of molecular glasses with these materials and note that the number of published structures is growing every year. More details on the different materials can be found in one of the recent chemical reviews [102-104]. [Pg.122]


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See also in sourсe #XX -- [ Pg.5 ]

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See also in sourсe #XX -- [ Pg.83 ]




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Absorption properties, molecular glasses

Absorption properties, molecular glasses fluorescent emitters, blue to red

Absorption properties, molecular glasses polarized light creation

Absorption properties, molecular glasses white light creation

Alq3 charge transport of molecular glasses, electron

Alq3 color conversion, molecular glasses, yellow

Alq3 molecular glass structure, chelate complexes

Alq3 molecular glasses, fluorescence quantum

Amorphous molecular glasses

Amorphous molecular glasses categories

Amorphous molecular glasses description

Amplified spontaneous emission molecular glasses

Arrhenius behavior molecular glass structure

Arylamines charge transport of molecular glasses, hole

Arylamines molecular glasses, fluorescence quantum

Azo dyes molecular glass structure, free volume theory

Azo dyes photochromic properties, molecular glasses

Challenges in Molecular Dynamics Simulations of Multicomponent Oxide Glasses

Charge transport, molecular glasses

Chelate complexes, molecular glass structure

DCM color conversion, molecular glasses

Dihydropyridines, molecular glasses

Doped systems, molecular glasses, color

Doped systems, molecular glasses, color yellow/red dopants

Effects of molecular weight on glass

Effects of molecular weight on glass transition temperature

Electron injection charge transport of molecular glasses

Emission properties, molecular glasses

Emission properties, molecular glasses fluorescent emitters, blue to red

Emission properties, molecular glasses polarized light creation

Emission properties, molecular glasses white light creation

Fluorescence quantum yield molecular glasses

Forster energy transfer molecular glasses, absorption and emission

Free volume theory, molecular glass structure

Glass rubber molecular motion

Glass structures molecular dynamics simulations

Glass transition (molecular

Glass transition molecular weight dependence

Glass transition relationships with molecular structure

Glass transition temperature and molecular weight

Glass transition temperature molecular architecture

Glass transition temperature molecular reorientation dynamics

Glass transition temperature molecular reorientation mechanism

Glass transition temperature molecular structure

Glass transition temperature molecular weight

Glass transition temperature molecular weight influence

Glass transition temperature, effect molecular weight

Glass transition theory molecular factors

Glasses, molecular, azobenzene-containing

Glassy liquid crystals amorphous molecular glasses

Heterojunction solar cells, molecular glasses

Hole injection charge transport of molecular glasses

Internal photon-to-electron-conversion efficiency , molecular glasses

Lanthanide complexes, phosphorescent emission, molecular glasses

Lasing techniques, molecular glasses laser resonators

Lithographic resist materials, molecular glasses

Merocyanines molecular glasses

Merocyanines molecular glasses, optoelectronic

Mode coupling theory, molecular glass structure

Molecular Cooperativity in the Glass Transition

Molecular cooperativity (glass

Molecular cooperativity (glass transition

Molecular dynamics glass transition

Molecular dynamics glass-forming liquids

Molecular dynamics glass-forming systems

Molecular dynamics simulation glass transition

Molecular dynamics structural glasses

Molecular glasses azobenzene-based

Molecular glasses experimental findings

Molecular glasses glass transition phenomenon

Molecular glasses glass transition regime

Molecular glasses theoretical approaches

Molecular glasses, optoelectronic applications

Molecular glasses, optoelectronic applications amplified spontaneous emission and lasing

Molecular glasses, optoelectronic applications chelate complexes

Molecular glasses, optoelectronic applications dye-sensitized solar cells

Molecular glasses, optoelectronic applications electrical excitation, multilayer organic

Molecular glasses, optoelectronic applications fluorescent emitters, blue to red

Molecular glasses, optoelectronic applications heterojunction solar cells

Molecular glasses, optoelectronic applications laser resonators

Molecular glasses, optoelectronic applications photorefractive materials

Molecular glasses, optoelectronic applications polarized light creation

Molecular glasses, optoelectronic applications properties

Molecular glasses, optoelectronic applications redox potential and charge injection

Molecular glasses, optoelectronic applications research background

Molecular glasses, optoelectronic applications starburst molecules, C3 symmetry

Molecular glasses, optoelectronic applications white light creation

Molecular weight distribution glass transition temperature

Molecular weight, glass transition temperature varying with

Morphological stability, molecular glasses

Neat molecular glasses

Number-average molecular weight, glass

Number-average molecular weight, glass transition temperature

Optoelectronics, molecular glasses

Optoelectronics, molecular glasses absorption and emission properties

Optoelectronics, molecular glasses amplified spontaneous emission and lasing

Optoelectronics, molecular glasses azo reorientation and surface gratings

Optoelectronics, molecular glasses chelate complexes

Optoelectronics, molecular glasses dye-sensitized solar cells

Optoelectronics, molecular glasses electrical excitation, multilayer organic

Optoelectronics, molecular glasses heterojunction solar cells

Optoelectronics, molecular glasses laser resonators

Optoelectronics, molecular glasses polarized light creation

Optoelectronics, molecular glasses properties

Optoelectronics, molecular glasses redox potential and charge injection

Optoelectronics, molecular glasses research background

Optoelectronics, molecular glasses solar cell light to current applications

Optoelectronics, molecular glasses starburst molecules, C3 symmetry

Optoelectronics, molecular glasses white light creation

Ordering parameter, molecular glasses

Organic light emitting diode molecular glasses

Oxadiazoles charge transport of molecular glasses, electron

Oxadiazoles molecular glass structure, twin molecules

Photochromic materials, molecular glasses

Photochromic materials, molecular glasses azo reorientation and surface gratings

Photoconductivity, molecular glasses

Photoinduced birefringence, molecular glasses

Photoinduced birefringence, molecular glasses Photonic funnels,” spiro molecules

Photoinduced birefringence, molecular glasses reorientation and surface gratings

Photorefractive materials, molecular glasses

Platinum complexes, phosphorescent emission w-heterojunction devices, molecular glasses

Polarized light, molecular glasses, absorption

Ring structures molecular glasses

Ruthenium dyes, molecular glasses, light cells

Secondary relaxation process, molecular glasses

Silicate glass molecular orbitals

Solar cells, molecular glasses, light to current

Solar cells, molecular glasses, light to current applications

Spectral overlap molecular glasses, optoelectronic

Starburst molecules charge transport of molecular glasses, hole

Structural Insight into Transition Metal Oxide Containing Glasses by Molecular Dynamic Simulations

Structural relaxation time molecular glass-forming liquids, temperature

TNF , molecular glasses, optoelectronic applications

TPD complexes charge transport of molecular glasses, hole

Thermodynamics molecular glass structure

Thiophene compounds molecular glasses, fluorescence quantum

Titanium oxide compounds, molecular glasses light to current applications, dyesensitized solar cells

Twin molecules molecular glass structure

Viscosity, molecular glass structure

Vitrification of liquids molecular glass-formers

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