Optical properties of fully and partially fluorinated rubrene in films and solution

Anger, F.; Scholz, Reinhard; Adamski, E.; Broch, Katharina; Gerlach, Alexander; Sakamoto, Youichi; Suzuki, Toshiyasu; Schreiber, Frank

doi:10.1063/1.4773520

Cited by 22 publications

(52 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Under these conditions, PF-RUB thin films on native SiO 2 substrates are supposed to grow amorphous. 12 The concentration of the diluted solution of PF-RUB molecules in CH 2 Cl 2 was ∼2 mol/l. Raman spectra were acquired using an Horiba Jobin Yvon LabRam HR 800 spectrometer with a CCD-1024 × 256-OPEN-3S9 as detector.…”

Section: Methodsmentioning

confidence: 99%

“…45 We find that the twisted D 2 isomer is energetically favored by −0.34 eV against the planar C 2h conformation, which is roughly twice as much as in the case of RUB. 12 For better comparison of the computed model with the experimental spectra, the intensity of each mode is represented by a Lorentzian. The energy axis of the computed modes was scaled by a factor of 0.9915, which we found to yield a very good agreement between the theoretical model and experimental values for most modes.…”

Section: A Ir and Raman Spectra Of Pf-rubmentioning

confidence: 99%

“…[5][6][7] One very effective way to tune the electronic properties of a material and at the same time to mitigate the molecular reactivity with oxygen 8 is fluorination, since fluorine is the most electronegative element. [9][10][11][12][13] While the optical properties as well as the energy level alignment of perfluororubrene (C 42 F 28 , PF-RUB) have already been studied, 12,14,15 a characterization of the molecular vibrations is still lacking. The vibrational modes, however, are fundamental properties of a molecule that play an important role for the understanding of molecular charge carrier transport properties.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Vibrational modes and changing molecular conformation of perfluororubrene in thin films and solution

Anger

Scholz

Gerlach

et al. 2015

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

We investigate the vibrational properties of perfluororubrene (PF-RUB) in thin films on silicon wafers with a native oxide layer as well as on silicon wafers covered with a self-assembled monolayer and in dichloromethane solution. In comparison with computed Raman and IR spectra, we can assign the molecular modes and identify two molecular conformations with twisted and planar tetracene backbones of the molecule. Moreover, we employ Raman imaging techniques to study the morphology and distribution of the molecular conformation in PF-RUB thin films.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: A Ir and Raman Spectra Of Pf-rubmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Vibrational modes and changing molecular conformation of perfluororubrene in thin films and solution

Anger

Scholz

Gerlach

et al. 2015

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Ширина запрещенной зо-ны, определенная по краю собственного поглощения (рис. 2), составила 2.27 eV, что типично для рубрена [7].…”

Section: поступило в редакцию 8 июня 2016 гunclassified

Исследование Механизмов Токопрохождения В Тонких Пластинах Рубрена, Изготовленных Газотранспортным Методом

Таларико¹,

Трегулов²,

Литвинов³

et al. 2016

Письма В Журнал Технической Физики

View full text Add to dashboard Cite

Проведены исследования оптического спектра пропускания и температурной зависимости вольт-амперных характеристик плоскопараллельной пластины рубрена, изготовленной газотранспортным методом. Из оптического спектра пропускания определено значение ширины запрещенной зоны. Установлено, что вольт-амперные характеристики могут быть объяснены в рамках модели токов, ограниченных пространственным зарядом. На процессы токопрохождения существенное влияние оказывают ловушки.

show abstract

“…Rubrene became thus a model system to study intermolecular interactions and charge transport properties of molecular solid states 10,20,21,[25][26][27][28][29][30][31] . The outstanding charge transport properties might be related to the peculiar molecular structure of rubrene with the frontier orbitals mainly located on the tetracene backbone and the electronically inactive phenyl side groups 28,[32][33][34] . In single crystals this shape leads to structure 35 which allows overlap of molecular wave-functions 10,29 leading to band dispersion with large HOMO band widths of ~0.4 eV, which have been experimentally determined by UPS 27,36 .…”

Section: Introductionmentioning

confidence: 99%

Transient Monolayer Structure of Rubrene on Graphite: Impact on Hole–Phonon Coupling

Bussolotti

Xin

et al. 2016

J. Phys. Chem. C

View full text Add to dashboard Cite

Charge transport in molecular thin films is often dominated by incoherent hopping processes and charge-carrier phonon coupling plays a major role in defining mobilities. Our high resolution angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) study reveals the influence of molecular configuration and packing on the hole-phonon coupling in vacuum-sublimed thin films of rubrene on graphite and allows determining charge reorganization energies. In the contact layer to the substrate rubrene is well-ordered with, for low coverages, the tetracene backbone being almost parallel to the graphite surface forming a loose-packed monolayer. Increasing the coverage leads to an orientational transition and a more tilted orientation of rubrene in a close-packed monolayer. This transition results in dramatic changes of spectral features in ARUPS including the photoelectron angular distribution of the highest occupied molecular orbital derived intensity. The charge reorganization energy, however, only changes slightly. The transient monolayer structure of rubrene on graphite allows thus to demonstrate that hole-phonon coupling in organic thin films does not depend very critically on the packing structure. IntroductionLow charge-carrier mobilities are often limiting the performance of organic (opto-)electronic devices as charge transport in organic semiconductor thin films is often dominated by incoherent hopping processes 1-4 . Hopping mobilities depend critically on the charge-carrier phonon coupling 5-8 , which determines the charge reorganization energy λ. In most molecular thin films intermolecular interactions are weak and λ is consequently dominated by intramolecular vibrations and is often taken from gas-phase calculations 5,9-11 or gas-phase ultraviolet photoelectron spectroscopy (UPS) data 9,12-14 . However, the relevant quantities for device application are the solid state values, which depend on the molecular surrounding, i.e. the interaction with neighboring molecules and/or a substrate 7,15 . Due to the similarities of ionization (followed by neutralization) during localized hopping transport and photoionization, UPS is the method of choice to measure charge reorganization energies of organic thin films by an analysis of the vibrational fine structure of the highest occupied molecular orbital (HOMO)-derived peak 7,8,[15][16][17][18] . The relevant vibrational energies (hν i ) of a molecule are often centered closely and in good approximation the analysis can be done by a single mode fit with one main vibrational energy (hν) 19 . Moreover, in most molecular thin films the relaxation energies for ionization and neutralization of a molecule are rather similar and the charge reorganization energy is thus simply given by λ=2Shν with S being the Huang-Rhys factor, which is determined by the relative intensity contribution to the vibrational progressions 7,13 .

show abstract

Optical properties of fully and partially fluorinated rubrene in films and solution

Cited by 22 publications

References 31 publications

Vibrational modes and changing molecular conformation of perfluororubrene in thin films and solution

Vibrational modes and changing molecular conformation of perfluororubrene in thin films and solution

Исследование Механизмов Токопрохождения В Тонких Пластинах Рубрена, Изготовленных Газотранспортным Методом

Transient Monolayer Structure of Rubrene on Graphite: Impact on Hole–Phonon Coupling

Contact Info

Product

Resources

About