Absorption and Emission in Quaterthienyl Thin Films

Abstract

The salient features in the absorption and emission spectra of αT4 aggregates (see Figure) and films are fully accounted for using a model based on linear exciton–phonon coupling and structural defects. In particular, the Davydov splitting is calculated to be of the order of 1 eV, and the unusually small 0–0 emission intensity is attributed to the high sensitivity of the 0–0 intensity to basal plane structural defects.

Exciton-phonon coupling in molecular crystals: Synergy between two intramolecular vibrational modes in quaterthiophene single crystals

“…12 Quaterthiophene is a widely studied molecular material [11][12][13][14][15][16][17][18][19][20][21] which possesses interesting properties for both applications and fundamental research, 22 since it can be regarded as a model system for many molecular materials crystallizing in a herringbone packing arrangement such as oligothiophenes 15,23 and p-oligophenylene vinylenes. 24,25 The crystallographic structure of the low-temperature 4T polymorph is monoclinic with four molecules per unit cell, whose axes are a = 6.09 Å, b = 7.86 Å, and c = 30.48 Å, the angle ␤ between a and c being 91.8°.…”

Dielectric tensor and optical spectra of quaterthiophene crystals

“…In particular, oligothiophenes (nT) are widely studied and many efforts have been devoted to understand their solid-state properties as representative of a large class of materials that possess strong optical transitions [1,2]. Despite many theoretical and experiment approaches reported in the literature [3][4][5][6][7][8][9][10], there is not a generally accepted value to date for the factor group splitting. Recently, we have been able to synthetize highly pure 4T and to grow high-quality single crystals with different size and thickness [11].…”

Thin Film Phase and Local Chirality of Surface-Bound MOP4 Nanofibers

“…The projection of the local molecule orientation onto the substrate surface at this position is estimated by the polarization angle: the transition dipole between the first 4 excited singlet state S 1 and the electronic ground state S 0 , which results in fluorescence in the visible and UV-spectral range, is supposedly along the long molecular axis 17,[41][42][43] . The relation between polarization angle and local fiber orientation θ orient (x, y) [44][45][46] (mapped to the range from 0 • to 180 • ) is determined by…”