How substitution tunes the electronic and transport properties of oligothiophenes, oligoselenophenes and oligotellurophenes
Küçük Resim Yok
Tarih
2015
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Sa
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The geometrical, electronic and charge-transport properties of a series of unsubstituted and dicyanovinyl (DCV)-substituted oligothiophenes (nT), oligoselenophenes (nS) and oligotellurophenes (nTe) where n = 3-5 are investigated by means of Density Functional Theory (DFT) and Time-Dependent DFT calculations. The intramolecular reorganization energy is found to decrease upon dicyanovinyl substitution, with a larger decrease for holes than electrons. The ground state HOMO and LUMO energies along with the Time-Dependent DFT calculations show smaller HOMO-LUMO gaps for the DCV-substituted oligomers. Calculations of the intermolecular charge transfer integrals in the crystals have been performed to understand the role of substitution on the charge-transport rate. DCV-substitution changes the packing motifs in the crystal and results in larger transfer integrals for holes along the pi-stacldng direction, calculated as -63 and -88 meV for DCV4T and DCV4S respectively. These results suggest that DCV-substituted oligomers studied here are more promising charge transporting materials than their unsubstituted analogues. (C) 2015 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Organic Photovoltaics, Organic Semiconductors, Donor Materials, Dft Calculations, Charge Transport, Density-Functional Thermochemistry, Generalized Gradient Approximation, Charge-Transport, Correlation-Energy, Excited-States, Hole, Polarization, Polymorphism, Parameters, Cells
Kaynak
Synthetic Metals
WoS Q Değeri
Q2
Scopus Q Değeri
Q1
Cilt
210
