Charge Transport in Organic Semiconductors

Abstract

refs.]. -(COROPCEANU, V.; CORNIL, J.; DA SILVA FILHO, D. A.; OLIVIER, Y.; SILBEY, R.; BREDAS*, J.-L.; Chem. Rev. (Washington, D. C.) 107 (2007) 4, 926-952; Ga. Inst. Technol., Sch. Chem. Biochem., Atlanta, GA 30332, USA; Eng.) -Lindner 29-266

Optoelectronic and Semiconducting Properties of Conjugated Polymers Composed of Thiazolo[5,4-d]thiazole and Arene Imides Linked by Ethynylene Bridges

“…4,22,33 For two perfectly stacked molecules, it is known that small molecular displacements may also lead to significant changes in the t 12 value. 45 Figure 7 shows indeed strong oscillations in the value of t 12 for displacements of polymer chains I and V along the x-and y-axes in dimers consisting of two π-stacked infinite chains.…”

“…In organic crystals, the outer reorganization energy is in the order of few tenths of an electronvolt or lower, contrary to charge transfer in solution wherein the external part dominates. 3,[42][43][44][45] Different values for λ s , ranging between 0.01 and 0.2 eV, have been proposed and employed in literature. [46][47][48][49] As in previous works, λ s was fixed at 0.1 eV in order to facilitate the comparison with previous rate constants reported for PAEs.…”

“…3,45,52,53 Since the inner reorganization energy controls the charge-phonon 8 coupling, if λ 1 ≈ λ 2 , we can write λ i ≈ 2λ 1 , and this condition can be satisfied when the molecular structure is not largely deformed during the ionization process. 54 The charge hopping transport is favored by a small polaron binding energy (E pol ), defined as the relaxation energy of an ionized molecule.…”

“…34,35,52 In the case of symmetrically arranged polymers, e 1 = e 2 as the infinite chains can be considered as equivalent molecules in the crystal and equation (6) and (7) can be written as. 3,34,45,52 ‫ݐ|‬ ଵଶ ି | = ா ಽశభ ିா ಽ ଶ (8)…”

4-Terminal Tandem Photovoltaic Cell Using Two Layers of PTB7:PC71BM for Optimal Light Absorption

“…17 Many different factors including molecular packing, disorder or low crystallinity, presence of impurities, temperature, electric field, charge-carrier density, size/molecular weight and pressure can degrade such mobility. 18 The detrimental effects become more apparent for thicker blends by causing a dramatic reduction in fill factor (FF) for the majority of polymers. 19 Recent work explains that for sufficiently thick cells space charge becomes more important because it creates field free regions with low collection efficiency.…”