Oligothiophenes thin films

Figure 13.24. Schematic presentation of probable decay mechanisms in oligothiophene thin films. X X-traps k, k-, fej-r - rate...

In this section the morphology of oligothiophene thin films will be reviewed. In particular the orientation of the molecules with respect to the substrate normal and the long-range order will be discussed. 

Figure 41. Schematic presentation of probable decay mechanisms in oligothiophene thin films. X X-traps k, k r, kf, kcr rate constants for radiative, non-radiative, and fluorescence decay and the transition into the charge-transfer state, respectively kT thermal energy E external or internal electric field [181],...

There are only few pubhshed results on intentionally doped oligothiophene thin films. 

The photogeneration of charged excitations in oligothiophene thin films was only studied for a-6T in which the threshold for photoexcitation of charges has been located at around 2.2 eV by a comparison of the one photon excitation curve for radiative recombination and the photoconduction action spectrum [257]. 

S.A. Lee, Y. Yoshida, M. Fukuyama, and S. Hotta, Phenyl-capped oligothiophenes novel light-emitting materials with different molecular alignments in thin films, Synth. Met., 106 39-43, 1999. 

K. Uchiyama, H. Akimichi, S. Hotta, H. Noge, and H. Sakaki, Electroluminescence from thin film of a semiconducting oligothiophene deposited in ultrahigh vacuum, Synth. Met., 63 57-59,1994. 

Other low-molecular systems that have been investigated in waveguiding films are the guest-host system Alq3 DCM (see below for the emission in tme resonators), arylamines, and oligothiophenes. TPD (6) shows an emission peak in thin films at 418 nm when pumped with 35-ps pulses at 347 nm [185]. The... 

Compositions consisting of poly(oligothiophene-thiazole), ( ), having an Af of 40,000 Da were prepared by Hanh et al. (3) and used as organic insulating films in thin-film transistors in liquid-crystal display devices. 

Quinodimethane derivatives of terthiophene and other oligomers showed an absorption maximum at 583-688 nm (02JOC6015 03OL1535). Bis(dicyanoethylene) oligothiophene derivatives have been characterized and the compound with four thienyl rings showed an absorption band at 790 nm (02JA12380). This type of compounds was used in thin film transistors (see below) (02JA4184). 

Optical absorption and fluorescence spectra of 636-655 were measured both in solution and as thin films to assess the effect of both fluoroalkyl-versus alkyl- and a,co- vs ( , ( -substitutions on oligothiophene absorption and emission maxima (Xabs/Am) and the (optical) HOMO-LUMO energy gaP-... 

Murphy AR, Frechet JMJ, Chang PC, Lee JB, Subramanian V. (2004) Organic thin film transistors from a soluble oligothiophene derivative containing thermally removable solubilizing groups. / Am Chem Soc 126 1596. 

Assembly, Structure, and Performance of an Ultra-Thin Film Organic Field-Effect Transistor (OFET) Based on Substituted Oligothiophenes... 

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