To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Photoactive organic field-effect transistors, photOFETs, based on a conjugated polymer/fullerene blend, MDMO-PPV: PCBM (1:4), and polymeric dielectrics as polyvinylalcohol (PVA) or divinyltetramethyldisiloxane-bis(benzocyclobutene) (BCB) with top source and drain electrodes were fabricated and characterized in dark and under AM1.5 illumination. With LiF/Al as top source and drain contacts the devices feature n-type transistor behavior in dark with electron mobility of 10-2 cm2/Vs. Under illumination, a large free carrier concentration from photo-induced charge transfer at the polymer/fullerene bulk heterojunction (photodoping) is created. The device performance was studied with different illumination intensities and showed to be strongly influenced by the nature of the organic dielectric/organic semiconductor interface resulting in phototransistor behavior in BCB-based photOFETs and in phototransistor or photoresistor behavior for PVA-based photOFETs.
The preparation of double-cable polymers, which consist of a hole conducting conjugated chain carrying pendant electron accepting/conducting moieties, is a promising strategy to prevent donor/acceptor phase segregation and to achieve defined microscopic structure in organic bulk heterojunction solar cells. In this paper we report the electrochemical synthesis and the investigation of a double-cable consisting of a polythiophene backbone bearing, via covalent bonds, electron accepting tetracyanoanthraquinodimethane (TCAQ) type moieties. Electrochemical studies and UV- VIS absorption spectroscopy reveal, that in dark, the polythiophene chain and the TCAQ moieties retain their individual ground-state properties. Upon illumination photoinduced electron transfer occurs, which is studied by photoinduced VIS-NIR absorption spectroscopy.
Difference infrared spectra between illumination and dark of a polyethylenedioxythiophene (PEDOT) covered germanium electrode in contact with the electrolyte solution and under applied potential are shown. The spectra show a different behavior at different redox (doping) states of the polymer. The photoinduced formation of positive charge carriers was found by illumination of the neutral (undoped) form, wheras no significant spectral changes occur in the oxidized (p-doped) and reduced (n-doped) form of PEDOT.
This work focuses on single - and bilayers of para - hexaphenyl (PHP) and C60 grown by Hot Wall Epitaxy. A detailed study of the growth process was performed on glass, ITO and (001)- oriented cleaved mica substrates. The ordering of the layers was investigated by X-ray diffraction, showing clear diffraction peaks for layers grown on mica. The PHP layers grown on mica show high optical anisotropy (dichroic ratios up to 14 in emission) according to the polarization dependent photoluminescence experiments. The highly ordered structure is also reflected in the surface morphology of the layer as observed by atomic force microscopy. The epitaxial growth on mica is mirrored by the main alignment of the surface structure to the orientation of the mica substrate.
Email your librarian or administrator to recommend adding this to your organisation's collection.