Solution-processible thiophene/phenylene -based oligomer derivatives with different end substituents are presented as p-type
semiconducting materials in OFETs. These films were deposited on OTS-treated SiO<sub>2</sub>/Si or polymeric
bivinyltetramethyldisiloxane-bis(benzocyclobutene) (BCB)/ITO/quartz substrates, via drop-casting and spin-casting.
Synchrotron-based grazing-incidence X-ray diffraction and atomic force microscopy reveals that both drop- and spin-cast
films have highly crystalline structures with edge-on molecules and parallel π-π stacking conjugated planes with
respect to the substrate. In particular, temperature-dependent solubility of these materials can give a strategy for highly
ordered crystalline structure in spin-cast films grown on cooler substrates, when compared to warmed solutions. Field-effect
mobilities of these spin-cast films in a top-contacted electrode OFETs with BCB dielectrics are reached as high as
This paper reports on the use of new DNA-based biopolymers as the semiconducting layer in field effect transistors. Thin-film field effect transistor (FET) structures are fabricated with two different DNA-biopolymers as semiconductor layers, and two different field effect transistor structures are studied. Current voltage characteristics of the FETs show that the devices are operating in depletion mode.
Organic field-effect transistors (OFETs) currently utilize organic semiconductor materials with low electron
mobilities and organic gate oxide materials with low dielectric constants. Compared to inorganic FETs, OFETs have
slow operating speeds and high operating voltages. In this paper we discuss blending the conductive polymer
polyethylene dioxythiophene (PEDOT) with deoxyribonucleic acid (DNA), with minimal optimization to produce a
new bio-conductive polymer complex potentially suitable for OFETs. The conductivity of this new bio-conductive
polymer complex is tunable, ranging from 10<sup>-10 </sup>S/cm to 10<sup>-3</sup> S/cm at room temperature.
Photo-induced phenomena were investigated in photoresposive organic field-effect transistors (photOFETs) based on conjugated polymer/fullerene solid-state mixtures as active semiconductor layer and divinyltetramethyldisiloxane-bis(benzocyclobutene) (BCB) as gate dielectrics. The devices were characterized both in under dark showing n-type transistor behaviour with linear and saturated mobility of 1.7 x 10<sup>-3</sup> cm<sup>2</sup>/Vs and 2.7 x 10<sup>-2</sup> cm<sup>2</sup>/Vs respectively, and under white light illumination condition, where large shifts in the threshold voltage in the transfer characteristics were obtained. A typical phototransistor behaviour in a wide range of illumination intensities are observed in these devices.
Suitable organic and polymeric based materials for electronic and photonic applications must possess the desired
electromagnetic and optical properties to achieve optimal device performance in order to be more competitive with their
inorganic counterparts. A new class of biopolymer, processed from purified marine-based deoxyribonucleic acid
(DNA), has been investigated for use in both electronic and photonic applications and has demonstrated promise as an
excellent dielectric and optical waveguide material. In this paper we present examples of devices using this new DNA-based