Organic Thin-Film Transistors, Sensors and Printed Electronic Components
Organic Thin-Film Transistors
![]()
Thin-film transistors are a type of electronic device
which can modulate the current flowing through one part of the device by varying
a voltage elsewhere. In fabricating organic thin-film transistors (OTFTs), we
replace conventional metallic and inorganic materials with organic alternatives,
most of which are in common with the organic photovoltaic devices (OPVs)
fabricated in the Centre. The particular types of OTFT fabricated here at the COE
have the advantage of operating at low voltages. Recent research at the COE relating
to OTFTs focussed on improving the ability of the devices to modulate current
by the addition of ions to their polymer dielectric layers. This has already been
successfully demonstrated and is the subject of ongoing work.
Sensors
Owing to their low operating voltage, the types of
organic transistors discussed above are ideal candidates for being modified to
become sensors. Sensors often require detection of small changes in a given
parameter to result in a large, easy-to-measure change in an electrical output
signal. Enzymes which selectively target a specific molecule and liberate ions
electrochemically are well suited to be the recognition element in a sensor, due
to the sensitivity of the electrical characteristics of the transistors to the
number of ions within them. At the COE, we have demonstrated OTFT-based sensors
employing glucose oxidase to detect glucose.
Printed Electronic
Components
![]()
Taking advantage of the high "processability" of organic electronic
materials is important to maximise their benefits when compared with conventional
inorganics. The use of additive printing techniques (which both minimise
wastage and offer a high degree of control over material deposition) to
manufacture organic electronics is a major area of interest to the COE. As well
as aiming to print OTFTs, this research aims to enable the fabrication of discrete
passive components such as resistors and capacitors, as well as the high-conductivity
tracks required for their interconnection.
