Oligothiophenes bearing polar groups for organic thin film transistors: synthesis, characterisation and preliminary gas sensing results

The properties of a series of sexithiophenes bearing amide or ester functionalities in the alpha,omega-positions are reported. Isolation of the ester functionalities from the sexithiophene core by an ethylene spacer led to a device with moderate hole mobilities (1.2-10
^-2
cm
²
V
^-1
s
^-1
) and on/off ratios (10
³
). A bottom contact device based on this sexithiophene showed a good response to a 5 ppm NO atmosphere, encouraging future studies on gas sensing OTFT based on these polar-functionalised OTFT.