Temperature-Dependent Current–Voltage and Photoresponsive Properties for Semiconducting Nanodevices Fabricated from an Oligothiazole Dithiol and Gold Nanoparticles

A rigid
oligothiazole dithiol molecule (3) is first introduced
to fabricate the self-assembled granular thin films with gold nanoparticles
(Au-NPs) covering 1 μm gap gold electrodes by means of the Au–S
bonded contacts, where the nanocomposite thin films prepared from
different concentrations of dithiol 3 and Au-NPs (1.0,
0.5, and 0.1 mmol/L) exhibit temperature-dependent semiconducting I–V behavior in the order of μA,
nA, and pA and photoresponsive properties in the temperature range
8–300 K. Compared with the nanodevices fabricated from similar
oligothiophene dithiols, it is interesting to mention that the oligothiazole
dithiol based ones show analogous morphologies and temperature-dependent I–V characteristics but enhanced
photoresponsvie properties, which may arise from the improved charge
separation ability of oligothiazole in stabilizing the photogenerated
electron carriers. To the best of our knowledge, this is the first
report in which an oligothiazole dithiol molecule acts as a bridging
unit to link Au-NPs exhibiting photoresponse properties in the solid
state.