Raman images of carriers (positive polarons) at the channel of an ionic liquid-gated transistor (ILGT) fabricated with regioregular poly(3-hexylthiophene) (P3HT) have been measured with excitation at 785 nm. The observed spectra indicate that carriers generated are positive polarons. The intensities of the 1415 cm−1 band attributed to polarons in the P3HT channel were plotted as Raman images; they showed the carrier density distribution. When the source–drain voltage VD is lower than the source–gate voltage VG (linear region), the carrier density was uniform. When VD is nearly equal to VG (saturation region), a negative carrier density gradient from the source electrode towards the drain electrode was observed. This carrier density distribution is associated with the observed current–voltage characteristics, which is not consistent with the “pinch-off” theory of inorganic semiconductor transistors.
|ジャーナル||Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy|
|出版ステータス||Published - 2018 5月 15|
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