The fabrication and characterization of poly(4-vinylpyridine)-based thin film transistors exhibiting enhanced ion modulation

Lithium perchlorate-doped hygroscopic poly(4-vinylpyridine)-based organic thin film transistors have been fabricated and characterized. More than one mechanism of current modulation is observed in these devices with the observed mechanism depending upon both the amount of added dopant and the operating voltage. At low gate voltages (0 to −0.8 V) the current modulation mechanism is dominated by ions intrinsic to the dielectric layer (due to its hygroscopic nature), while at higher gate voltages (−1 to −2 V) the device behavior is governed by the movement of the dopant ions. Most importantly, through careful control of dopant concentration, we show that it is now possible to fabricate all-solution processed devices with significantly enhanced current modulation. In particular, we demonstrate that current modulation ratios in excess of 105 are possible with this device architecture.

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► Proton acceptor hygroscopic poly(4-vinylpyridine) for organic thin film transistor.
► Two current modulation mechanisms depending upon the operation voltages.
► Two current modulation mechanism operating in different time scales.
► Improved current modulation at an optimal added ion concentration.