Signal amplification with patterned conducting polymer electrodes based organic thin film transistor circuit

Abstract

Organic thin film transistors (OTFTs) fabricated with non-destructive patterning techniques are the building blocks in realizing flexible electronic interface for sensing applications. In this study, a single stage differential amplifier is demonstrated with flexible OTFTs. The OTFTs were fabricated with thermally evaporated Pentacene as the semiconducting layer. The electrodes of the OTFTs were realized using a conductive polymer composite, poyaniline:polystyrene sulphonic acid (PANi-PSS), patterned by a modified Parylene lift-off process. Electrical characteristics of bottom contact TFTs with polymeric PANi-PSS electrodes is superior to those with conventional metal electrodes due to a lower charge injection barrier and resultant lower contact resistance. The measurement of the transistor characteristics and the amplifier response reported has been carried out with a wafer probing test jig set up. The differential amplifier realized with p-type Pentacene transistors with mobility, 0.5 cm 2 /Vs, exhibited a voltage gain of 10 dB in a frequency bandwidth of 1 kHz.

Recent progress in organic field‐effect transistor‐based integrated circuits

“…Nair et al fabricated a flexible differential amplifier using a 3 00 -sized polyethylene naphthalate (PEN) substrate. 94 The semiconducting layer is thermally evaporated pentacene while the contact electrodes are made of a solution processable conducting polymer maned poyaniline:polystyrene sulphonic acid (PANi-PSS) with a novel lift-off patterning method. The amplifier shows a gain of 10 dB in a maximum frequency of 1 kHz.…”