Compact modeling of organic transistors with multi-finger contacts

Organic thin-film transistors (OTFTs) with multi-finger contacts based on dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thio-phene (DNTT) exhibit near-zero turn-on voltage, hysteresis-free behavior, and high transconductance of 30-80 μA at VDS = VGS = −2 V. [1] In addition, common-source amplifiers based on such transistors deliver voltage gain even when the supply voltage is limited to 5 V, making them attractive for flexible/wearable analog sensors. This paper presents the results of compact modeling, implemented in Matlab Simulink, applied to such transistors. The measured transistor transfer characteristics are used to extract the parameters for the semi-empirical model. The model was validated in 3 ways on 8 OTFTs with varied geometries and substrates (glass or PEN). The validation included calculations of (a) transistor output characteristics, (b) a.c. drain currents for 1 Hz sinusoidal gate voltages, and (c) output voltages of the common-source amplifier, and their comparison to the measured data