Dopingless organic tunnel field-effect transistor: DC and RF performance analysis

Abstract

Flexible screens and e-papers need advanced devices and techniques for effective functionality. Organic thin film transistors (OTFTs), essential for these applications, face significant challenges due to short-channel effects (SCE), hindering current saturation at nano-dimensions. To address this challenge, doped organic tunnel field-effect transistors (O-TuFETs) have been suggested, although doping the organic transistors remains challenging and adds design complexity. To overcome these limitations, a novel dopingless DL O-TuFET is proposed utilizing work function engineering. A key challenge in DL tunnel transistors is ambipolarity; however, by tuning the work functions of the drain and source, as well as adjusting the drain to source voltage (V_DS) and gate length (L_G), ambipolarity can be effectively suppressed. The key performance metrics of DL O-TuFET achieve a threshold voltage (V_TH) of −2.5 V, a subthreshold swing (SS) of 155 mV/decade, a maximum ON current of 2.03 μA and an ON/OFF current ratio of approximately 10¹² with the inclusion of bulk and interface trap defects. These characteristics make the DL O-TuFET an attractive option for powering flexible display systems. A maximum cut-off frequency (f_t) of 0.04 GHz highlights its suitability for moderate-speed, flexible electronics.