Examining the Performance in Low-Power Flexible OFETs: An Energetics Perspective

Flexible electronics is the future of the consumer electronics industry. It is finding its way into consumer appliances such as TVs and smart wearable devices, along with niche applications such as biosensors. Although flexible devices in research labs are exhibiting promising performances, it tends to fall short of the performance shown by the devices fabricated on solid substrates.¹ We examine the shortcomings of the flexible organic field-effect transistors (OFETs) from an energetics point of view. OFETs with four configurations Glass(or PET)/ITO/ZrO₂(or Ta₂O₅)/PBTTT/Au are fabricated in ambient conditions using solution-processed organic semiconductor PBTTT-C14. The devices show high performance and <1V operation. The trap-density of states (trap-DOS) is calculated using Geiger’s modified Grünewald’s method.² It is observed that the lower performance in flexible devices is correlated with higher trap-DOS at the dielectric/semiconductor interface. This understanding paves a way for further improvements in flexible devices.

[1] Park, Y. M.et al. Chem. Mater. 2013, 25 (13), 2571–2579.
[2] Geiger, M. et al. Phys. Rev. Applied 2018, 10 (4), 044023.