Highly stable printed polymer field-effect transistors and inverters via polyselenophene conjugated polymers

Abstract

We report the use of two polyselenophene-based conjugated polymers, poly(3,3′′-didodecyl-2,2′:5,2′′-terselenophene) (P3Se) and poly(3,3′′,3′′′,3′′′′-tetradodecyl-2,5′:2′,2′′:5′′,2′′′-pentaselenophene) (P5Se), as an active layer of printed p-channel organic field-effect transistors (OFETs). Top-gate/bottom-contact (TG/BC) P5Se OFETs showed a high-saturation hole mobility of up to ∼0.1 cm² V⁻¹ s⁻¹ and a high on/off ratio of ∼10⁵ with no hysteresis. In addition, polyselenophene-based OFETs exhibited a much better bias and ambient stability when compared with poly(3-hexylthiophene)-based OFETs. The excellent air stability of those polyselenophenes enables the realization of complementary metal-oxide semiconductor (CMOS) inverters via extended periods of ink-jetting under ambient conditions. CMOS inverters were demonstrated using p-[P5Se] and n-channel [poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-s,6-diyl]-alt-5,5′-(2,2′-dithiophene)}] ([P(NDI2OD-T2)], Polyera ActivInk N2200/OFETs) by inkjet printing of conjugated polymers. Printed CMOS inverters exhibited a stable voltage transfer characteristic with negligible hysteresis, a DC voltage gain of ∼10, and a power consumption of ∼0.025 mW at V_DD = −60 V.