Antisolvent polysulfone dielectric for ultrastable solution-processed high-performance conformal organic transistor array

Abstract

Conformal organic field-effect transistors (OFETs) have attracted tremendous attention for next-generation skin-like electronics due to their mechanical flexibility, low-cost, large-area fabrication, and tunable electrical performance. However, the reported commercial polymer dielectrics suffer from poor solvent resistance, and the limited available antisolvent dielectrics such as hydroxyl-containing PVA and PVP dielectrics OFETs exhibit poor electrical stability. Herein, a nonpolar polysulfone (PSU) dielectric is firstly integrated into solution-processed OFETs and serves as the dielectric layer. Compared with commonly used dielectrics such as PMMA, PS, PVA, and PVP, PSU possesses enhanced solvent stability, thermal stability, humidity stability, and capacitance stability. The solvent resistant PSU dielectric enables the solution-processed C8-BTBT OFET array to achieve on-state currents over 1 mA and ultrahigh mobility up to 10.84 cm² V⁻¹ s ⁻¹ (1 Hz). The PSU dielectric OFETs also exhibit excellent cycle stability, thermal stability, humidity stability, and bias stability. Moreover, the conformal OFETs demonstrate ultrahigh mobility (9.34 cm² V⁻¹ s⁻¹), even when adhering to the limited bending radius down to 1 μm, which is the highest mobility among the reported conformal OFETs. Even after crumpling 50 times, there is no significant decrease in electrical performance. Our results provide a novel dielectric selection for stable solution-processed organic transistors, and show the huge potential of PSU dielectrics in future wearable skin-like electronics.