Flexible pressure sensors based on organic field‐effect transistors (OFETs) have emerged as promising candidates for electronic‐skin applications. However, it remains a challenge to achieve low operating voltages of hysteresis‐free flexible pressure sensors. Interface engineering of polymer dielectrics is a feasible strategy toward sensitive pressure sensors based on low‐voltage OFETs. Here, a novel type of solution‐processed bilayer dielectrics is developed by combining a thick polyelectrolyte layer of polyacrylic acid (PAA) with a thin poly(methyl methacrylate) (PMMA) layer. This bilayer dielectric can provide a vertical phase separation structure from hydrophilic interface to hydrophobic interface which adjoins well to organic semiconductors, leading to improved stability and remarkably reduced leakage currents. Consequently, OFETs using the PMMA/PAA dielectrics reveal greatly suppressed hysteresis and improved mobility compared to those with a pure PAA dielectric. Using the optimized PMMA/PAA dielectric, flexible OFET‐based pressure sensors that show a record high sensitivity of 56.15 kPa⁻¹ at a low operating voltage of −5 V, a fast response time of less than 20 ms, and good flexibility are further demonstrated. The salient features of high capacitance, good dielectric performance, and excellent reliability of the bilayer dielectrics promise a bright future of flexible sensors based on low‐voltage OFETs for wearable electronic applications.

中文翻译：

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用于压力传感应用中柔性低压有机场效应晶体管的溶液处理双层电介质

基于有机场效应晶体管（OFET）的柔性压力传感器已成为电子皮肤应用的有希望的候选者。然而，实现无磁滞柔性压力传感器的低工作电压仍然是一个挑战。聚合物电介质的界面工程是基于低压 OFET 的敏感压力传感器的可行策略。在这里，通过将厚的聚丙烯酸（PAA）聚电解质层与薄的聚（甲基丙烯酸甲酯）（PMMA）层相结合，开发出了一种新型的溶液加工双层电介质。这种双层电介质可以提供从亲水界面到疏水界面的垂直相分离结构，该结构与有机半导体很好地邻接，从而提高了稳定性并显着降低了漏电流。因此，与使用纯 PAA 电介质的 OFET 相比，使用 PMMA/PAA 电介质的 OFET 表现出大大抑制的磁滞现象和改进的迁移率。使用优化的 PMMA/PAA 电介质、基于 OFET 的柔性压力传感器，在 -5 V 的低工作电压下显示出创纪录的 56.15 kPa ^-1的高灵敏度、小于 20 ms 的快速响应时间以及良好的灵活性证明了。双层电介质的高电容、良好的介电性能和出色的可靠性等显着特点，为可穿戴电子应用中基于低压 OFET 的柔性传感器带来了光明的前景。