Stable InSe transistors with high-field effect mobility for reliable nerve signal sensing

Among two-dimensional layered semiconductors, indium selenide (InSe) is one of the most promising materials with absolute advantages in field-effect transistors (FETs) because of its high electron mobility and stable material properties. Some work has been performed to improve the mobility of InSe FETs. However, in practical applications, electrical stability of FETs is another essential factor to guarantee the performance of the electronic system. Here, we show a highly stable InSe FET with a field-effect mobility of 1200 cm²/V·s in the practical working regime. The bottom-gate staggered InSe FET was fabricated with a polymethyl methacrylate (PMMA)/HfO₂ dual-layer gate dielectric and PMMA back-channel encapsulation. The hysteresis was maintained at 0.4 V after 30 days of storage under normal ambient conditions, and the threshold voltage shift was retained at 0.6 V with a gate stress V_GS of 10 V, which represents the best electrical stability reported to date. Its high mobility and electrical stability enable reliable detection of the weak nerve action potential at a low power consumption. High-performance InSe FETs expand their promising applications in flexible and in situ real-time intelligent nerve action potential recording.