Manipulation of field-effect transistors by flexoelectric effect

Abstract

Flexoelectric field-effect transistors (FE-FETs) hold significant potential for applications in biomedical and healthcare sensing fields. While existing piezoelectric FETs sense physiological signals based on pressure or compressive strain, movements such as bending of the elbow or knee joints are more common in physiological activities than external pressure. To address this, this study innovatively introduces FE-FETs that are regulated through the flexoelectric effect induced by bending. In this study, MoS2 with flexoelectric properties is utilized as the channel region. By bending the FE-FETs, the flexoelectric effect is induced, generating a flexoelectric response voltage that alters the Schottky barrier. The results confirm that varying the bending angle of the FE-FETs effectively modulates their transconductance and carrier mobility. Remarkably, the combination of traditional gate voltage and the flexoelectric effect results in a maximum carrier mobility of 49.63 cm2/V · s within a drain voltage range of 0–1 V, which is approximately 10.6 times higher than the carrier mobility of 4.68 cm2/V·s under traditional gate voltage alone. This study provides an effective approach to regulating FE-FETs and expands the possibilities for their application in wearable technology.