Mechanically induced flexible two-dimensional PdSe2 sensors based on piezotronic effect

초록

Flexible devices with the capacity to develop adaptive and ideal interactions between machines and humans are valuable in healthcare, artificial intelligence, and the Internet of Things (IoTs). In this study, we created a flexible strain-sensitive sensor employing graphene and a two-dimensional PdSe2 thin film through chemical vapor deposition (CVD) and placed them on a PET film. Mechanically induced piezotronic effect in compressive and tensile modes was used to control the Schottky barrier height based on piezoelectric charge polarization, and therefore, to synergistically modulate the current conduction process. The piezotronic device exhibited seamless performance with a strain-gauge value of 715 at a compressive strain of -0.24 %, which is 9.48 times more than that of a typical strain-gauge value. Furthermore, at low temperatures (240 K) the device showed a larger gauge factor at an applied strain of 0.24 % owing to the decreased screening effect that underlays the increase in piezopolarization charges. Our findings provide evidence for the mechanically induced piezotronic effect in PdSe2 thin films, a significant structure that enable versatile functionalities in innovative micro- and nanoelectromechanical systems and devices.

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