Crystallinity Engineering Induced High‐Sensitive Thermal Response in Polyvinylidene Fluoride by x‐Ray Irradiation

Polyvinylidene fluoride (PVDF) and its copolymers have garnered significant interest for flexible and wearable sensors. However, the sensitivity of PVDF‐based sensors is limited by their relatively low pyroelectric properties compared to those of inorganic ferroelectric materials. In this study, we report on poly(vinylidene fluoride‐co‐trifluoroethylene) (P(VDF‐TrFE)) films exposed to x‐ray irradiation to increase the crystallinity and β‐phase content. This increase in crystallinity and β‐phase content ultimately improved the pyroelectric coefficient (150.9 μC m −2 K −1 ) by almost more than five times. The sensors, based on the irradiated P(VDF‐TrFE) films, showed an outstanding thermal voltage sensitivity of 15.07 V K −1 and a current sensitivity of 12.19 nA K −1 . The sensors exhibited excellent linear temperature sensing and a precision infrared detector, making them promising candidates for self‐powered electronic skin in human‐machine interaction applications.