Investigation of the sensing mechanism of dual-gate low-voltage organic transistor based pressure sensor

Abstract

Abstract Dual-gate pressure sensors consist of a piezoelectric polyvinylidene fluoride and trifluoroethylene P(VDF-TrFE) sensor and a low-voltage OFET read-out element. The pressure-induced voltage from the piezoelectric layer depletes charge carriers accumulated in the channel of the OFET, causing a shift in threshold voltage. By a quantitative analysis of results obtained from both the dual-gate organic pressure sensor and a conventional dual-gate OFET, we show that the piezoelectric constant of the sensing layer is estimated to be 72 pC/N. By comparing this value with that measured directly with piezoelectric measurement system, we concluded that the operation mechanism of the dual-gate pressure sensor was due to the piezoelectric behavior of the P(VDF-TrFE) layer.