Piezopotential gated two-dimensional InSe field-effect transistor for designing a pressure sensor based on piezotronic effect

Pressure sensors have been widely employed and generally consist of complex circuits or multilayered matrix structures based on piezoresistivity, capacitance, and electricity. Herein, we propose a piezoelectric pressure sensor constituted by flexible ZnO nanorod (NR) arrays and a 2D indium selenide (InSe)-based field-effect transistor (FET). The ZnO NR arrays transform stress into piezoelectric voltage, which contributes to the gate potential. The piezoelectric voltage is effectively amplified by the InSe-based FET, which has high field-effect mobility and electrical stability. The loading pressure on ZnO is analyzed by measuring the current variation of the InSe-based FET. The pressure sensor can sense a minimum load of 0.1 g corresponding to a potential of 0.2 mV. Here, we present a new strategy to construct a piezoelectric pressure sensor by integration of pressure-sensitive ZnO NR arrays with potential-sensitive InSe-based FET, the integration of flexible sensor parts and rigid micro amplifier parts benefit the realization of wearable functions with the stable signal output. Moreover, this facile fabrication would promote promising applications in flexible electronics.