Coupling of interfacial capacitance and interfacial polarization in MAPbBr3/P(VDF-TrFE) composite fibers for ultra-fast and high output self-powered pressure sensors

In this work, in-situ synthesized MAPbBr3 quantum dots were introduced as nanofillers to enhance the piezoelectric properties of P(VDF-TrFE) based nanofiber composites. MAPbBr3 quantum dots increased the β-phase content in P(VDF-TrFE) nanofibers from 79 % to 86 % via electrostatic interactions of MA-F groups, which was related to the coupling between interfacial capacitance and interfacial polarization at the interface between MAPbBr3 and P(VDF-TrFE). A high-performance flexible pressure sensor with a sensitivity of up to 1.1 V/kPa and ultra-high responsibility was demonstrated, whose open-circuit voltage up to 35.2 V, a short-circuit current of 6.2 μA and an output power of 188.41 μW were achieved in the composite containing 5% MAPbBr3. The sensor could power 47 commercial LEDs, confirming its self-powered capability. Owing to the distinctive down-conversion effect of MAPbBr3 quantum dots, the UV photodetection ability has been demonstrated and the dual sensing functionality of UV photodetection and pressure detection shows the great potential applications of the sensor in wearable multifunctional devices.