Energy harvesting and human motion sensing of a 2D piezoelectric hybrid organic–inorganic perovskite

Two-dimensional (2D) hybrid organic–inorganic perovskites (HOIPs) have garnered plentiful attention as a result of their exceptional structural flexibility and multiple applications. In this study, we present a 2D HOIP (CHA)2PbBr4 (CHA = cyclohexylamine), for its potential applications in piezoelectricity, such as strain energy sensing and harvesting. Flexible composite films of (CHA)2PbBr4/PDMS (PDMS = polydimethylsiloxane) with a sequence of weight ratios (0, 5, 10, 15, 20 wt %) of (CHA)2PbBr4 were fabricated to analyze the energy harvesting properties. Experimental results demonstrated that a device with 15% composition exhibited the most optimized performance in energy harvesting, producing a peak magnitude of output voltage of 11.6 V, a short-circuit current of 0.38 µA, and a power density of 6.77 µW/cm2, along with notable stability exceeding 4000 cycles. Furthermore, this device exhibited high sensitivity in monitoring many varieties of human movements, such as finger bending and tapping, elbow bending, and gentle foot stamping. The findings of this study indicate that this 2D HOIP holds significant potential for use in flexible sensing and intelligent wearable devices.