Lead-free halide perovskite (LFHP) materials have recently received a lot of attention in optoelectronic applications due to their low toxicity and outstanding optical characteristics. Simultaneously, the increased thrust for flexible, wearable, and lightweight optoelectronic devices is driving improvements in sensor and actuator technology. In this context, flexible piezoelectric polymer composites based on LFHPs are gaining popularity due to their exceptional piezoelectric, pyroelectric, ferroelectric, and optical traits. Thus, this investigation presents long-term stable lead-free rubidium copper chloride (Rb2CuCl3)-based poly(vinylidene fluoride) composites. The optimized PVDF/Rb2CuCl3 composite yields similar to 92.4% of the electroactive phase of the PVDF. Interfacial interactions between PVDF and Rb2CuCl3 have played a pivotal role in the electroactive beta-phase transformation, resulting in improved long-term stability. A piezoelectric nanogenerator (PENG) has been fabricated employing the PVDF/Rb2CuCl3 composite for mechanical energy harvesting and biophysiological motion monitoring, demonstrating potential applications in the healthcare industry. The Piezoelectric Energy Harvester (PEH) with the PRCC_2.5 composite (PVDF composite of 2.5 wt % Rb2CuCl3) outperformed other composites, with a maximum open-circuit voltage (V oc) of similar to 51.7 V and a short-circuit current (I sc) of similar to 4.6 mu A. The pristine PVDF-based device (PEH 0) had inferior performance, with a V oc of similar to 12 V and an I sc of similar to 0.5 mu A. PEH 2.5 device exhibited a charge of similar to 126 nC, which is far higher than the PEH 0 for which the corresponding charge was similar to 7 nC. Furthermore, during the periodic application of the force of similar to 5 N, the stability and durability of the PEH 2.5 device were evaluated. 10,250 compression cycles were used to measure the electrical output of the PEH 2.5 device. Remarkably, following the 10,250 cycles, there was no discernible drop in the output voltage (similar to 16 V). In addition, a photodetector has been developed to investigate the piezo-phototronic effect, displaying quick photoswitching behavior with rise and decay periods of similar to 3.22 and similar to 5.48 s, respectively. These findings demonstrate that the flexible PVDF/Rb2CuCl3 composites have significant potential as an optical signal-modulated piezoresponsive wearable sensor.
