Multifunctional Lead-Free Halide Perovskite-Based Nanogenerator for Enhanced Energy Harvesting and Information-Encrypted Transmission

Halide perovskite nanocrystals (NCs) have shown excellent optoelectronic properties, but the material's moisture stability is compromised, and the fundamental limitations due to the toxicity of lead form a major roadblock toward the commercialization of any such devices. We report the synthesis of lead-free all-inorganic Cs₃Bi₂_-<i>_x</i>Sb_<i>x</i>Br₉ perovskite nanocrystals, which can be implemented efficiently in piezo/triboelectric (PTE) nanogenerators for encrypting information and wireless signal transmission. In this work, antimony (Sb³⁺) doping in lead-free perovskite NCs has been carried out to boost the nanogenerator performance of pristine PVDF material. Cs₃Bi₂_-<i>x</i>Sb_<i>x</i>Br₉@PVDF (<i>x</i> = 0.05) resulted in improved piezoelectric as well as triboelectric properties due to the formation of an enhanced electroactive β-phase of ∼91%, up from 48%. Benefiting from the doping strategies, the devices exhibited an open-circuit voltage of ∼161.2 V with a maximum power density of ∼58.37 μW/cm². This study shows the Cs₃Bi_1.95Sb_0.05Br₉@PVDF composite is an eligible candidate for high-performance nanogenerators, making it potentially robust for motion-sensing devices. Further, to showcase the practical applicability of these wearable devices, Morse codes were generated through small mechanical forces. The codes obtained were decoded through a Python program for wireless signal transmission, which can be beneficial for safety or any such autonomous communications involving low power consumption.