Multifunctional Lead-Free Halide Perovskite-Based Nanogenerator for Enhanced Energy Harvesting and...

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 Cs₃Bi_2-xSb_xBr₉ 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. Cs₃Bi_2-xSb_xBr₉@PVDF (x = 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.