Enhancing the Output Performance of Triboelectric Nanogenerators By Inserting CdS into Dielectric Layer

Abstract

Triboelectric nanogenerators (TENGs) have emerged as promising devices for harvesting mechanical energy from various environmental sources. In this study, we focus on enhancing the performance of TENGs by inserting nano-sized cadmium sulfide (CdS) into a polydimethylsiloxane (PDMS) material. The synthesis of CdS nanomaterials was achieved through an ultrasonication method, resulting in a significant reduction in particle size compared to commercial CdS. The fabrication process of the TENG involved dispersing CdS nanoparticles into PDMS and depositing the composite thin film onto a polyethylene terephthalate (PET) substrate. Characterization studies using field emission scanning electron microscopy (FE-SEM) and UV-visible spectroscopy confirmed the successful transformation of micron-level CdS into nano-level CdS with improved optical and morphological properties. The TENG device was assembled employing a two-electrode configuration, comprising copper foils as electrodes and the CdS/PDMS composite thin film as the friction layer. Subsequent electrical measurements were conducted to assess the TENG's performance, encompassing evaluations of open circuit voltage, short circuit current, and charge transfer density. The findings revealed that the integration of CdS nanoparticles into PDMS significantly augmented the TENG's output, manifesting in notable increases in both voltage and current in comparison to PDMS-based TENGs. Moreover, a comparison between TENGs incorporating nano-scale CdS and those utilizing micro-scale CdS exhibited superior performance of the former, attributed to the enhanced charge transfer properties facilitated by the nanoparticles. Specifically, these findings indicate a threefold enhancement in output voltage and a 2.5-fold enhancement in current compared to the initial PDMS-based TENG. Additionally, a comprehensive study on the impact of external load resistance on the TENG's output energy density demonstrated its potential for practical applications, with the device capable of powering LEDs continuously. Rectification of the TENG's output voltage using a full bridge rectifier showcased efficient conversion of mechanical energy into electrical energy without a significant performance decline. Stability tests conducted over multiple days confirmed the reliability of the TENG based on CdS/PDMS, suggesting its suitability for long-term applications. In conclusion, the integration of nano-level CdS into PDMS material presents a promising approach to enhance the TENG performance for mechanical energy harvesting. Despite challenges such as CdS agglomeration in the polymer matrix, our findings highlight the potential of CdS-based TENGs for various energy harvesting applications and pave the way for future research in optimizing their performance and stability.