Wearable thermoelectric devices offer a transformative approach to energy harvesting, providing sustainable solutions for powering next-generation technologies. In pursuit of efficient, flexible, biocompatible, and cost-effective thermoelectric materials, zinc oxide (ZnO) has emerged as a distinctive candidate due to its unique combination of favorable properties. This study explores the growth and optimization of ZnO nanorods on conductive carbon fabric (CF) using a simple microwave-assisted solvothermal technique. This method circumvents traditional complex processes that typically involve high temperatures or lengthy growth times, offering advantages such as rapid, uniform, and controllable volumetric heating. By systematically varying growth parameters, including microwave power and reaction time, we established conditions that promote the vertical alignment of ZnO nanorods, essential for enhancing thermoelectric performance. Structural and morphological analyses highlight the pivotal influence of the seed layer and growth parameters in achieving dense, uniform growth of ZnO nanorods. Interestingly, at higher microwave power levels, a transformation from nanorod structures to sheetlike morphologies was observed, likely due to Ostwald ripening, where larger particles grow at the expense of smaller ones. The optimized growth conditions for achieving superior growth and thermoelectric performance were identified as 15 min of growth at 100 W microwave power. Under these conditions, ZnO nanorods exhibited enhanced crystallinity and a higher growth rate, contributing to an improved thermoelectric power factor of 777 nW/mK2 at 373 K. This work underscores the importance of precise parameter control in tailoring ZnO nanostructures for wearable thermoelectric applications and demonstrates the potential of scalable, low-cost methods to achieve high-performance energy-harvesting materials.

Investigating the effect of microwave growth parameter regulation in the growth and thermoelectric properties of zinc oxide nanorodscarbon fabric for wearable thermoelectric application
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials and chemicals
        2.2 Pre-treatment and surface treatment of CF
        2.3 Deposition of ZnO seed layer on CF
        2.4 Preparation of ZnO nanorods on CF
    3 Results and discussions
        3.1 Structural analysis
        3.2 Morphological analysis
            3.2.1 Growth mechanism
        3.3 Chemical bonding analysis
        3.4 HALL measurement
            3.4.1 Carrier transport mechanism
        3.5 Thermoelectric analysis
    4 Conclusion
    Acknowledgements 
    References

• S. Harish(Nanotechnology Research Center, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, Tamil Nadu, India, Centre of Excellence in Materials and Advanced Technologies (CeMAT), Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, India) Corresponding author
• M. Navaneethan(Nanotechnology Research Center, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, Tamil Nadu, India, Centre of Excellence in Materials and Advanced Technologies (CeMAT), Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, India)
• C. Suresh Prasanna(Nanotechnology Research Center, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, Tamil Nadu, India, Centre of Excellence in Materials and Advanced Technologies (CeMAT), Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, India, Graduate School of Science and Technology, Shizuoka University, 3‑5‑1 Johoku, Chuo‑ku, Hamamatsu, Shizuoka 432‑8011, Japan)
• H. Hamasaki(Graduate School of Science and Technology, Shizuoka University, 3‑5‑1 Johoku, Chuo‑ku, Hamamatsu, Shizuoka 432‑8011, Japan)
• H. Ikeda(Graduate School of Science and Technology, Shizuoka University, 3‑5‑1 Johoku, Chuo‑ku, Hamamatsu, Shizuoka 432‑8011, Japan, Research Institute of Electronics, Shizuoka University, 3‑5‑1 Johoku, Chuo‑ku, Hamamatsu, Shizuoka 432‑8011, Japan)
• T. Yamakawa(Nara Institute of Science and Technology, 8916‑5 Takayama‑cho, Ikoma, Nara 630‑0192, Japan)
• K. Ikeda(Nara Institute of Science and Technology, 8916‑5 Takayama‑cho, Ikoma, Nara 630‑0192, Japan)
• Y. Hayakawa(Research Institute of Electronics, Shizuoka University, 3‑5‑1 Johoku, Chuo‑ku, Hamamatsu, Shizuoka 432‑8011, Japan)