Pyroelectric based energy harvesting devices: hybrid structures and applications

Waste-heat management and harvesting have demonstrated significant potential in enhancing the efficiency of conventional energy utilization systems. The direct conversion of diverse thermal energies into electrical energy offers a promising solution for powering small-scale electronics directly. Pyroelectric energy harvesting has gained substantial popularity as an energy source due to its inherent capabilities. Pyroelectric and piezoelectric materials have emerged as captivating material classes, characterized by their ability to exhibit the pyroelectric phenomenon - spontaneous polarization in response to temperature fluctuations. This comprehensive review highlights the significance of pyroelectric materials and explores their wide range of applications, such as self-powered sensors, energy-harvesting devices, and wearable systems. This work also provides an overview of various endeavors to improve the performance of pyroelectric energy harvesters, ranging from material selection to design optimization. Furthermore, the review extensively discusses the hybridization of pyroelectric nanogenerators (PYNGs) with piezo- and triboelectric nanogenerators, showcasing their ability to enhance performance and enable novel applications. The review also addresses the existing challenges, potential improvements, and opportunities for hybrid energy harvesters.