Compact Photo‐Pyroelectric Energy Harvester With High Energy Density and Rapid Discharge Speed

Abstract The rapid growth of micro‐devices demands power supplies with remote self‐powering, high energy density, and high power capability, thereby driving continuous advancements in energy harvesting technology. Here, a novel photo‐pyroelectric energy harvester based on poly(vinylidene difluoride‐trifluoroethylene) P(VDF‐TrFE) ferroelectric polymer is presented, addressing the limitations of conventional pyroelectric energy harvesting technologies, particularly their low energy and power densities. The unique photothermal effect of nanostructured Au electrode on the polymer generates rapid temperature oscillations of the polymer under visible light, enabling efficient pyroelectric energy harvesting. The harvester achieves a highest energy density of 4.75 J cm −3 and a highest power density of 1711.9 W cm −3 , surpassing existing pyroelectric energy harvesters. Furthermore, functioning as dielectric capacitors, the Au metallized polymer films exhibit a photo‐capacitance effect as high as 281%, allowing for greatly enhanced energy storage and power conditioning capabilities via light irradiation. In addition, the successful combination of pyroelectric energy harvesting and electrostatic energy storage, which are often considered to be incompatible in term of energy generating mechanism and energy release speed, in one material offers a promising strategy for developing compact energy supply and power conditioning devices for various applications.