A metric for evaluating the pyroelectric conversion efficiency of pyroelectric nanogenerators

Pyroelectric nanogenerator (PyNG) technology has gradually become the most promising technology in the field of high-entropy energy harvest. However, due to the diversity of PyNG types, it is difficult to compare their superiorities uniformly, which poses a challenge in the development and optimization of PyNG. This article quantifies the “thermal input” of the PyNG by introducing the physical quantity of heat flux, and quantifies the “electrical output” of the PyNG by citing output power density. Further the evaluation metric for PyNG: pyroelectric conversion efficiency (PCE) has been derived. Then, a testing device capable of simultaneously detecting the heat flux and output electrical characteristics of PyNG was fabricated used to measure the pyroelectric conversion efficiency. Three groups of PyNGs with different components (P(VDF-TrFE)-BaTiO3) were used in the PCE experiment, and their precise PCE were measured for the first time through a series of experiments. The optimum PCE of these three PyNGs are: 2.05 × 10-4, 2.7 × 10-4, and 3.19 × 10-4. This study establishes a metric for quantitatively and accurately characterizing pyroelectric conversion efficiency, and delivering simpler, and more intuitive results. The evaluation metric can provide a reference direction for the research and optimization of PyNG.