Size-ordered ⁶³Ni nanocluster film as a betavoltaic battery unit

We create thin metallic films formed as a size-ordered deposition of Ni nanoclusters whose sizes are distributed over the range of 2–7 nm. The morphology, chemical composition, and electrical characteristics of the films are measured. The conductivity of the films under investigation changes approximately as the inverse square root of the average nanocluster size. We observe experimentally that, under irradiation by electrons with energies of 10–25 keV, the films show signs of being subjected to the electromotive force. We discuss how this effect is connected with the size-ordered spatial distribution of metallic nanoclusters. We analyze the possibility of using ⁶³Ni nanocluster films in betavoltaic battery units and estimate the expected efficiency of converting β-decay energy into electricity.