To overcome the poor source collection and utilization efficiencies of conventional planar transducers in betavoltaic isotope batteries, we design an ordered three‐dimensional nano truncated‐conical array (TCA) composite thin‐film transduction structure based on the wide‐bandgap semiconductor TiO 2 . Monte Carlo simulations combining Geant4 and CASINO are used to systematically examine the transport trajectories and energy‐deposition characteristics of β particles emitted by 63 Ni within the TCA and reference film structures. We propose an optimization strategy for TiO 2 ‐based betavoltaic transducers, focusing on how the geometry of the transduction material‐specifically truncation height, array pitch, and the thickness of the underlying TiO 2 film‐governs the spatial distribution of deposited energy, thereby revealing the key factors that limit deposition efficiency. Simulations show that for 1000 incident β particles (total energy 17.4 × 10 3 keV), a TCA with a 400‐nm TiO 2 base film, a 1200‐nm truncation height, and no inter‐array gap yields a maximum deposited energy of ∼11.6 × 10 3 keV, corresponding to an absolute deposition efficiency of ∼66.7%. Compared with a planar film, the energy‐deposition efficiency within the effective volume is increased by 7.35%. These results provide essential theoretical support and technical guidance for performance optimization of wide‐bandgap TiO 2 betavoltaic devices.
Zhou et al. (Wed,) studied this question.