A stacking strategy for diamond betavoltaic batteries via 1 MeV electron beam simulation of 90Sr / 90Y radiation

Betavoltaic nuclear batteries are promising power supplies for extreme environments due to their high energy density and longevity. Diamond is an exceptional transducer material owing to its ultrawide bandgap and radiation hardness; however, its performance under high-energy 90 Sr / 90 Y irradiation remains under-explored. This study evaluates a diamond nuclear battery using a 1 MeV electron beam to approximately simulate the average energy of 90 Y decay. At an activity of 27 Ci/cm 2 , the device achieved an open-circuit voltage of 1.91 V, a short-circuit current of 5.2 μA, and a maximum output power of 5.8 μW. Energy deposition profiles were modeled via Monte Carlo simulations, and electrical performance was systematically investigated across varying activities and doses. An idealized analytical model was developed to extract key parameters and optimize the battery architecture. Building on this, two vertically-stacked configurations were proposed: a 25-layer parallel design and a 24-layer series design, yielding theoretical power limits of 88.285 μW and 70.6 μW, respectively. No significant degradation in battery performance was observed at a total radiation flux of 3.33 × 10 14 e/cm 2 , confirming the reliability and stability of the diamond battery when utilizing a 1 MeV electron beam to simulate a 90 Sr / 90 Y source. Finally, ultimately, this work presents a robust structural optimization strategy to enhance the energy utilization efficiency of high-energy radiation sources.