Investigation of nickel-63 radioisotope-powered GaN betavoltaic nuclear battery

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Aydin S., Kam E.

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, vol.43, no.14, pp.8725-8738, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 14
  • Publication Date: 2019
  • Doi Number: 10.1002/er.4871
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.8725-8738
  • Keywords: betavoltaic, gallium nitride, micro-nano electromechanical systems, nuclear battery, radioisotope, SHUNT RESISTANCE, PERFORMANCE
  • Yıldız Technical University Affiliated: Yes


This work describes the theoretical and experimental investigation of an in-house produced Ni-63 radioisotope-powered GaN-based direct conversion (betavoltaic) nuclear battery. GaN p-n junction device with 1-mm(2) area was fabricated and irradiated by the Ni-63 plate source. Short-circuit current and open-circuit voltage of the battery were measured, and current-voltage curves were plotted. The energy stored in battery, maximum power, and efficiency parameters were calculated. Monte Carlo modelling was used to investigate radioisotope's self-absorption effect, the optimization of semiconductor and source thickness, transport, and penetration of beta particles in semiconductor junction. A large fraction of beta particle energy emitted from Ni-63 source is absorbed within 1 mu m of the semiconductor junction on the basis of the simulation results. Epitaxial growth of GaN was performed using metal-organic chemical vapour deposition (MOCVD) system. Monte Carlo simulation with MCNPX was used to determine optimum Ni-63 radioactive film thickness. Ni-63 film was electroplated on one face of 1-mm(2) copper plate and mounted 1 mm over the semiconductor device. A Ni-63 source with an apparent activity of 0.31 mCi produced 0.1 +/- 0.001 nA short-circuit current (I-sc), 0.65 V +/- 0.0022 open-circuit voltage (V-oc), and 0.016 nW +/- 0.0002 maximum power (P-max) in the semiconductor device. The filling factor (FF) of the betavoltaic cell was 25%, and the conversion efficiency (& x273;) was 0.05%. Finally, experimental results were compared with theoretical calculations.