Tenfold efficiency improvement of x-ray radioluminescent batteries basing on GAGG:Ce single crystal scintillators

Abstract

Low energy conversion efficiency and low output power are the major limiting factors of isotope batteries as miniature power supplies for the broad applications, such as micro-electromechanical systems and aerospace electronics. In this work, highly efficient x-ray radioluminescent batteries are demonstrated based on single-crystal scintillators and spectra-matched photovoltaic batteries. X-ray sources are chosen to reduce the backscattering loss, and cerium doped Gd3Al2Ga3O12 (GAGG:Ce) single-crystal scintillators are adopted to improve the radioluminescence efficiency and light coupling efficiency, for their high x-ray absorption ability and high light-yield. The bandgap of photovoltaic battery is also optimized to match the luminescence spectrum of GAGG:Ce to maximize the photovoltaic efficiency. An optimal radioluminescent battery is achieved with an output power of 13.4 μW/cm2 and a conversion efficiency of 1.28%, which is a 10.7-times improvement in the previous best reports (0.12%). This exciting progress indicates the promising potential of radioluminescent batteries in broad applications and will inspire the further exploration for the research community of radioisotope batteries.