biostudies-literatureJiang TNatural Science Foundation of Fujian Province (Fujian Provincial Natural Science Foundation)National Natural Science Foundation of China (National Science Foundation of China)214https://www.ebi.ac.uk/biostudies/studies/S-EPMC12170895biostudies-literatureUnknown14(1)Radio-photovoltaic cells (RPVCs) are able to offer high reliability and extended operational lifetimes, making them ideal for harsh-environment applications. However, the two-stage energy conversion process inherently limits energy conversion efficiency (ECE). This study presents a novel RPVC design based on a waveguide light concentration (WLC) scheme, employing multilayer-stacked GAGG:Ce scintillation waveguides alternately loaded with <sup>90</sup>Sr radioisotope sources. Electron beam irradiation tests revealed highly efficient radioluminescence (RL) emission from the edge surfaces of GAGG:Ce waveguide at electron energies exceeding 60 keV. A RPVC prototype incorporating 1.43 Ci of ⁹⁰Sr achieved a maximum output power (P<sub>max</sub>) of 48.9 μW, with an unprecedented ECE of 2.96%-theLight, science & applicationsHigh-efficiency <sup>90</sup>Sr radio-photovoltaic cells based on waveguide light concentration structure.PMC12170895121751902022J02006Li XLi SHan LSan HJiang TZhang LYao WTang XfalseHigh-efficiency <sup>90</sup>Sr radio-photovoltaic cells based on waveguide light concentration structure.Radio-photovoltaic cells (RPVCs) are able to offer high reliability and extended operational lifetimes, making them ideal for harsh-environment applications. However, the two-stage energy conversion process inherently limits energy conversion efficiency (ECE). This study presents a novel RPVC design based on a waveguide light concentration (WLC) scheme, employing multilayer-stacked GAGG:Ce scintillation waveguides alternately loaded with <sup>90</sup>Sr radioisotope sources. Electron beam irradiation tests revealed highly efficient radioluminescence (RL) emission from the edge surfaces of GAGG:Ce waveguide at electron energies exceeding 60 keV. A RPVC prototype incorporating 1.43 Ci of ⁹⁰Sr achieved a maximum output power (P<sub>max</sub>) of 48.9 μW, with an unprecedented ECE of 2.96%-the2025-01-01T00:00:00Z2025 Jun2025-07-26T03:07:24.784Z2025-07-26T03:07:24.784ZS-EPMC121708954052388210.1038/s41377-025-01875-1