High Efficiency Formamidinium-Cesium Perovskite-Based Radio-Photovoltaic Cells

Radio-photovoltaic cell is a micro nuclear battery for devices operating in extreme environments, which converts the decay energy of a radioisotope into electric energy by using a phosphor and a photovoltaic converter. Many phosphors with high light yield and good environmental stability have been developed, but the performance of radio-photovoltaic cells remains far behind expectations in terms of power density and power conversion efficiency, because of the poor photoelectric conversion efficiency of traditional photovoltaic converters under low-light conditions. This paper reports an radio-photovoltaic cell based on an intrinsically stable formamidinium-cesium perovskite photovoltaic converter exhibiting a wide light wavelength response from 300 to 800 nm, high open-circuit voltage (V_OC), and remarkable efficiency at low-light intensity. When a He ions accelerator is adopted as a mimicked α radioisotope source with an equivalent activity of 0.83 mCi cm⁻², the formamidinium-cesium perovskite radio-photovoltaic cell achieves a V_OC of 0.498 V, a short-circuit current (J_SC) of 423.94 nA cm⁻², and a remarkable power conversion efficiency of 0.886%, which is 6.6 times that of the Si reference radio-photovoltaic cell, as well as the highest among all radio-photovoltaic cells reported so far. This work provides a theoretical basis for enhancing the performance of radio-photovoltaic cells.