Evaluating the Resistance of Bifacial Perovskite Photodetectors to Xenon Ion Irradiation

Abstract In this work, high‐performance bifacial perovskite photodetectors (BPPDs) are systematically investigated before and after xenon ion irradiation with energy 1.75 MeV nucleon ⁻¹ (231 MeV) and fluences up to 10 ¹¹ nucleons cm ⁻² , simulating extreme radiation environments. A comprehensive characterization of the materials used in the device's functional layers is conducted, accompanied by an in‐depth analysis of device performance before and after irradiation. Before irradiation, the devices exhibited good performance, with responsivity ( R ) of 0.39 A W ⁻¹ (front side) and 0.33 A W ⁻¹ (back side), detectivity ( D* ) of 2.4 × 10 ¹¹ and 2.0 × 10 ¹¹ Jones. At low fluence (10 ¹⁰ nucleons cm ⁻² ): R slightly decreased to 0.37/0.31 A W ⁻¹ , while D* increased to 4.4 × 10 ¹¹ /3.7 × 10 ¹¹ Jones due to an increase in shunt resistance. At higher fluence (10 ¹¹ nucleons cm ⁻² ), irradiation induced high defect formation within the functional layers, causing pronounced degradation: R dropped to 0.25/0.18 A W ⁻¹ , D* dropped to 2.8 × 10 ¹¹ /2.2 × 10 ¹¹ Jones. Despite these changes, the devices retained over 60% of their initial performance and maintained low spectral noise density, confirming notable radiation tolerance. The synergy of bifaciality and radiation resistance highlights the potential of BPPDs for reliable operation under harsh radiation conditions, offering a promising solution for future optoelectronic applications in radiation‐exposed environments.