Charlie Chandler

Mixed organic–inorganic halide perovskites are finding strong interest as thin film solar cell materials. XPS depth profiling of a spin‐coated (FAPbI 3 ) 0.95 (MAPbBr 3 ) 0.05 perovskite thin‐film solar cell, has been performed. Profiles have been recorded using traditional monatomic and cluster ion beam bombardment and compared to those obtained using a new femtosecond laser ablation (fs‐LA) approach. The femtosecond laser employed has a wavelength of 1030 nm and a pulse length of 160 fs. Monatomic and cluster ion sputter depth profiling of the halide perovskite results in preferential sputtering of C, N and I and the appearance of Pb 0 in the Pb 4f spectrum as a preferential sputtering artefact. fs‐LA depth profiling is shown to retain the original composition and chemical state information of the perovskite layer with no chemical damage. An ablation rate of ≈33 nm through the perovskite layer was found at an incident laser energy of 42 μJ per pulse. A combined fs‐LA/monatomic sputtering depth profile enabled all layers in the cell to be identified whilst retaining the true composition of the perovskite layer.

Context & scale As space exploration accelerates, the demand for advanced satellite technologies has surged, driving the satellite solar panel market to $1.53 billion by 2023. Space-grade solar cells must withstand extreme radiation while maintaining high efficiency and specific power. Although multi-junction III-V solar cells dominate due to their superior performance, their high cost has spurred interest in alternative, cost-effective photovoltaic technologies. Perovskite solar cells (PSCs) have emerged as strong candidates, offering robust radiation tolerance and high specific power. However, damage to A-site organic cations caused by proton irradiation remains a key challenge, hindering their self-healing potential and stability. Addressing this issue is critical for enabling PSCs in radiation-intense space environments. Summary Perovskite solar cells (PSCs) for space applications have garnered significant attention due to their high tolerance to proton radiation. While the self-healing mechanism of PSCs is largely attributed to mobile inorganic halide ions, the effects of radiation on organic A-site cations remain underexplored. In this study, wide-band-gap Cs/formamidinium (FA) PSCs, which are promising for tandem applications in space environments, were subjected to harsh proton radiation testing. Photovoltaic (PV) device parameters of the PSCs measured pre- and post-irradiation demonstrated that propane-1,3-diammonium iodide (PDAI2) treatment effectively mitigates radiation-induced damage to the perovskite layer. Advanced characterization techniques, including X-ray photoelectron spectroscopy (XPS) depth profiling using femtosecond laser ablation (fs-LA) and time-of-flight elastic recoil detection analysis (ToF-ERDA), were employed to analyze the impact of proton radiation on A-site organic cations. Additionally, time-resolved Kelvin probe force microscopy (tr-KPFM) was utilized to elucidate the mechanism by which PDAI2 treatment mitigates proton-induced damage to the organic cations.