Exploring the Limits: Degradation Behavior of Lead Halide Perovskite Films under Exposure to Ultrahigh Doses of γ Rays of Up to 10 MGy

Abstract

Herein, we show that thin films of MAPbI 3 , FAPbI 3 , (CsMA)PbI 3 , and (CsMAFA)PbI 3 , where MA and FA are methylammonium and formamidinium cations, respectively, tolerate ultrahigh doses of γ rays approaching 10 MGy without significant changes in their absorption spectra. However, among the studied materials, FAPbI 3 was the only one that did not form metallic lead due to its extreme radiation hardness. Infrared nearfield optical microscopy revealed the radiation-induced depletion of organic cations from the grains of MAPbI 3 and their accumulation at the grain boundaries, whereas FAPbI 3 on the contrary lost FA cations from the grain boundaries. The multication (CsMAFA)PbI 3 perovskite underwent a facile phase segregation to domains enriched with MA and FA cations, which is a principally new radiation-induced degradation pathway. Our findings suggest that the radiation hardness of the rationally designed perovskite semiconductors could go far beyond the impressive threshold of 10 MGy we set herein for FAPbI 3 films, which opens many exciting opportunities for practical implementation of these materials.

Proton Irradiation on Halide Perovskites: Numerical Calculations

“…Furthermore, we present, for the first time, the calculation of the radiation-induced activation effect in hybrid perovskites. The obtained data confirm the previous results from the gamma and electron stability studies, which show that FAPbI 3 perovskite has a great potential for use in space [ 30 ]. On the other hand, we have shown the importance of taking into account the lateral distribution of the incident proton beam throughout the entire depth of the solar cell.…”

“…Among all perovskite compositions, the least energy transfer from protons to all channels (ionization, displacement and heating) is demonstrated by the MAPbI 3 , FAPbBr 3 and FAPbI 3 compounds (Supplementary Figures S2-S13). This is also supported by the results of gamma-ray and electron resistance studies, which show that the FAPbI 3 has great potential for use in space [30].…”

Gamma-ray dose threshold for MAPbI3 solar cells

“…Moreover, solar cells based on MAPbI 3 showed remarkably good stability in comparison with mixed cation systems. However, later publications 22 showed that extreme doses beyond 10–100 kGy have a negative impact on MAPbI 3 and this led us to a proposal to determine the gamma-ray threshold for MAPbI 3 perovskite. Here, we exposed MAPbI 3 films and solar cells to gamma-ray doses: 3, 5, 10 and 21 kGy.…”

“…11 To imitate space radiation on the Earth, various facilities with different particles and energies are used: protons, 12,13 electrons, 2,14 X-rays 10,15,16 and gamma-rays. 5,[7][8][9][17][18][19][20][21][22] Normally, electron irradiation is used due to the vast availability of electron beam setups. However, Ahmad R. Kirmani suggested that proton irradiation with low energies up to 1 MeV is a more accurate way to estimate the radiation hardness of perovskites.…”

Composition dependence of X-ray stability and degradation mechanisms at lead halide perovskite single crystal surfaces

“…Other studies in literature compared MAPbI 3 , FAPbI 3 , Cs x MA 1− x PbI 3 and Cs x MA y FA 1− x − y PbI 3 thin films after exposure to a controlled amount of γ radiation and observed a formation of Pb 0 for all compositions except FAPbI 3 . 19 MAPbI 3 thin films were investigated via PES under ultrahigh vacuum conditions and it was reported that soft X-rays caused a rapid decomposition of the organic cation and, after long exposure, also the formation of metallic lead. 20 Furthermore, a comparative stability study on MAPbI 3 , MAPbBr 3 , Cs 0.15 FA 0.85 PbI 3 , Cs 0.1 MA 0.15 FA 0.75 PbI 3 , CsPbI 3 , and CsPbBr 3 thin films using PES and XRD has shown no γ-ray radiation damage on most compositions, except MAPbI 3 and CsPbI 3 .…”