Proton/Electron Irradiation Effects On MAPbI₃ And Mixed-cation Perovskite Films And Solar Cells

Perovskite solar cells（PSCs）are considered as one of the most promising candidates for next-generation space photovoltaic devices due to their high efficiency,low cost,high specific power,and irradiation resistance significantly superior to silicon-based and III-V compound solar cells.In order to promote the space application process of perovskite solar cells,it is necessary to improve the research on space irradiation effect.By investigating the progress of irradiation effects research on perovskite solar cells at home and abroad,it is found that there are still deficiencies in understanding the irradiation damage mechanism of the perovskite active layer at the core of photovoltaic devices and the synergistic effect of multiple irradiation sources.In this paper,taking the classic organic-inorganic perovskite component CH₃NH₃Pb I₃（MAPbI₃）as an entry point,and then introducing Cs⁺and NH₂CH=NH₂⁺（FA⁺）,combined with simulation calculations and experiments,the proton irradiation effect and damage mechanism of MAPbI3,Csx MA1-x Pb I3 and Cs0.05（FA0.83MA0.17）0.95Pb（I0.83Br0.17）3perovskite films were studied.Finally,a comparative analysis was conducted to study the impact mechanisms of proton/electron single-particle irradiation and proton-electron sequential irradiation on perovskite films.Additionally,the irradiation effects on corresponding perovskite solar cells were investigated.The proton irradiation-induced damage mechanism of perovskite films in the core layer of solar cells was investigated using classic MAPbI₃ composition.Proton irradiation experiments were conducted with proton energy of 50 ke V and fluences range of 1×10¹³ to 1×10¹⁵ p cm^-2.The results showed that MAPbI₃ films and perovskite solar cells could withstand proton irradiation up to the fluence of1×10¹⁴ p cm^-2 without significant performance degradation,with MAPbI₃-PSCs still maintaining over 90%of initial efficiency after irradiation.Combining experiments with SRIM simulations,it was confirmed that due to the combined effects of displacement damage and total dose effect,high-fluence proton irradiation of 1×10¹⁵ p cm^-2 would break the covalent bonds of methylammonium groups in MAPbI₃,causing partial amorphization of the films and degradation of their performance.Moreover,high-fluence proton irradiation could break the methoxyphenyl groups in Spiro-OMe TAD hole transport layer,greatly weakening its hole transport ability,resulting in complete failure of solar cell.The proton irradiation effects on mixed-cation perovskite films and solar cells were investigated.By calculating the crystal structure tolerance factor and cohesive energy of Cs_xMA_1-xPb I₃ perovskite,and analyzing the changes in film’s structure and properties under different fluences of proton irradiation,it was found that doping with 5%Cs ions effectively enhanced the proton irradiation resistance of MAPbI₃ films.Considering the poor photothermal stability of MA⁺,Cs⁺and FA⁺were simultaneously introduced to investigate the proton irradiation effects on Cs_0.05(FA_0.83MA_0.17)_0.95Pb(I_0.83Br_0.17)₃ ternary-cation（CsFAMA）perovskite films.By comparing the performance degradation of different perovskite films under proton irradiation,it was found that CsFAMA film exhibits better stability and irradiation resistance.After proton irradiation with 2×10¹⁴ p cm^-2,the CsFAMA-PSCs maintained an efficiency of approximately 15%even after natural aging for 64 days,demonstrating excellent irradiation performance stability.The proton-electron sequential irradiation effects on perovskite films and their corresponding solar cells were studied.MAPbI₃ and CsFAMA were used as the research objects to conduct single-particle irradiation and proton-electron sequential irradiation tests,with proton irradiation at 60 ke V and a total fluence of2×10¹⁴ p cm^-2,and electron irradiation at 100 ke V and a total fluence of 2×10¹⁵ e cm^-2,respectively.The results indicated that compared to proton irradiation,the perovskite films subjected to sequential irradiation exhibited less performance degradation,with lower efficiency attenuation in the solar cells,demonstrating better irradiation performance stability.This is attributed to the annealing effect of electron irradiation in the sequential irradiation process on the defects induced by preceding proton irradiation.Due to the small ion/atom migration barrier and high charge carrier mobility of perovskite,electron irradiation can facilitate the rearrangement of atoms and charges in perovskite more easily,thereby accelerating the repair of proton irradiation defects.