Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 148697

148697 - Radiation-Induced Mechanical Property Change in 2d Metal Halide Perovskites 

Metal Halide Perovskite (MHP) solar cells exhibit significant potential for space applications due to their high efficiency and adaptability for lightweight, flexible designs. However, their long-term operational stability is compromised by the harsh space radiation environment. Understanding the radiation effects on the mechanical properties of MHPs is crucial for enhancing their durability in space applications. In this study, we exposed the materials to various doses of x-ray irradiation to simulate the space radiation environment, and quantitatively assessed the out-of-plane elastic modulus (E) and hardness (H) of 2D MHPs using nanoindentation. We focused on prototypical 2D MHPs, (C₄H₉-NH₃)₂ (CH₃NH₃)_n-1 Pb_nX_3n+1 (n = 1 to 5; X = I, Br, or Cl), and explored how the radiation-induced mechanical property change as a function of their chemical composition. Our findings demonstrate that both E and H of (C₄H₉-NH₃)₂ (CH₃NH₃)₂ Pb₃I₁₀ first decline sharply as the radiation dose increases from 0 to 1.42 Mrads, subsequently reaching a plateau. This rapid degradation phase suggests significant initial structural damage, followed by a stabilization phase where further radiation exposure does not substantially exacerbate the deterioration. To further explore the impact of halide composition on radiation resistance, we substituted iodine with other halogen elements in the 2D MHPs. The result shows that Br-based 2D MHPs exhibited superior resistance to radiation-induced mechanical degradation, highlighting the critical role of halide composition in enhancing the radiation tolerance of 2D MHPs regarding their mechanical behavior. The sensitivity of mechanical property changes to the thickness of the inorganic metal-halide framework in each repeating unit (indicated by n in the chemical formula) of the 2D MHPs was also investigated. Variations in framework thickness revealed distinct degradation patterns, indicating a complex interplay between structural dimensions and radiation resistance. In addition to x-ray irradiation, we examined the effects of proton radiation by exposing the 2D MHPs to 1 MeV protons at a flux of 10¹² cm⁻²s⁻¹ for various amount of time (up to 34 minutes). The results paralleled those obtained from x-ray irradiation, with both E and H decreasing significantly with increased proton radiation dosage, followed by a plateau. This concordance may suggest a common underlying damage mechanism influencing the mechanical properties under different types of radiation. To elucidate the underlying damage mechanisms, we correlated our nanoindentation results with photoluminescence and structural changes observed in the materials. This comprehensive approach provided insights into the factors contributing to radiation-induced damage and informed strategies for designing more robust MHPs for space applications.

Presenting Author: Shengjia Zhang Texas A&M University

Presenting Author Biography: I am a PhD student with Dr. Qing Tu in the Department of Materials Science & Engineering at Texas A&M University (TAMU). I received my bachelor's degree in Material Molding and control Engineering in China University of Petroleum(UPC) in 2021 and MS in Material Science and Engineering from UC San Diego in 2023 before join Dr. Tu 's lab. I am interested in understanding and engineering the mechanical properties in advanced functional materials (e.g., 2D materials, hybrid organic-inorganic perovskites, metal organic framework) for better design and optimize their functional properties for applications.

Authors:

Shengjia Zhang Texas A&M University
Merlyn Pulikkathara Prairie View A&M University
Eugenia Vasileiadou Northwestern University
Ioannis Spanopoulos University of South Florida
Mercouri Kanatzidis Northwestern University
Richard Wilkins Prairie View A&M University
Qing Tu Texas A&M University