Anomalous Correlation between Thermal Conductivity and Elastic Modulus in Two-Dimensional Hybrid Metal Halide Perovskites. Academic Article uri icon


  • Device-level implementation of soft materials for energy conversion and thermal management demands a comprehensive understanding of their thermal conductivity and elastic modulus to mitigate thermo-mechanical challenges and ensure long-term stability. Thermal conductivity and elastic modulus are usually positively correlated in soft materials, such as amorphous macromolecules, which poses a challenge to discover materials that are either soft and thermally conductive or hard and thermally insulative. Here, we show anomalous correlations of thermal conductivity and elastic modulus in two-dimensional (2D) hybrid organic-inorganic perovskites (HOIP) by engineering the molecular interactions between organic cations. By replacing conventional alkyl-alkyl and aryl-aryl type organic interactions with mixed alkyl-aryl interactions, we observe an enhancement in elastic modulus with a reduction in thermal conductivity. This anomalous dependence provides a route to engineer thermal conductivity and elastic modulus independently and a guideline to search for better thermal management materials. Further, introducing chirality into the organic cation induces a molecular packing that leads to the same thermal conductivity and elastic modulus regardless of the composition across all half-chiral 2D HOIPs. This finding provides substantial leeway for further investigations in chiral 2D HOIPs to tune optoelectronic properties without compromising thermal and mechanical stability.

published proceedings

  • ACS Nano

author list (cited authors)

  • Negi, A., Yan, L., Yang, C., Yu, Y., Kim, D., Mukherjee, S., ... Liu, J.

complete list of authors

  • Negi, Ankit||Yan, Liang||Yang, Cong||Yu, Yeonju||Kim, Doyun||Mukherjee, Subhrangsu||Comstock, Andrew H||Raza, Saqlain||Wang, Ziqi||Sun, Dali||Ade, Harald||Tu, Qing||You, Wei||Liu, Jun

publication date

  • May 2024