Title
Chain-Length Dependence of Thermal Conductivity in 2D Alkylammonium Lead Iodide Single Crystals
Document Type
Article
Date of Original Version
12-2-2020
Abstract
In 2D organic-inorganic hybrid perovskite materials, layers of conducting inorganic material are separated by insulating organic spacers whose length and composition can be tuned. We report the heat capacity and cross-plane thermal conductivity of 2D alkylammonium lead iodide single crystals with increasing chain length, (CnH2n+1NH3)2PbI4 (n = 4-7). The measured thermal conductivities are some of the lowest ever recorded for single crystals, with averages in the range k = 0.099-0.125 W/m K. Although a model based on independent interface resistances between adjacent layers predicts an increase in thermal conductivity with a chain length of more than 30%, experimentally we find that the thermal conductivity is nearly independent of chain length and possibly decreases. We hypothesize that phonons carry an appreciable portion of the heat across the interface coherently, rather than being limited by individual weak interfaces.
Publication Title, e.g., Journal
ACS Applied Materials and Interfaces
Volume
12
Issue
48
Citation/Publisher Attribution
Rasel, Md Abu Jafar, Ashutosh Giri, David H. Olson, Chaoying Ni, Patrick E. Hopkins, and Joseph P. Feser. "Chain-Length Dependence of Thermal Conductivity in 2D Alkylammonium Lead Iodide Single Crystals." ACS Applied Materials and Interfaces 12, 48 (2020): 53705-53711. doi: 10.1021/acsami.0c10894.