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DOE OSTI · 3374372

Quantifying Size Effects on Thermal Transport in CsPbBr 3 Nanocrystal Films

Park, Jee Yung [Yale Univ., New Haven, CT (United States)] (ORCID:0000000298146563)·Chen, Du [Yale Univ., New Haven, CT (United States)] (ORCID:0000000276048786)·Li, Shunran [Yale Univ., New Haven, CT (United States)] (ORCID:000000030428295X)·Xia, Yi [Portland State Univ., OR (United States)]·Diroll, Benjamin T. [Argonne National Laboratory (ANL), Lemont, IL (United States). Center for Nanoscale Materials (CNM)] (ORCID:0000000334880213)·Guo, Peijun [Yale Univ., New Haven, CT (United States)] (ORCID:0000000157327061)
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Abstract

Colloidal lead halide perovskite nanocrystals (LHP NCs) are promising semiconductor materials for optoelectronic applications due to their strong quantum confinement, near-unity photoluminescence quantum yields, and tunable emission characteristics. However, their modest thermal stability remains a challenge, particularly at smaller core diameters due to enhanced phonon scattering at inorganic core-organic ligand interfaces. In this work, we directly quantify size-dependent thermal conductivity (κ) in lecithin-capped CsPbBr 3 NC thin films using a transducer-free, vibrational pump–visible probe (VPVP) spectroscopy technique. A mid-infrared pump thermally excites the ligand shell, while a broadband probe tracks transient reflectance change correlated to lattice temperature decay. Finite-element modeling of the decay dynamics yields κ values from 0.13 to 0.16 W·m –1 ·K –1 for NC films with sub-10 nm core diameter, significantly lower than those of its bulk counterpart. A steep κ suppression with decreasing NC size emphasizes the dominant role of ligand shells and boundary effects in thermal transport.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYmetal-halide perovskitesnanocrystal thin filmspump−probe spectroscopythermal conductivitythermal transport

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Park, Jee Yung [Yale Univ., New Haven, CT (United States)] (ORCID:0000000298146563), Chen, Du [Yale Univ., New Haven, CT (United States)] (ORCID:0000000276048786), Li, Shunran [Yale Univ., New Haven, CT (United States)] (ORCID:000000030428295X), Xia, Yi [Portland State Univ., OR (United States)], Diroll, Benjamin T. [Argonne National Laboratory (ANL), Lemont, IL (United States). Center for Nanoscale Materials (CNM)] (ORCID:0000000334880213), Guo, Peijun [Yale Univ., New Haven, CT (United States)] (ORCID:0000000157327061). 2025-09-23. Quantifying Size Effects on Thermal Transport in CsPbBr 3 Nanocrystal Films. https://doi.org/10.1021/acs.nanolett.5c03215

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