ISSN Print: 1049-0787
ISSN Online: 2375-0294
Indexed in
THERMAL TRANSPORT IN NANOSTRUCTURED ORGANIC-INORGANIC HYBRID MATERIALS
ABSTRACT
Nanostructured organic-inorganic hybrid materials hold promise as scalable materials with novel properties that emerge based on the choice of organic and inorganic constituents. These tunable materials have applications in electronics, optoelectronics, energy storage, and energy conversion, where heat is either a focal point in the design, or a parasitic byproduct of operation that must be effectively managed to optimize device performance. Herein, we review the theory and measurement of thermal transport in a wide range of organic-inorganic hybrid materials including single-molecule junctions, self-assembled monolayers, nanocrystal suspensions, nanocrystal arrays, polymer-nanostructure composites, and organic-inorganic molecular crystals. Experiments on self-assembled monolayers find that thermal interface conductance is dominated by phonons and limited by adhesion and vibrational alignment at the organic-inorganic interface. This finite thermal interface conductance bears on the thermal conductivity of nanostructured hybrid composite materials that have extensive internal interfaces. By comparison, little is known about thermal transport in hybrid molecular crystals−a relatively new class of materials that stems from the chemistry of organic and inorganic building blocks ~1 nm in size. Emergent superstructures are less aptly described as composites and instead as unique new crystals (e.g., organic-inorganic perovskites). To complement our review of experimental findings, we discuss theoretical findings and focus on analytical tools that offer a predictive capability for the intelligent design of new hybrid materials. In particular, we consider modified versions of the diffuse mismatch model for predicting thermal interface conductance and several effective medium approximations to predict the thermal conductivity of hybrid materials.