Heat generation, multiscale thermal transport and thermal management in colloidal quantum-dot assemblies and devices

Abstract Colloidal quantum dots (QDs) combine size-tunable electronic structure, high photoluminescence efficiency and solution processability, but they also present an unusual thermal-transport challenge: heat is generated within ultrathin, multilayer device stacks and must be removed through hybrid inorganic-organic assemblies whose cross-plane thermal conductivity is often only 0.1–0.4 W m -1 K -1 . This Review connects four bodies of work that are often considered separately: heat generation in QD light-emitting and lasing devices; multiscale thermal transport through QD cores, surface ligands, interparticle junctions and extended assemblies; experimental and computational methods for resolving these processes; and device-level thermal-management strategies. At the material scale, surface chemistry, ligand crosslinking, molecular packing, structural order, voids and particle anisotropy collectively regulate heat flow. At the device scale, resistive losses, carrier leakage, non-radiative recombination, substrates, buried interfaces, encapsulation, current distribution and operating waveform jointly determine temperature. A central conclusion is that isolated-film thermal conductivity alone cannot predict active-layer temperature: directional film conductivities, QD/transport-layer thermal boundary conductances, heat-source distribution and external thermal boundary conditions must be considered together. Direct evidence remains particularly limited for two-dimensional QD assemblies, buried QD/organic thermal interfaces and closed-loop studies linking molecular or structural design to thermal properties, operating temperature and device lifetime. We therefore outline standardized evaluation metrics and a multiscale experiment-model framework for electrothermal-optical co-design of high-brightness emitters, lasers, flexible devices and thermoelectric QD solids.