ITOナノ結晶のシェルエンジニアリング：種子媒介成長と前駆体クラウディングによる可視光から赤外光までの広帯域吸収

Seed-mediated growth strategies provide a powerful platform for constructing complex nanocrystal architectures by enabling controlled shell deposition on preformed cores. Here, we report a modular synthesis of multicomponent metal oxide nanocrystals featuring compositionally modulated core-shell architectures. Specifically, indium tin oxide (ITO) nanocrystals are engineered through sequential shelling combined with tunable precursor crowdinga strategy analogous to molecular crowdingthat reinforces the local precursor concentration near the nanocrystal surface. This environment promotes diffusion-limited growth and enables anisotropic shell formation along with controlled incorporation of otherwise inaccessible transition metal dopants. Undoped shells transform from quasi-spherical to faceted cuboidal morphologies via directional crystallization, while codoping with Fe and Ni disrupts anisotropic growth and introduces visible-light absorption. Unlike conventional doping strategies, our approach yields broadband-active oxide nanocrystals with spatially controlled composition. These findings establish a versatile class of functional oxide heterostructures with tunable visible-to-NIR absorption.