Programmable Doped Metal Oxide Nanocrystals via Continuous Growth

: Doped metal oxide nanocrystals have emerged as a versatile platform for optoelectronic, catalytic, and energy-related applications, owing to their tunable electronic structure, chemical robustness, and solution processability. Recent advances in continuous injection ("living") synthesis have transformed these materials from static products of batch reactions into programmable inorganic architectures, enabling deterministic control over size, faceting, surface chemistry, and, critically, radial dopant distribution. In this Review, we examine how precursor flux, reagent identity, and temporal dopant delivery encode growth pathways that directly map onto plasmonic response, charge transport, electrochromic behavior, and chemical reactivity. We highlight how controlled dopant placement and surface electrostatics define depletion layers and tune active nanocrystal response. Beyond optical and electronic function, we discuss emerging opportunities in catalysis, photoinduced charge storage, and chromogenic devices, where nanocrystals designed at the synthesis stage enable functionalities not accessible through postsynthetic modification alone. Finally, we outline future directions toward predictive synthesis and scalable integration, positioning continuous growth as a general design framework for next-generation functional oxide-based nanomaterials.