Instant Synthesis of Quantum Defects Using Feasible Chemistry With Distinctive Spectral Fingerprints

Quantum emitters (QEs), pivotal for quantum technologies, face scalability and sustainability challenges due to energy‐intensive fabrication and hazardous reagents in the conventional fabrication process. Here, we present a one pot incorporation strategy for swift and on‐demand QE synthesis on semiconducting single‐walled carbon nanotubes (SWCNTs) via redox‐mediated chemistry. By leveraging ferrocyanide ions as benign reducing reagents, aryldiazonium salts are efficiently activated to generate quantum defects on SWCNTs within minutes under ambient conditions. This approach eliminates external stimuli, coupling real‐time reaction monitoring to distinctive spectral fingerprints: defect‐induced near‐infrared photoluminescence and ferricyanide's optical absorption. Cross‐validated spectral signatures ensure synthesis reproducibility, while surfactant/powder compatibility demonstrates scalable production. Compared to prior methods requiring long time, external stimuli, or harsh protocols, our strategy offers unique advantages, including minimized energy consumption, mild reaction conditions, swift reaction kinetics with accelerated throughput, and universal applicability to dispersed or bulk SWCNTs. The synergy of spectral self‐reporting establishes a paradigm for chemically programmable quantum defect engineering, unlocking scalable quantum light source applications. We hope our work will inspire further innovations and applications in chemically programmed quantum systems.