Multi-color-emissive carbon dots (CDs) are gaining attention due to their unique features, but their limited red emission has restricted their applications. To address this, we explored the emission origins of CDs through concentration-dependent photoluminescence (PL). We synthesized CDs that exhibit blue/red dual-color emission under a single 365 nm excitation. As the concentration increased, the blue emission shifted from 431 to 500 nm, while the red emission around 650 nm changed in intensity without a significant spectral shift. Our spectroscopic analysis, which included varying solvents and pH levels, indicated that interparticle distance is crucial for the dual-emissive behavior of CDs. These CDs show promise for white light-emitting diodes (WLED) and ratiometric pH sensing applications due to their unique PL properties.-Scientific Journal cover design by scapiens

https://pubs.rsc.org/en/content/articlelanding/2020/cp/d0cp02120b#!divAbstract