Tricolor Emitting Carbon Dots in ORMOSIL Films Through Surface Tuning
DIPSIKHA BHATTACHARYA1,2, MANISH KUMAR MISHRA1, GOUTAM DE1
1 - Nano-Structured Materials Division, CSIR−Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata
2 - Department of Chemistry, School of Science, Adamas University, Barasat-Barackpore Road, Kolkata
A simple strategy to fabricate carbon dots (CDs) incorporated organically modified silica (ORMOSIL) films exhibiting tunable light emission has been accomplished. First, the green emitting CDs with excitation independent nature and high quantum yields (QYs) were prepared. These CDs after purification were dispersed in ORMOSIL sol and their Photoluminescence wavelengths were tuned to three deep luminescent colors (orange, yellow and green) by simply modifying the pH of the CD-ORMOSIL solution.
It was observed that the functional groups residing on surface of CDs are undergoing chemical modifications with pHs and accordingly the PL emission of CDs systematically changes to orange, yellow and green colors. These luminescent sols can be well-preserved in the dried state to obtain the above tricolor luminescent films on glass. The plausible mechanism behind the rationalization of pH tuning of surface passivated CD-ORMOSIL sols and their incorporation in restrictive film have been explored.
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