Enhancement of the Anti-Stokes Fluorescence of Hollow Spherical Carbon Nitride Nanostructures by High Intensity Green Laser

• Published in: Nanomaterials (Basel, Switzerland) Vol. 11; no. 10; p. 2529
• Main Authors: Zinin, Pavel V., Acosta-Maeda, Tayro E., Misra, Anupam K., Sharma, Shiv K.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 28.09.2021; MDPI
• Subjects: anti-Stokes; Carbon; Carbon nitride; Fluorescence; g-C3N4; Lasers; Low level; Nanoparticles; Optical properties; Pulsed lasers; Quantum dots; Radiation; s-C3N4
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano11102529

Fluorescence spectra of graphitic (g-C3N4) and spherical (s-C3N4) modifications of carbon nitride were measured as a function of green pulsed (6 ns-pulse) laser intensity. It was found that the intensity of the laser increases the maximum of the fluorescence shifts towards the anti-Stokes side of the fluorescence for s-C3N4 spherical nanoparticles. This phenomenon was not observed for g-C3N4 particles. The maximum of the anti-Stokes fluorescence in s-C3N4 nanoparticles was observed at 480 nm. The ratio of the intensity of the anti-Stokes peak (centered at 480 nm) to that of the Stokes peak (centered at 582 nm) was measured to be I484/582 = 6.4 × 10−3 at a low level of intensity (5 mW) of a green pulsed laser, whereas it rose to I484/582 = 2.27 with a high level of laser intensity (1500 mW).