Icspe final
- 1. A.P. Sunitha1 *, Praveen P.2, K. Sandeep3, K . J. Saji2,4,5 1 Dept. of Physics, Govt. Victoria College, Palakkad, Kerala-678001, India 2 International School of Photonics, Cochin University of Science and Technology, Kochi-682022, India 3Dept. of Chemistry, Govt. Victoria College, Palakkad, Kerala-678001, India 4Centre of Excellence in Advanced Materials, Cochin University of Science and Technology, Kochi, 682022, India 5Inter-University Centre for Nanomaterials and Devices, Cochin University of Science and Technology, Kochi, 682022, India, * Corresponding Author: sunivictoria82@gmail.com Upconverting Carbon Quantum Dots for Photovoltaic Applications Abstract •40 ml each of lemon and onion extract was filtered out and subjected to microwave treatment at 200 0 C for 35 min. •The resultant solution was centrifuged at 8000 rpm for 10 min. The clear brown colored solution was filtered out from the bulk remnant. In the present work, the synthesis, characterization and application of CQDs through green route have been discussed. The carbon quantum dots are characterized by dynamic light scattering, transmission electron microscopy, absorption spectroscopy, photoluminescence spectroscopy and found blue luminescent emission. The size was observed to be less than 10 nm. The sample can be modified and applied to bioimaging. •Growth of carbon quantum dots (QDs) from natural extracts •Study of optical transitions in absorbance spectra of carbon QD solution •Study Photon upconversion and downconversion photoluminescence •Study of life time of excited states Experimental:Objectives: Estimation of the size of carbon QDs by DLS and TEM Photoluminescence decay with PH variation Photon upconversion, downconversion photoluminescence and time resolved PL of carbon quantum dots Carbon quantum dots properties Absorption spectra of carbon QDs CQDs were produced by cost effective solution method transition corresponding to QDs were observed in absorption spectra Size of the QDs were estimated by DLS in range less than 10 nm Photon upconversion PL emission peaking at 438 nm and downconversion PL emission peaking around 438 nm Life time of excited state as estimated by time resolved PL is 3.88 ns on three exponential fit Conclusions Acknowledgement: KJS thank Cochin University of Science and Technology for financial support under SMNRI scheme. Future Prospects: •Development CQD based solar cells • Development bioimaging devices Carbon quantum dots Upconversion PL Downconversion PL 400 500 600 300 450 600 Intensity(a.u) Wavelength, nm Excitation 695 nm 400 500 600 2500 5000 7500 10000 Intensity(a.u.) Wavelength, nm Excitation 335 nm 400 500 2500 5000 7500 basic neutral Intensity(a.u.) Wavelength, nm acidic Luminescent Carbon quantum dots can be applied for developing bioimaging devices Upconverting carbon quantum dots are smart materials for energy harvesting, when incorporated in solar cells for exploring the IR window.