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A Review of Carbon Dots – A Versatile Carbon Nanomaterial
Published in Swamini Chopra, Kavita Pande, Vincent Shantha Kumar, Jitendra A. Sharma, Novel Applications of Carbon Based Nano-Materials, 2023
Jayanta Sarmah Boruah, Ankita Deb, Jahnabi Gogoi, Kabyashree Phukan, Neelam Gogoi, Devasish Chowdhury
Phosphorescence: Phosphorescence is a spin forbidden process and refers to a radiative transition from the triplet state (T1) to the singlet ground state (S0). The phosphorescence lifetime is, therefore, longer than the fluorescence lifetime. CDs are reported to exhibit phosphorescence, monitored by steady-state PL spectroscopy and time-resolved PL spectroscopy. Deng et al. (2013) synthesized CDs from disodium salt of EDTA (ethylene diamine tetraacetic acid) in polyvinyl alcohol (PVA) by forming a CD-PVA composite. The composite obtained a phosphorescence peak at 500 nm, having a lifetime of 380 ms by exiting the sample with 325 nm. It has been assumed that the phosphorescence originated from the triplet excited states of aromatic carbonyls on the surface of the CDs, wherein the PVA molecules can effectively protect the triplet excited state from being quenched by rigidifying these groups with hydrogen bonding and oxygen. Apart from using in anti-counterfeiting applications, the room-temperature phosphorescent material can also be used in chemical and biological sensing and time-resolved imaging because of the water-soluble and biocompatible nature of the material (Anwar et al. 2019).
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Published in David W. Richerson, William E. Lee, Modern Ceramic Engineering, 2018
David W. Richerson, William E. Lee
Phosphorescence is another important optical property displayed by some ceramic compositions. Phosphorescence is the emission of light resulting from the excitation of the material by the appropriate energy source. Ceramic phosphors are used in fluorescent lights, oscilloscope screens, TV screens, photocopy lamps, and other applications.22
Light Production
Published in Abdul Al-Azzawi, Photonics, 2017
Phosphorescent materials, such as zinc sulfide products have numerous applications in safety signs, luminous watch dials, and military and novelty applications. They can be produced as paints, tapes, ropes, vinyl, plastisol, inks, pigments, and varnishes to fit many applications.
Synthesis, characterization and formation mechanism of Gd2O2S:Pr3+,Ce3+ phosphors by sealed triple-crucible method
Published in Journal of Asian Ceramic Societies, 2020
Xiaotong Sang, Jingbao Lian, Nianchu Wu, Xue Zhang, Jiao He
Phosphorescence or afterglow is related to the capture of energy by various types of traps and the subsequent release of this energy through emission. The persistence is determined by the number, nature and depth of the traps and by the efficiency of the trapping process [26]. Figure 11 shows the decay curve of Gd2O2 S:0.2%Pr3+,Ce3+ phosphor excited by 301 nm UV light. The fluorescence decay curve can be well fitted by a double-exponential function: