Fluorescence is the light emitted by matter after absorbing light or other electromagnetic radiation. When light is irradiated to some atoms, the energy of light makes some electrons around the nucleus from the original energy level to a higher energy level, that is, from the ground state to the first excited single or second excited singlet states. The first excited single or second excited singlet states are unstable, so the ground state will be restored. When the electron is recovered from the first excited single state to the ground state, the energy will be released in the form of light, that is, to produce fluorescence.
Excitation and emission spectra are standard measurements in fluorescence spectroscopy. In a typical fluorescence excitation spectrum measurement the excitation wavelength is varied across a region, while in a fluorescence emission spectrum measurement the excitation wavelength is fixed and measured by recording the emission spectra resulting from a range of excitation wavelengths and combining them all together. After correction, the relative intensity of fluorescence at different emission wavelengths was obtained.
Applications
Materials science (semiconductor materials PLE/PL)
•Reflection, Absorption and Quantum Yield Measurements of Phosphor Powders
•Fluorescence Upconversion
•Display technique, OLED
•Carbon nanotubes
•Biology (chlorophyll and carotenoid testing)
•Biomedical (fluorescence diagnosis of malignant disease)
•Environment monitoring
Fluorescence spectrum analysis
Fluorescence spectrum can provide more information, such as excitation spectrum, emission spectrum, quantum yield, fluorescence lifetime,