Brand : Edinburgh Instrument
Model : FLS920
Photoluminescence is a light emitting analysis of any substance such as liquid, solid or powder that absorbs light in electromagnetic radiation. Light is directed onto a sample, where it is absorbed and imparted excess energy into the material in a process called photo-excitation. One way this excess energy can be dissipated by the sample is through the emission of light, or luminescence. Photo-excitation causes electrons within a material to move into permissible excited states. When these electrons return to their equilibrium states, the excess energy is released and may include the emission of light (a radiative process) or may not (a non-radiative process).
The energy of the emitted light (photoluminescence) relates to the difference in energy levels between the two electron states involved in the transition between the excited state and the equilibrium state. Photoluminescence is formally divided into two categories namely fluorescence and phosphorescence, depending on the nature of the excited state. Typical fluorescence lifetime is around 10 ns meanwhile phosphorescence lifetimes are typically in milliseconds to seconds. This equipment also enables to measure fluorescence lifetime using TCSPC technique and anisotropy analysis.
NORHASHIMAH BINTI RAMLI