Photoluminescence
can be divided into two kinds of fluorescence and phosphorescence. The
material, after absorbing the energy of the external light source is
located in the ground state of the electron transition to the excited
state, then if it directly from the energy state to the excited states
in the immediate relief of the lowest vibrational energy state, and
then in order to shine the form back to the ground state, it is called
fluorescence . If through the crossing between systems (intersystem
crossing) is transferred to the electron spin triplet energy state, and
then ease to the lowest vibrational energy state, and then shine in the
form of the release of energy back to the ground state is called
phosphorescence. Different fluorescent ceramic powder issued after
excitation by light of different colors of light, research and
development these new and high-efficiency fluorescent powder, LED is
one of the goals of development. |
