분야
pptx2.Applications
-LED
-Plasma Display
-Various Phosphors
Scintillatior
Nanostructured Phosphors
Quantum Cutting Phosphors
Upconversion Phosphors
-Solar Cells
Inorganic phosphor materials
“Classical” inorganic phosphors usually consist of a host lattice with activator ions doped into it in small concentrations, typically a few mole percent or less.
Host lattice & Activator ion
1st type : weak interaction (Ln3+)
2nd type: strong interaction ( Mn2+, Eu2+, Ce3+, Pb2+,Sb3+, Ce3+, MoO42-, NbO43-)
Activator (+ Sensitizer) Electronic Configuration
Eu2+: 1s 22s 22p6 3s23p6 4s23d104p65s 2 4d105p66s2 4f5 5d
Host (band absorption )~ semiconductor material
The probability for an excited electron to lose energy by
generating lattice vibration :1012 to 1013s-1
The probability for light emission is at most 109s-1.
At finite temperature, the electron state oscillates around the
equilibrium position along the configurational coordinate curve
up to the thermal energy of kT.
At relatively high temperature, a nonradiative relaxation process
the transition probability per unit time, N :
By letting W by the luminescence probability, the luminescence efficiency h can by expressed as:
Incompletely filled 4 f shell
4 f orbital shielded from surroundings by the filled 5s2 &5p6 orbital
small influence of the host lattice to optical transition
