Fig. 1. Electroluminescent (EL) spectra of blue LED with different excitation current values

Fig. 2. Luminescence parameters of blue LED with different excitation current values

Fig. 3. Spectra of blue LED under the conditions of different temperatures and constant excitation current values. (a) Excitation current of 500 mA; (b) excitation current of 1000 mA

Fig. 4. Variations of luminescence parameters of blue LED with temperature at different excitation current values. (a) Excitation current of 500 mA; (b) excitation current of 1000 mA

Fig. 5. Absorption and emission spectra of Ce∶YAG phosphor ceramic at room temperature

Fig. 6. Photoluminescence (PL) spectra of white LED with different excitation current values

Fig. 7. Variations of luminescence parameters of white LED with excitation current values

Fig. 8. PL spectra of white LED under the conditions of different temperatures and constant excitation current values. (a) Excitation current of 500 mA; (b) excitation current of 1000 mA

Fig. 9. Correlated color temperature (CCT) of white LED under different testing conditions. (a) Constant temperature and variable currents testing; (b) constant current and variable temperatures testing