Color Tunability and Stability of Silicate Phosphor for UV-Pumped White LEDs

White-light-emitting diodes (LEDs) are fabricated by using 375 nm emissive GaN chip with Sr 3 MgSi 2 O 8 :Eu 2 + (blue and yellow) or Sr 3 MgSi 2 O 8 :Eu 2 + , Mn 2 + (blue, yellow, and red). The white lights from cold to warm color are actualized by controlling the mole fractions of Eu 2 + and Mn 2 + ions in Sr 3 MgSi 2 O 8 . Color tuning is based on the energy transfer from blue emission to yellow absorption, and from blue emission to red absorption due to spectral overlap between them. The energy transfers can be confirmed by faster decay time of the blue emission band. Our white LEDs show warm white light (3600 K), excellent color rendering index (95%), and higher color stability to variation of forward-bias voltage in comparison with a commercial white YAG:Ce 3 + -based diode.