Appropriate green phosphor of SrSi_2O_2N_2:Eu^2+,Mn^2+ for AC LEDs

Abstract

An AC (alternating current) LED exhibited the advantages of a low drive current, low static electricity, lack of a need for a rectifier, and high extraction efficiency. The input operating voltage of an AC LED is around 80V, and its operating frequency is 120 Hz or less. When the voltage is converted, a time gap of 1/120 s (10 ms), called dead time, is generated. This time gap is closely related to the scintillation phenomenon. Therefore, AC LEDs that have a phosphor composition, whose half-life composition can compensate for dead time that is generated during the voltage conversion, are sought to solve the problem of scintillation. The object of this work is to provide a phosphor SrSi(2)O(2)N(2):Eu(2+),Mn(2+) for AC LEDs, in which the dead time that is generated during the voltage conversion is compensated for by the half-life of the phosphor.