Patent ID: 6670748
Filing Date: 2003-12-30
Classification: C04B,C09K,F21K,H01L,Y02B

Abstract:
An illumination unit having at least one LED as light source, the LED emitting primary radiation in the range from 300 to 570 nm, this radiation being partially or completely converted into the longer-wave radiation by phosphors which are exposed to the primary radiation of the LED and the structure of which is based on nitrides or derivatives thereof, wherein the conversion takes place with the aid of at least one phosphor which is derived from a cation M and a silicon nitride or a derivative of a nitride which emits with a peak emission wavelength at 430 to 670 nm, the cation being partially replaced by a dopant D, namely Eu2+ or Ce3+, at least one of the divalent metals Ba, Ca, Sr and/or at least one of the trivalent metals Lu, La, Gd, Y being used as cation M, the phosphor originating from one of the following classes:nitrides of the structure MSi3N5, M2Si4N7, M4Si6N11 and M9Si11N23, oxynitrides of the structure M16Si15O6N32 sialons of the structure MSiAl2O3N2, M13Si18Al12O18N36, MSi5Al2ON9 and M3Si5AlON10.