Illumination unit having at least one LED as light source

The invention is based on an illumination unit having at least one LED as light source, in accordance with the preamble of claim 1. It is in particular an LED which emits in the visible or white region and is based on an LED which emits primarily UV. An illumination unit having at least one LED as light source, the LED emitting primary radiation in the range from 300 to 430 nm, this radiation being completely converted into longer-wave radiation by phosphors which are exposed to the primary radiation of the LED, in which unit the conversion takes place at least with the aid of a phosphor which emits green with a peak emission wavelength at 495 to 540 nm and which originates from the class of the Ce-activated sialons, the sialon corresponding to the formula MSiAlON:Ce, where M=Ca individually or in combination with Sr, with q=0 to 2.5 and p=0.5 to 3.