Abstract: A light emitting device comprises a plurality of LED chips (“lateral” or “vertical” conducting) operable to generate light of a first wavelength range and a package for housing the chips. The package comprises: a thermally conducting substrate (copper) on which the LED chips are mounted and a cover having a plurality of through-holes in which each hole corresponds to a respective one of the LED chips. The holes are configured such that when the cover is mounted to the substrate each hole in conjunction with the substrate defines a recess in which a respective chip is housed. Each recess is at least partially filled with a mixture of at least one phosphor material and a transparent material. In a device with “lateral” conducting LED chips a PCB is mounted on the substrate and includes a plurality of through-holes which are configured such that each chip is directly mounted to the substrate. For a device with “vertical” conducting LED chips the LED chips are mounted on a diamond like carbon film.