White light and colour controlled LEDs

摘要

A light emitting device 300A includes a light source 102 and a wavelength-conversion region 116 optically coupled to the source 102. The wavelength-conversion region comprises a Group IIB Selenide-based phosphor 118 and a thiogallate-based phosphor 119 which convert some of the light emitted by the source 102 at a first wavelength into a second and a third wavelength respectively. The thiogallate-based phosphor 119 may have a structure defined by MNxSy where M is selected from a group including Barium, Calcium, Strontium or Magnesium; N is selected from a group including Aluminium, Gallium and Indium; and x and y are numbers. Other embodiments require only one of the Selenide-based 118 or thiogallate-based 119 phosphors in order to control the colour emitted by the device 300A. The device 300A also includes a reflector cup 322 to increase light emission.