LIGHT EMITTING DEVICE COMPRISING A LIGHT SCATTERING MATERIAL LAYER

1 . A light emitting device comprising:

a substrate;

a plurality of LED chips on a front face of the substrate;

a photoluminescence material layer comprising at least one broadband green to red photoluminescence material that covers each of the plurality of LED chips; and

a light scattering layer comprising particles of a light scattering material that covers the photoluminescence material layer and covers at least a part of a back face of the substrate;

wherein the light scattering layer constitutes a light emitting face of the device; and

wherein, when the device is in an off-state, the color of the light emitting face of the device resembles the color of the light scattering material.

2 . The light emitting device of claim 1 , wherein the light scattering material is white in color.

3 . The light emitting device of claim 1 , wherein, in an off-state, the device is substantially the color of the light scattering material.

4 . The light emitting device of claim 1 , wherein the light scattering material is selected from the group consisting of: zinc oxide (ZnO), titanium dioxide (TiO 2 ), barium sulfate (BaSO 4 ), magnesium oxide (MgO), silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium dioxide (ZrO 2 ), and mixtures thereof.

5 . The light emitting device of claim 1 , wherein the photoluminescence material layer comprises a narrowband red photoluminescence material.

6 . The light emitting device of claim 5 , wherein the photoluminescence material layer comprises a single layer comprising the at least one broadband green to red photoluminescence material and the narrowband red photoluminescence material.

7 . The light emitting device of claim 5 , wherein the photoluminescence material layer comprises:

a first layer comprising the narrowband red photoluminescence material that is covers each of the plurality of LED chips; and

a second layer comprising the at least one broadband green to red photoluminescence material that covers the first layer, and

wherein the light scattering layer covers the second layer.

8 . The light emitting device of claim 5 , wherein the narrowband red photoluminescence material is at least one phosphor selected from the group consisting of: K 2 SiF 6 :Mn 4+ , K 2 GeF 6 :Mn 4+ , and K 2 TiF 6 :Mn 4+ .

9 . The light emitting device of claim 1 , wherein the light scattering layer covers the back face of the device.

10 . The light emitting device of claim 1 , wherein the light scattering layer comprises respective light scattering layers constituting the front and back face of the device.

11 . The light emitting device of claim 1 , wherein the substrate comprises a light transmissive substrate.

12 . The light emitting device of claim 1 , wherein there is no photoluminescence material layer on the back face of the substrate.