Patent ID: 8455898

Claim:
A lighting device comprising: a light source, the light source having a source refractive index; a first luminescent layer disposed on top of the light source, the first luminescent layer having a first effective refractive index, the first luminescent layer comprising a first quantum dots composition dispersed in a first matrix material, the first effective refractive index being equal to or less than the source refractive index; a second luminescent layer disposed on top of the first luminescent layer, the second luminescent layer having a second effective refractive index, the second luminescent layer comprising a second quantum dots composition dispersed in a second matrix material, the second effective refractive index being less than the first effective refractive index; and an oxide layer disposed on top of the second luminescent layer, an effective refractive index of the oxide layer is less than the second effective refractive index of the second luminescent layer.