Illumination devices and methods of making same are disclosed. In one embodiment, a display device includes a light modulating array and a light guide configured to receive light into at least one edge of the light guide. The light guide can be characterized by a first refractive index. The display device can also include a light turning layer disposed such that the light guide is at least partially between the turning layer and the array. The turning layer can comprise an inorganic material characterized by a second refractive index that is substantially the same as the first refractive index.