A lighting device provides a spectrally-shifted light output from a light
source. The lighting device includes a semiconductor light emitting
device providing a source light and a first thin-film luminescent
material layer coating a surface of the semiconductor light emitting
device. The first thin-film luminescent material layer includes a
luminescent material that emits an emitted light in response to the
source light. The first thin-film luminescent material layer has a
specific and consistent thickness and specific and consistent density of
luminescent particles. The emitted light includes a first luminescent
material emitted light when the luminescent material completely absorbs
the source light. The emitted light includes a first composite light when
the first luminescent material absorbs less than all of the source light.
The device may further include a second thin-film luminescent layer
coating the first thin-film luminescent layer.