Backlight apparatus

A backlight apparatus, comprising:

• a wavelength-converting device, comprising:
• a transparent upper barrier film;
• a transparent lower barrier film;
• a first spacer layer, being bonded on the transparent lower barrier film, and having a plurality of first hollowed regions;
• a filling material, covering the plurality of first hollowed regions;
• and
• a plurality of first quantum dots, uniformly distributed in the filling material covering each first hollowed region;
• and
• a light source, comprising:
• a circuit board, disposed beneath the transparent lower barrier film;
• and
• a plurality of semiconductor light-emitting devices, wherein each first hollowed region corresponds to at least one semiconductor light-emitting device, each semiconductor light-emitting device is electrically bonded on the circuit board, and locates beneath the corresponding first hollowed region, each semiconductor light-emitting device emits a first color light passing through the filling material covering the corresponding first hollowed region;
• wherein the first quantum dots distributed in the filling material covering each fist hollowed region absorb a first portion of the first color light passing through said filling material, and convert the absorbed first portion of the first color light into a second color light, the second color light is blended with other portion of the first color light into a third color light propagating toward the transparent upper barrier film.