A backlight unit for a LCD can include a TFT array substrate, a UV light source disposed at an edge or bottom of the TFT array substrate, and a layer of transparent fluorescent films formed on the TFT array substrate. The layer of transparent fluorescent films can include a plurality of red transparent fluorescent films, a plurality of green transparent fluorescent films, and a plurality of blue transparent fluorescent films. The layer of transparent fluorescent films can function as a color filter. In some embodiments, a light guide plate and a conventional color filter are omitted from the LCD.