| abstract |
A color tunable light-emitting device is provided which comprises a first light-emitting element, a second light-emitting element, an active light transformative element disposed between the first light-emitting element and the second light-emitting element; and at least one light transmissive element, wherein the first and second light-emitting elements emit light at different wavelengths. Active light transformative elements which may be employed are illustrated by electrochromic elements, photochromic elements, and thermochromic elements. |