Light-emitting devices having a semiconductor phosphor layer formed by metalorganic chemical vapor deposition (MOCVD). The semiconductor phosphor layer may be any Group III nitride semiconductor compound that is in-situ doped during MOCVD deposition with one or more dopants effective to act as luminescent centers. The MOCVD deposition conditions required for the formation of these extrinsic luminescent films differ significantly from the MOCVD deposition conditions utilized to deposit intrinsic GaN luminescent films.