In this article we describe growth and characterization of Ga(In)NP on GaP(100) substrates. Increasing the nitrogen composition in the GaNP bulk layers from 0.6% to 1.7% shifts the light emission color from yellow-amber to red. The optimal substrate temperature window of 500-520 degrees C for GaNP layers growth was determined from analysis of both structural and optical properties. Incorporation of up to 20% indium into a GaN0.008P0.992 quantum well leads to a redshift of PL peak position and increasing of the photoluminescence intensity by a factor of 12. Ga(In)NP grown on transparent Gal? substrates is considered to be an attractive material system for amber-red light-emitting devices. (c) 2005 American Vacuum Society