Growth and fabrication of GaNP-based amber light-emitting diodes (LEDs) are reported. A simple p-i-n heterojunction LED structure, emitting at 612 nm was grown directly on a transparent GaP (100) substrate. Current-voltage (I-V) characteristics of 380 mu m X 380 mu m LED chips are comparable to those of conventional AlInGaP-based LEDs, but GaNP-based LEDs exhibit a much higher breakdown voltage. The significant simplicity of a one-step growth process of GaNP-based LEDs is an advantage over etch removing of a GaAs absorbing substrate and wafer bonding to a GaP transparent substrate for conventional AlInGaP-based LEDs. (c) 2006 American Vacuum Society.