The incorporation of nitrogen into GaInAs/GaAs heterostructures has received intense interest recently due to the large negative bowing parameter of the resultant alloy. This change in the band gap for GaInAsN makes it useful for near-infrared optoelectronic devices on the GaAs substrate. However. the effect of adding nitrogen into GaInAs is an important issue in the use of these alloys. This article focuses on the growth of GaInNAs/GaAs alloys for use in photodiodes. Under our growth conditions, we show that the incorporation of nitrogen into GaAs and Ga0.8In0.2As is linear with nitrogen in the growth chemistry up to approximately 3.5%. Photodiodes using GaNAs absorption regions show low dark currents and high quantum efficiencies with nitrogen values up to 1.75%.