RF atomic nitrogen plasma molecular beam epitaxy (MBE) was used to deposit gallium nitride (GaN) p-i-n junction photovoltaic detectors on (0001) sapphire. The detectors consisted of a bottom contact layer n-type silicon doped to 5 × 1018 cm−3. The intrinsic layer was undoped and possessed an n-type background carrier concentration of 1 × 1016 cm−3. The top /p-GaN layer was doped with magnesium to give a Hall concentration of 5 × 1017 cm−3. The p-type GaN cathodoluminescence (CL) spectra showed a strong 372 nm emission level in contrast to the 430 nm level observed in MOCVD samples. These layers were fabricated into 1 × 10 element detector arrays using a chlorine-based reactive ion etch (RIE) and refractory metal ohmic contacts. Peak responsivity of 0.11 AAV on detectors without anti-reflection coating were obtained at the GaN bandedge of 360 nm. The ultraviolet (UV) to visible rejection ratio was greater than 103 − 104 and was accredited to the reduction of the yellow defect levels in MBE material. Preliminary results on Al x Ga1−x N detectors with responsivity peaks at 313 and 343 nm are presented as well.