Large‐area GaN photovoltaic structures withp‐njunctions have been fabricated using atmospheric pressure metalorganic chemical vapor deposition. The photovoltaic devices typically exhibit selective spectral characteristics with two narrow peaks of opposite polarity. This can be related top‐njunction connected back‐to‐back with a Schottky barrier. The shape of the spectral characteristic is dependent on the thickness of then‐ andp‐type regions. The diffusion length of holes in then‐type GaN region, estimated by theoretical modeling of the spectral response shape, was about 0.1 &mgr;m. ©1995 American Institute of Physics.