Forward and reverse bias dark current characteristics ofn+pmesa diodes and solar cells fabricated from metalorganic chemical vapor deposition grown Ga0.5In0.5P have been examined, and dark current behavior has been correlated with Ga0.5In0.5P solar cell conversion efficiency. Dependencies of dominant dark currents on voltage, temperature, and doping density were found to be consistent with recombination theory. Recombination dark current with an ideality factor ofA=1.9–2.1 was dominant in the voltage range of ∼0.5 to 1.5 V and ∼0.8 to 1.2 V for devices with ap‐base doping density of ∼1016and 1017cm−3, respectively. Reverse current‐voltage‐temperature measurements identified two dominant deep levels at 0.10 and ∼0.45 eV relative to either the valence‐ or conduction‐band minimum. The carrier recombination was found to occur through these deep level centers in then+pjunction.