A dilute Group III-V nitride solar cell is provided for use in a multijunction solar cell having a p-n junction formed by p-type and n-type layers of dilute Group III-V nitride material, such as GaNAs. Blocking layers of a group III-V ternary alloy are formed on opposing surfaces of the p-n junction to improve the electron and hole collection efficiency of the p-n junction by preventing the flow of electrons and holes, respectively, into the adjacent layers of the multijunction solar cell in certain directions. The III-V nitride solar cell is current matched to other solar cells of the multijunction solar cell. The III-V nitride solar cell may possess a bandgap of approximately 1.0 eV to serve as one junction of the multijunction solar cell. The p-type and n-type layers may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.
STATEMENT OF GOVERNMENTAL INTEREST
 The invention described and claimed herein was made in part utilizing funds supplied by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The government has certain rights in this invention.