NOVELTY - The intermediate band solar cell (100) has a p-n junction having a p-type layer and an n-type layer, with each of the p-type and n-type layers of material having an intermediate band. A contact blocking layer (104) is positioned on an outer surface of the n-type layer that provides electrical isolation of the intermediate band of the p-type and n-type layers by blocking the transport of holes and electrons in the intermediate band.    USE - Dilute group iii-v nitride intermediate band solar cell.    ADVANTAGE - The intermediate band (IBand) only acts as a stepping stone for the absorption of the lower energy photons and hence increases the short circuit current (ISC) of the device, as the IBand of the gallium nitrogen arsenide (GaNAs) absorber layers are isolated and effectively blocking the intermediate band is effectively blocked from contact with neighboring layers.The contact blocking layers are used for improved solar cell performance. The overall quality of the material is improved and material-based defects that could occur from routine usage and testing that could otherwise harm the efficiency of the intermediate band solar cell (IBSC) are reduced, as lattice-matching parameters of the material are improved, as indium (In) is added to layers so to form a gallium indium nitrogen arsenide layer. The overall power conversion efficiency and performance of a IBSC are improved by effectively isolating the IBand using blocking layers, as the open circuit voltage values, and photocurrent generated by increased light absorption through the isolated IBand are increased. Production costs are lowered by considerably simplifying the solar cell design over more complex multijunction solar cells, as a single P-N junction is employed by utilizing IBSC.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the IBSC.    IBSC (100)    Substrate layer (102)    Contact blocking layer (104)    Gallium nitrogen arsenide P-N junction layers (106,108)    Aluminum gallium arsenide layer (110)