The growth and radiation response of n+p deep homojunction InP solar cells

InP solar cells grown by metal organic chemical vapor deposition (MOCVD) exhibit a higher beginning of life efficiency (BOL) than InP solar cells grown by thermally diffused junctions (DJ). However, cells grown by MOCVD do not display the nearly complete recovery in photovoltaic (PV) parameters upon annealing that DJ cells do. To investigate the cause of this different behavior the Research Triangle Institute (RTI), contracted by the Naval Research Laboratory, fabricated epitaxial MOCVD InP solar cells with nonuniform dopant profiles grown to mimic the structure of the DJ cell with the goal that these cells would also show the DJ cell´s annealing characteristics. Cells were grown on both ⟨111⟩B and ⟨100⟩ oriented InP substrates to see if this would influence the cell´s radiation resistance. Preliminary results of the effect of 1 MeV electron irradiation on the PV parameters of both kinds of cells are presented