The hydrogen plasma passivation effects of MOCVD-grown GaAs solar cell on S
i substrate have been studied in detail. To get a more reproducible increas
e of conversion efficiency and test the thermal stability of the plasma-exp
osed GaAs/Si solar cell, both the plasma exposure and post-passivation anne
aling conditions were optimized. Annealing the H-2 plasma passivated GaAs/S
i solar cell at 450 degreesC in AsH3/H-2 ambient seems a very essential par
ameter to restore the carrier concentration, especially, without losing the
beneficial effects of H incorporation into GaAs on Si. For the H-2 plasma
passivated GaAs/Si solar cell, a highest conversion efficiency of 18.3% was
obtained compared with that of the as-grown cell (16.6%) due to the H pass
ivation effects on nonradiative recombination centers, which increased the
minority carrier lifetime. (C) 2001 Elsevier Science B,V. All rights reserv
ed.