It is believed that the effectual scattering by earth-abundant Al nanoparticles in combination with photoelectric conversion-efficient GaAs material may help for cost-effective solar cells. Al nanoparticles of various radii embedded at different depths in a Ta2O5-coated GaAs semiconductor have been studied by finite-difference time-domain method for their influence towards spectral absorption rate and photocurrent in GaAs solar cells. The calculated spectral absorption rate and photocurrent show a significant enhancement at the optimal depth for a particular radius of Al nanoparticles, which is explained on the basis of surface plasmon resonance. Al nanoparticles of radius 80 nm embedded just below the antireflection layer of Ta2O5 result a maximum spectral absorption rate of 0.95 that leads to a photocurrent of 30.43 mA/cm(2).