Grown junction GaAs solar cells with a thin graded band-gap Al xGa 1− xAs surface layer

Abstract

Liquid phase epitaxial growth techniques were used to fabricate ( n)GaAs:Sn-( p)GaAs:Ge-( p)Al x Ga 1− x As:Ge heterostructure solar cells. Graded band-gap Al x Ga 1− x As layers with thicknesses between 1500 and 2500 Å were prepared by isothermal growth from an undersaturated solution. Spectral response measurements show that the resulting built-in electric field at the surface of the solar cell reduces the surface recombination velocity and improves the collection efficiency.