The disclosure provides a solar cell design featuring p-or-n type GaAs with alternating p-n junction regions on the back-surface of the cell, opposite incident solar irradiance. Various layers of p-or-n type GaAs are interfaced together to collect charge carriers, and a thin layer of AlGaAS is applied to the front and back surfaces to prevent recombination of charge carriers. In some embodiments, the layered an doped structure generally provides an AlGaAs window layer of about 20 nm doped to about 4X(10(18)) cm(-3), a GaAs absorption layer of about 2000 nm doped to about 4X(10(17)) cm(-3), q GaAs emitter layer of about 150 nm and doped to 4X(10(18)) cm(-3), an AlGaAs heterojunction layer of about 40 nm doped to about 3X(10(18)), and a GaAs emitter contact layer of about 20 nm doped to about 1X(10(19) cm(-3). Additionally, AlGaAs BSF layer and GaAs BSF -contact layers each have a depth of about 20 nm and are doped to about 4X(10(18)) cm(-3) and 1X(10(19)) cm(-3) respectively. The emitter layer, heterojunction layer, and emitter-contact layer are doped to a conductivity type opposite the absorption layer.