Nitrogen Concentration Dependence on Two-Step Photocurrent Generation in GaNAs/AlGaAs Solar Cells

The two-step photocurrent generation in GaNAs/AlGaAs solar cells with different N concentrations is investigated. By incorporating a higher N concentration, a deep confinement of carriers was achieved. An additional photocurrent is generated by a two-step photo absorption process via the confined energy states. The bias dependence of this two-step photocurrent is discussed.