AlGaAs/Si dual-junction solar cell.
(a) Cross-sectional schematic diagram of the fabricated AlGaAs/Si dual-junction solar cell. The thickness and doping concentration of each layer are indicated. The abbreviation BSF stands for back surface field. (b) Cross-sectional scanning electron microscope image of the solar cell. Inset shows the light I–V and power-voltage characteristics of the solar cell under a 600 nm-peaked halogen white light source of a one-sun intensity (100 mW cm−2).