Design and fabrication of nano-pyramid GaAs solar cell

We demonstrate a genetic method to fabricate large-area nano-structure III-V solar cells with conformal epitaxial growth on pre-patterned substrate. The design, simulation, fabrication, and characterization of a nano-structure gallium arsenide (GaAs) solar cell device are presented. The optical simulation illustrates that the nano-pyramid array is able to suppress the reflection and enhance the absorption in a wide spectrum range. The IV characterization shows that the short circuit current of the nano-pyramid GaAs solar cell with 200 nm thick junction is as high as 18.5 mA/cm², which is more than triple of the planar cell. Our results suggest this nano-structure thin film absorber could significantly reduce epitaxial growth cost and increase yield, thus provides a pathway towards high-efficiency and low-cost solar cells.