An efficient light-harvesting scheme using SiO ₂ nanorods for InGaN multiple quantum well solar cells

SiO ₂ nanorod arrays (NRAs) are fabricated on InGaN-based multiple quantum well (MQW) solar cells using self-assembled Ag nanoparticles as the etching mask and subsequent reactive ion etching. The SiO ₂ NRAs effectively suppress the undesired surface reflections over the wavelengths from 330 to 570 nm, which is attributed to the light-trapping effect and the improved mismatch of refractive index at the air/MQW device interface. Under the air mass 1.5 global illumination, the conversion efficiency of the solar cell is enhanced by ∼21% largely due to increased short-circuit current from 0.71 to 0.76 mA/cm ². The enhanced device performances by the optical absorption improvement are supported by the simulation analysis as well.