Performance Comparison of Top and Bottom Contact Gallium Arsenide (GaAs) Solar Cell.

摘要

We fabricated single-junction solar cell on epitaxially grown n-type gallium arsenide (GaAs) substrate. We used a germanium (Ge)/gold (Au)/nickel (Ni)/Au metal contact from the top side on a highly doped n-type epitaxial layer as well as the bottom side on a n-type GaAs substrate. We observed 10 15% increase in solar cell power when the top contact is used for the n-type GaAs epi layer compared to the bottom side n-type GaAs substrate. Solar cell fill factor, sheet, and shunt resistances are same for both the top and bottom contact type devices. We conclude that to achieve higher power, it is advantageous to use an n-type contact from a highly doped top n epitaxial layer rather than a bottom n-type GaAs substrate.