Optimal Solar Cell Efficiency of Radial p-n Junction GaAs/AlGaAs Core-Shell Nanowire Arrays

29th European Photovoltaic Solar Energy Conference and Exhibition; 229-231
The effects of intrinsic light trapping or sunlight concentration in nanowire array solar cells comprising of optimally engineered radial p-n junction GaAs/AlxGa1-xAs core-shell nanowires is maximized for optimal solar cell efficiency by optimizing the pitch length of the nanowire array and angles of incidence of the sun-rays. Results reveal that the unique property of core-shell nanowires in decoupling light absorption and carrier collection, along with the exceptionally low optical reflection and strong light trapping, enable radial p-n junction core-shell nanowire array to achieve solar cell efficiencies as high as more than 35% (i.e., exceeding the Shockley-Queisser limit) when illuminated by the one-sun AM1.5G solar spectrum. Such high solar cell efficiencies are the result of the intrinsic sunlight concentration effect in nanowire array solar cell.