Design principles of nanostructured window solar cells

Nanostructures in III-V solar cells have been widely investigated. Due to the enhancement in photon absorption, higher short-circuit current has been achieved in a number of previous reports. However, many of the nanostructured solar cells suffer from low open circuit voltage and low fill factor, which result from poor junction quality and high non-radiative recombination. Such problems can be resolved by utilizing both a nanostructured III-V window layer and planar p-n junction. In this work, we demonstrate the design and optimization of nanostructured window solar cells through a set of carefully designed experiments. A systematic study based on device fabrication, characterization and simulation is presented. This work shows that reducing absorption and minority carrier loss inside the nanostructured window are key to further improve the performance of nanostructured window solar cells.