Concentrated Photovoltaics Using Shape-modified Nanospheres

Light management is one of the main functions of dielectric colloidal nanospheres (NSs), which is beneficial in photonic devices like solar cells (SCs). NSs can direct the broad incident light into several concentrated tighter foci, which results in improved photovoltaic conversion efficiency. Also, the NS arrays can be employed as an effective medium on the SC surface to decrease reflectance and enable better forward scattering. As a result, not only can uniform arrays of NSs on the surface of the SC behave as antireflection coatings, but they also act as micro-lenses, which are considered surface distributed light concentrators that can be utilized in the field of concentrated photovoltaics. The fabrication of NS-based light-trapping structures is cost-effective and simple compared to other options such as vacuum evaporated multilayer antireflection coatings. In this study, experimental results of shape modified NS structures resulting from annealing entail improved light harvesting and better efficiency in Si SCs. The light conversion efficiency of Si solar cells is demonstrated to enhance by more than 19% with shape adjustment of NS arrays.