Random subwavelength structures on glass to improve photovoltaic module performance

Abstract

Glass samples have been processed by a single-step self-masking RIE (Reactive Ion Etching) process to obtain random subwavelength structures (SWSs), which mimic anti-reflective and anti-soiling patterns present in nature. The SWSs fabricated on glass provide an excellent broadband omnidirectional anti-reflective (AR) property (¡1% absolute reflectance) in the spectral region (300–1200) nm due to the graded refractive index that these SWS produce in the air–glass interface, reducing the reflectance. Moreover, these SWSs increase the roughness of the glass surface enhancing its wettability and anti-soiling properties. In order to quantify the performance improvement of photovoltaic devices when using these structured glasses as front cover, commercial PERC (Passivated Emitter and Rear Contact) solar cells have been laminated with these structured glasses using the standard configuration (glass/EVA/Solar Cell/EVA/backsheet) and their electrical parameters such as I–V curve, spectral response, and IAM (Incidence Angle Modifier) factor have characterized.