Polymer Encapsulants Incorporating Light‐Guiding Architectures to Increase Optical Energy Conversion in Solar Cells

The fabrication of a new type of solar cell encapsulation architecture comprising a periodic array of step‐index waveguides is reported. The materials are fabricated through patterning with light in a photoreactive binary blend of crosslinking acrylate and urethane, wherein phase separation induces the spontaneous, directed formation of broadband, cylindrical waveguides. This microstructured material efficiently collects and transmits optical energy over a wide range of entry angles. Silicon solar cells comprising this encapsulation architecture show greater total external quantum efficiencies and enhanced wide‐angle light capture and conversion. This is a rapid, straightforward, and scalable approach to process light‐collecting structures, whereby significant increases in cell performance may be achieved.