Wrinkeld Polydimethylsiloxane for Enahnced Light Trapping and Anti-Reflection in Flexible Corrugated Silicon Solar Cells

Abstract

Light trapping and anti-reflection schemes serve a key role in reducing light reflection and enhancing absorption within solar cells. Here, we demonstrate the use of polydimethylsiloxane (PDMS) for enhancing light confinement in flexible corrugated c-silicon solar cells. More specifically, corrugated silicon solar cells show a unique textured architecture where islands of silicon are interconnected via interdigitated back contacts. Wrinkled PDMS on the silicon islands in addition to flat PDMS anti-reflective coating within the grooves are shown to improve the power output in flexible corrugated solar cells by almost 9%. Wrinkled PDMS is created during the CO2 laser patterning step applied on a bilayer system with a mismatch in the coefficient of thermal expansion, thus causing linear buckling. It should be noted that, in this case, PDMS serves as both a coating for encapsulating and protecting the cells from the external environmental factors such as water, mechanical shock, etc., in addition to a material for reducing light reflection.