(183ap) Simple and Scalable Nanofabrication of Biomimetic Broadband Anti-Reflection Coatings on Silicon Wafers
Millions of years before people began to fabricate functional nanostructures, biological systems were using nanometer-scale architectures to produce unique functionalities. Some nocturnal moths use hexagonal arrays of subwavelength nipples as anti-reflection (AR) coatings to reduce reflection from their compound eyes for the purpose of night camouflage. Similar periodic arrays of nanopillars have also been observed on the wings of cicada to render superhydrophobic surfaces for self-cleaning functionality. Inspired by these natural nanostructures, we have developed a simple and scalable maskless reactive ion etching technique for fabricating self-cleaning, broadband AR coatings on both single- and multi-crystalline silicon wafers. The resulting subwavelength-structured AR coatings exhibit significantly improved broadband anti-reflection properties than traditional dielectric AR coatings, and show superhydrophobic surface states, promising for applications ranging from highly efficient solar cells and photodetectors to self-cleaning flat-panel displays.