Characterization of light absorption in thin-film silicon with periodic nanohole arrays

• Published in: Optics Express
• Main Author: Yahaya N.A.; Yamada N.; Kotaki Y.; Nakayama T.
• Format: Article
• Language: English
• Published: Optical Society of American (OSA) 2013
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875172888&doi=10.1364%2fOE.21.005924&partnerID=40&md5=07d9188732a2d673716b88c330c9e84f

Light absorption in thin-film nanostructured monocrystalline silicon (c-Si) in a glass/Ag(0.2 μm)/c-Si(1 μm) stack is characterized using simulations and measurements. Nanohole (NH) arrays designed for a practical thin-film solar cell configuration experimentally exhibit a significant improvement of the light absorption in the 1-μm ultrathin c-Si layer that exceeds the theoretical Yablonovitch limit in the long wavelength range. Fabricated square-lattice and hexagonal NH arrays give relative improvements of 65 and 70%, respectively, in the total absorption compared to a nonpatterned stack. The effect of an indium-tin-oxide (ITO) coating is also simulated, and an empty NH configuration gives the lowest ITO parasitic absorption. © 2013 Optical Society of America.