Optical reflectance reduction of textured silicon surfaces coated with an antireflective thin film

摘要: Abstract Solar cells and optical detection devices often incorporate surface texturing antireflective (AR) thin films to reduce reflection enhance absorption. Using micromachining techniques, three different silicon surfaces were fabricated, optically characterized, analyzed relative their ability reflectance. The fabricated consisted of: randomly sized spaced pyramids (RSSPs), deep vertical-wall grooves (DVWGs), porous (PS). Three regions of the spectrum investigated: visible (500 ≤ λ 900 nm), near-infrared (1.25 2.5 μm), mid-infrared (2.5 12.5 μm). A highly-polished, single-crystal wafer was used as a reference surface. RSSP reduced reflectance by more than 69% across entire measured spectrum. DVWG 85% in region, 34% range, 14% over wavelengths. “Thin” (pore depths less 1 μm) “thick” greater 5 PS investigated. manifested 91% reduction 7% 53% To further properties textured 1.53 ± 0.03 μm thick yttrium oxide AR film deposited on samples. AR-coated sample most significant improvement compared sample. Specifically, Ravc = 0.277 with Rσ 0.04, yielded 0.024 0.017.