Biomimetic artificial Si compound eye surface structures with broadband and wide-angle antireflection properties for Si-based optoelectronic applications.
We report the biomimetic artificial silicon (Si) compound eye structures for broadband and wide-angle antireflection by integrating nanostructures (NSs) into periodically patterned microstructures (p-MSs) via thermal dewetting of gold and subsequent dry etching. The truncated cone microstructures with a two-dimensional hexagonal symmetry pattern were fabricated by photolithography and dry etching processes. The desirable shape and density of the nanostructures were obtained by controlled dewetting. The incorporation of p-MSs into the NS/Si surface further reduced the surface total reflectance over a wide wavelength range of 300-1030 nm at near normal incidence, indicating the average reflectance (Ravg) and solar weighted reflectance (RSWR) values of ~ 2.5% and 2%, respectively, compared to the only NSs on the flat Si surface (i.e., Ravg ~ 4.9% and RSWR ~ 4.5%). Additionally, the resulting structure improved the angle-dependent antireflection property due to its relatively omnidirectional shape, which exhibited the Ravg < 4.3% and RSWR < 3.7% in the wavelength region of 300-1100 nm even at a high incident light angle of 70° in the specular reflectance.
Department of Electronics and Radio Engineering, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, Republic of Korea. jsyu@khu.ac.kr.
Jung Woo
JW
Leem
Young Min
YM
Song
Jae Su
JS
Yu
D040761:Biomimetic Materials / Q000737:chemistry*; D004581:Electronics; D006046:Gold / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
D006046:Gold; D012825:Silicon