title: Nanotexturing process on microtextured surfaces of silicon solar cells by SF6/O2 reactive ion etching.
abstract: We investigated a nanotexturing process on the microtextured surface of single crystalline silicon solar cell by the reactive ion etching process in SF6/O2 mixed gas ambient. P-type Si wafer samples were prepared using a chemical wet etching process to address saw damage removal and achieve microtexturing. The microtextured wafers were further processed for nanotexturing by exposure to reactive ions within a circular tray of wafer carrier containing many small holes for uniform etching. As the dry etching times were increased to 2, 4 and finally to 8 min, surface structures were observed in a transition from nanoholes to nanorods, and a variation in wafer color from dark blue to black. The surface nanostructures showed a lowered photoreflectance and enhanced quantum efficiency within the visible light region with wavelengths of less than 679 nm. The nanohole structure etched for 2 min showed enhanced conversion efficiency when compared to the bare sample; however, the nanorod structure etched for 8 min exhibited the decreased efficiency with a reduced short circuit current, indicating that the surface nanostructural damage with the enlarged nanoperimetric surface area is sensitive to surface passivation from the surface recombination process.
authors.affiliation: Department of Mechanical Engineering and Research Center of Industrial Technology, Chonbuk National University Jeonju 561-756, R. O. Korea.
authors.forename: Hyungyong
authors.initials: H
authors.lastname: Ji
authors.forename: Jaeho
authors.initials: J
authors.lastname: Choi
authors.forename: Gyoungho
authors.initials: G
authors.lastname: Lim
authors.forename: Bhaskar
authors.initials: B
authors.lastname: Parida
authors.forename: Keunjoo
authors.initials: K
authors.lastname: Kim
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Jo
authors.forename: Hong Seub
authors.initials: HS
authors.lastname: Kim