title: Si microwire solar cells: improved efficiency with a conformal SiO2 layer.
abstract: Silicon microwire arrays have attracted considerable attention recently due to the opportunity they present as highly efficient and cost-effective solar cells. In this study, we report on efficient Si microwire array solar cells with areas of 1 cm(2) and Air Mass 1.5 Global conversion efficiencies of up to 10.6%. These solar cells show an open-circuit voltage of 0.56 V, a short-circuit current density of 25.2 mA/cm(2), and a fill factor of 75.2%, with a silicon absorption region that is only 25 μm thick. In particular, the maximum overall efficiency of the champion device is improved from 8.71% to 10.6% by conformally coating the wires with a 200 nm thick SiO2 layer. Optical measurements reveal that the layer reduces reflection significantly over the entire visible range.
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Kwanyong
authors.initials: K
authors.lastname: Seo
authors.forename: Young J
authors.initials: YJ
authors.lastname: Yu
authors.forename: Peter
authors.initials: P
authors.lastname: Duane
authors.forename: Wenqi
authors.initials: W
authors.lastname: Zhu
authors.forename: Hyunsung
authors.initials: H
authors.lastname: Park
authors.forename: Munib
authors.initials: M
authors.lastname: Wober
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Crozier