title: High-performance photoelectrochemical cells from ionic liquid electrolyte in methyl-terminated silicon nanowire arrays.
abstract: Photoelectrochemical (PEC) cells based on silicon nanowire arrays (SiNWs) have, to date, exhibited modest power conversion efficiency (PCE) and suffered serious degradation, though they exhibit advantageous properties of charge-transfer/transport properties at the radial-junction and strong light-trap capabilities. The main challenge for this low-cost PEC cell is the surface photooxidation and photocorrosion of the silicon surface when contacting with the electrolyte. In this report, SiNWs derivatized with covalently attached methyl groups, prepared via a two-step chlorination/methylation procedure, demonstrate excellent stability even in the presence of water. Furthermore, SiNWs PEC cells utilizing a room temperature ion liquid (IL) acting as an electrolyte solvent display neglectable surface oxidation. A PEC cell based on a platinum (Pt) nanodots decorated and methylated (-CH(3)) SiNWs electrode in combination with an IL electrolyte yields a PCE of 6.0% and shows excellent stability under simulated air mass (AM) 1.5 solar spectrum irradiation, while the PCE of a PEC cell based on planar silicon only exhibits 0.003%. The inherent performance of these structures indicates that a -CH(3) (Pt) SiNWs electrode in combination with an IL is a new approach to develop a high-performance and low-cost solar cell.
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Shen
authors.forename: Baoquan
authors.initials: B
authors.lastname: Sun
authors.forename: Feng
authors.initials: F
authors.lastname: Yan
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.forename: Fute
authors.initials: F
authors.lastname: Zhang
authors.forename: Suidong
authors.initials: S
authors.lastname: Wang
authors.forename: Xiulin
authors.initials: X
authors.lastname: Zhu
authors.forename: Shuittong
authors.initials: S
authors.lastname: Lee