title: Core-shell silicon nanowire solar cells.
abstract: Silicon nanowires can enhance broadband optical absorption and reduce radial carrier collection distances in solar cell devices. Arrays of disordered nanowires grown by vapor-liquid-solid method are attractive because they can be grown on low-cost substrates such as glass, and are large area compatible. Here, we experimentally demonstrate that an array of disordered silicon nanowires surrounded by a thin transparent conductive oxide has both low diffuse and specular reflection with total values as low as < 4% over a broad wavelength range of 400 nm < λ < 650 nm. These anti-reflective properties together with enhanced infrared absorption in the core-shell nanowire facilitates enhancement in external quantum efficiency using two different active shell materials: amorphous silicon and nanocrystalline silicon. As a result, the core-shell nanowire device exhibits a short-circuit current enhancement of 15% with an amorphous Si shell and 26% with a nanocrystalline Si shell compared to their corresponding planar devices.
authors.affiliation: Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada. mmadachi@alumni.uwaterloo.ca
authors.forename: M M
authors.initials: MM
authors.lastname: Adachi
authors.forename: M P
authors.initials: MP
authors.lastname: Anantram
authors.forename: K S
authors.initials: KS
authors.lastname: Karim
mesh_terms: D000535:Aluminum / Q000737:chemistry; D011211:Electric Power Supplies; D008854:Microscopy, Electron; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D012825:Silicon / Q000737:chemistry*; D012993:Solar Energy; D013472:Sunlight; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D000535:Aluminum; D015034:Zinc Oxide; D012825:Silicon