title: Core-shell structured photovoltaic devices based on PbS quantum dots and silicon nanopillar arrays.
abstract: We fabricated three-dimensional silicon nanopillar array (SiNP)-based photovoltaic (PV) devices using PbS quantum dots (QDs) as the hole-transporting layers. The core-shell structured device, which is based on high aspect ratio SiNPs standing on roughed silicon substrates, displays a higher PV performance with a power conversion efficiency (PCE) of 6.53% compared with that of the planar device (2.11%). The enhanced PCE is ascribed to the increased light absorption and the improved charge carrier collections in SiNP-modified silicon surfaces. We also show that, for the core-shell structured device, the thickness of the shell layer plays a critical role in enhancing the PV performance and around five monolayers of QDs are preferred for efficient hole-transporting. Wafer-scale PV devices with a radial PbS/SiNP heterojunction can be fabricated by solution phase techniques at low temperatures, suggesting a facile route to fabricate unique three-dimensional nanostructured devices.
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou, 215123, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.forename: Fute
authors.initials: F
authors.lastname: Zhang
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Lei
authors.forename: Yonglan
authors.initials: Y
authors.lastname: Xu
authors.forename: Shuittong
authors.initials: S
authors.lastname: Lee
authors.forename: Baoquan
authors.initials: B
authors.lastname: Sun
mesh_terms: D007854:Lead / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D045663:Quantum Dots; D012825:Silicon / Q000737:chemistry*; D012993:Solar Energy; D013440:Sulfides / Q000737:chemistry*
chemical_list: D013440:Sulfides; C018391:lead sulfide; D007854:Lead; D012825:Silicon