title: A CdSe thin film: a versatile buffer layer for improving the performance of TiO2 nanorod array:PbS quantum dot solar cells.
abstract: To fully utilize the multiple exciton generation effects in quantum dots and improve the overall efficiency of the corresponding photovoltaic devices, nanostructuralizing the electron conducting layer turns out to be a feasible strategy. Herein, PbS quantum dot solar cells were fabricated on the basis of morphologically optimized TiO2 nanorod arrays. By inserting a thin layer of CdSe quantum dots into the interface of TiO2 and PbS, a dramatic enhancement in the power conversion efficiency from 4.2% to 5.2% was realized and the resulting efficiency is one of the highest values for quantum dot solar cells based on nanostructuralized buffer layers. The constructed double heterojunction with a cascade type-II energy level alignment is beneficial for promoting photogenerated charge separation and reducing charge recombination, thereby responsible for the performance improvement, as revealed by steady-state analyses as well as ultra-fast photoluminescence and photovoltage decays. Thus this paper provides a good buffer layer to the community of quantum dot solar cells.
authors.affiliation: Key Laboratory of Photovoltaic Materials, Department of Physics and Electronics, Henan University, Kaifeng 475004, PR China. wfzhang@henu.edu.cn.
authors.forename: Furui
authors.initials: F
authors.lastname: Tan
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Wang
authors.forename: Shengchun
authors.initials: S
authors.lastname: Qu
authors.forename: Dawei
authors.initials: D
authors.lastname: Cao
authors.forename: Kong
authors.initials: K
authors.lastname: Liu
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Jiang
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Shan
authors.initials: S
authors.lastname: Pang
authors.forename: Weifeng
authors.initials: W
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Lei
authors.forename: Zhanguo
authors.initials: Z
authors.lastname: Wang