title: High Efficiency CdS/CdSe Quantum Dot Sensitized Solar Cells with Two ZnSe Layers.
abstract: CdS/CdSe quantum dot sensitized solar cells (QDSCs) have been intensively investigated; however, most of the reported power conversion efficiency (PCE) is still lower than 7% due to serious charge recombination and a low loading amount of QDs. Therefore, suppressing charge recombination and enhancing light absorption are required to improve the performance of QDSCs. The present study demonstrated successful design and fabrication of QDSCs with a high efficiency of 7.24% based on CdS/CdSe QDs with two ZnSe layers inserted at the interfaces between QDs and TiO2and electrolyte. The effects of two ZnSe layers on the performance of the QDSCs were systematically investigated. The results indicated that the inner ZnSe buffer layer located between QDs and TiO2serves as a seed layer to enhance the subsequent deposition of CdS/CdSe QDs, which leads to higher loading amount and covering ratio of QDs on the TiO2photoanode. The outer ZnSe layer located between QDs and electrolyte behaves as an effective passivation layer, which not only reduces the surface charge recombination, but also enhances the light harvesting.
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.|College of Environmental Science and Engineering, Donghua University , Shanghai 201620, P.R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Huang
authors.affiliation: College of Environmental Science and Engineering, Donghua University , Shanghai 201620, P.R. China.
authors.forename: Lisha
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Juan
authors.initials: J
authors.lastname: Hou
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Hongen
authors.identifier: http://orcid.org/0000-0002-6859-5683
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Donghua University , Shanghai 201620, P.R. China.
authors.forename: Huanli
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Shanglong
authors.initials: S
authors.lastname: Peng
authors.affiliation: College of Environmental Science and Engineering, Donghua University , Shanghai 201620, P.R. China.
authors.forename: Jianshe
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.
authors.forename: Guozhong
authors.identifier: http://orcid.org/0000-0003-1498-4517
authors.initials: G
authors.lastname: Cao
keywords: CdS/CdSe quantum dots; ZnSe buffer layer; ZnSe passivation layer; enhanced quantum dots loading; quantum dot-sensitized solar cell; reduced charge recombination