title: Improving polymer/nanocrystal hybrid solar cell performance via tuning ligand orientation at CdSe quantum dot surface.
abstract: Achieving superior solar cell performance based on the colloidal nanocrystals remains challenging due to their complex surface composition. Much attention has been devoted to the development of effective surface modification strategies to enhance electronic coupling between the nanocrystals to promote charge carrier transport. Herein, we aim to attach benzenedithiol ligands onto the surface of CdSe nanocrystals in the "face-on" geometry to minimize the nanocrystal-nanocrystal or polymer-nanocrystal distance. Furthermore, the "electroactive" π-orbitals of the benzenedithiol are expected to further enhance the electronic coupling, which facilitates charge carrier dissociation and transport. The electron mobility of CdSe QD films was improved 20 times by tuning the ligand orientation, and high performance poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT):CdSe nanocrystal hybrid solar cells were also achieved, showing a highest power conversion efficiency of 4.18%. This research could open up a new pathway to improve further the performance of colloidal nanocrystal based solar cells.
authors.affiliation: State Key Laboratory of Silicon Materials, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University , Hangzhou 310027, People's Republic of China.
authors.forename: Weifei
authors.initials: W
authors.lastname: Fu
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ruisong
authors.initials: R
authors.lastname: Ma
authors.forename: Lijian
authors.initials: L
authors.lastname: Zuo
authors.forename: Jiangquan
authors.initials: J
authors.lastname: Mai
authors.forename: Tsz-Ki
authors.initials: TK
authors.lastname: Lau
authors.forename: Shixuan
authors.initials: S
authors.lastname: Du
authors.forename: Xinhui
authors.initials: X
authors.lastname: Lu
authors.forename: Minmin
authors.initials: M
authors.lastname: Shi
authors.forename: Hanying
authors.initials: H
authors.lastname: Li
authors.forename: Hongzheng
authors.initials: H
authors.lastname: Chen
keywords: charge transport; electronic coupling; exciton dissociation; hybrid solar cell; ligand orientation