Enhanced electron extraction capability of polymer solar cells via modifying the cathode buffer layer with inorganic quantum dots

Authors

Zhiqi Li, Jilin University
Shujun Li, Jilin University
Zhihui Zhang, Jilin University
Xinyuan Zhang, Jilin University
Jingfeng Li, Jilin University
Chunyu Liu, Jilin University
Liang Shen, University of Nebraska-LincolnFollow
Wenbin Guo, Jilin UniversityFollow
Shengping Ruan, Jilin UniversityFollow

Date of this Version

2016

Citation

Phys. Chem. Chem. Phys., 2016, 18, 11435-11442

DOI: 10.1039/c6cp00989a

Comments

Copyright © 2016 Royal Society of Chemistry. Used by permission.

Abstract

Enhanced performance of polymer solar cells (PSCs) based on the blend of poly[N-9"-hepta-decanyl- 2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT):[6,6]-phenyl-C₇₀-butyric acid methyl ester (PC₇₁BM) is demonstrated by titanium dioxide (TiO₂) interface modification via CuInS₂/ZnS quantum dots (CZdots). Devices with a TiO₂/CZdots composite buffer layer exhibit both a high shortcircuit current density (J_sc) and fill factor (FF), leading to a power conversion efficiency (PCE) up to 7.01%. The charge transport recombination mechanisms are investigated by an impedance behavior model, which indicates that TiO₂ interfacial modification results in not only increasing the electron extraction but also reducing impedance. This study provides an important and beneficial approach to develop high efficiency PSCs.