Efficiency Enhancement of Quantum Dot Sensitized TiO2/ZnO Nanorod Arrays Solar Cells by Plasmonic Ag Nanoparticles

Haifeng Zhao; Fei Huang; Juan Hou; Zhiyong Liu; Qiang Wu; Haibin Cao; Qun Jing; Shanglong Peng; Guozhong Cao

doi:10.1021/acsami.6b06386

Efficiency Enhancement of Quantum Dot Sensitized TiO₂/ZnO Nanorod Arrays Solar Cells by Plasmonic Ag Nanoparticles

ACS Appl Mater Interfaces. 2016 Oct 12;8(40):26675-26682. doi: 10.1021/acsami.6b06386. Epub 2016 Sep 28.

Authors

Haifeng Zhao, Fei Huang¹, Juan Hou, Zhiyong Liu, Qiang Wu, Haibin Cao, Qun Jing, Shanglong Peng¹, Guozhong Cao¹

Affiliation

¹ Department of Materials and Engineering, University of Washington , Seattle, Washington 98195-2120, United States.

PMID: 27648815
DOI: 10.1021/acsami.6b06386

Abstract

A high efficiency quantum dot sensitized solar cell (QDSC) based on Ag nanoparticles (NPs) decorated TiO₂/ZnO nanorod arrays (NAs) photoelectrode has been constructed. The incorporation of Ag NPs to TiO₂/ZnO NAs photoelectrode not only increases light harvesting efficiency and facilitates exciton dissociation but also decreases surface charge recombination and prolongs electron lifetime, which collectively contribute to improving the J_sc of the CdS/CdSe QDs cosensitized solar cells. The direct contact of Ag NPs with TiO₂ NPs is undergoing Fermi level alignment; thus, the apparent Fermi level is supposed to trigger an upward shift of more negative potential, which results in an increase the V_oc of the QDSCs. As a result, the power conversion efficiency of the QDSCs with Ag NPs decorated TiO₂/ZnO NAs photoelectrode reached 5.92%, which is about 22% enhancement of the efficiency for the solar cells without Ag NPs (4.80%).

Keywords: Ag nanoparticles; TiO2; ZnO nanorod arrays; localized surface plasmon resonance; quantum dot sensitized solar cells.