Cosensitized Quantum Dot Solar Cells with Conversion Efficiency over 12

Wei Wang; Wenliang Feng; Jun Du; Weinan Xue; Linlin Zhang; Leilei Zhao; Yan Li; Xinhua Zhong

doi:10.1002/adma.201705746

Cosensitized Quantum Dot Solar Cells with Conversion Efficiency over 12

Adv Mater. 2018 Mar;30(11). doi: 10.1002/adma.201705746. Epub 2018 Jan 23.

Authors

Wei Wang¹, Wenliang Feng¹, Jun Du¹, Weinan Xue¹, Linlin Zhang¹, Leilei Zhao¹, Yan Li¹, Xinhua Zhong²

Affiliations

¹ Shanghai Key Laboratory of Functional Materials Chemistry, Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China.
² College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China.

PMID: 29359826
DOI: 10.1002/adma.201705746

Abstract

The improvement of sunlight utilization is a fundamental approach for the construction of high-efficiency quantum-dot-based solar cells (QDSCs). To boost light harvesting, cosensitized photoanodes are fabricated in this work by a sequential deposition of presynthesized Zn-Cu-In-Se (ZCISe) and CdSe quantum dots (QDs) on mesoporous TiO₂ films via the control of the interactions between QDs and TiO₂ films using 3-mercaptopropionic acid bifunctional linkers. By the synergistic effect of ZCISe-alloyed QDs with a wide light absorption range and CdSe QDs with a high extinction coefficient, the incident photon-to-electron conversion efficiency is significantly improved over single QD-based QDSCs. It is found that the performance of cosensitized photoanodes can be optimized by adjusting the size of CdSe QDs introduced. In combination with titanium mesh supported mesoporous carbon as a counterelectrode and a modified polysulfide solution as an electrolyte, a champion power conversion efficiency up to 12.75% (V_oc = 0.752 V, J_sc = 27.39 mA cm^-2 , FF = 0.619) is achieved, which is, as far as it is known, the highest efficiency for liquid-junction QD-based solar cells reported.

Keywords: cosensitized photoanodes; high-efficiency solar cells; quantum dot solar cells.