Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 11, Issue 2, Pages 2243-2253Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.8b17128
Keywords
organic solar cells; N,S-doped carbon quantum dots; ZnO; light-soaking effect; surface passivation
Funding
- National Natural Science Foundation of China [U1710117, 51773224, 11504408, 51473184]
- Shanxi Provincial Key Innovative Research Team in Science and Technology [201605D131045-10]
- Shanxi Provincial Key Research and Development Program [201603D111010]
- Suzhou Science and Technology Project [SYG201735]
- Key Laboratory of Interface Science and Engineering in Advanced Materials opening project (Taiyuan University of Technology), Ministry of Education [KLI-SEAM201502]
Ask authors/readers for more resources
Zinc oxide (ZnO) is one of the most extensively used electron-transporting layers (ETLs) in organic solar cells. However, owing to numerous surface defects and mismatched energy bands with the photoactive layer, light-soaking process is usually required to achieve a high device performance for the ZnO-based cells. Herein, we reported the synthesis of N,S-doped carbon quantum dots (N,S-CQDs) by a simple hydrothermal treatment using ascorbic acid and ammonium persulfate as reagents. As characterized by high-resolution transmission electron microscopy and X-ray diffraction, the synthesized CQDs were found to be 2-7 nm in dimensions, having a graphite-structured core and amorphous carbon on the shell. Fourier transform infrared and X-ray photoelectron spectroscopy analyses confirmed that these CQDs are highly nitrogen- and sulfur-doped, which leads to efficient (with a quantum yield of 33%) downconversion and excitation-dependent photoluminescence character. Application of these N,S-CQDs as surface modifier for ZnO layer in inverted organic solar cells was investigated. Results indicate that the cells with N,S-CQDs-decorated ZnO ETL showed higher power conversion efficiency without S-shaped kink in the current density voltage curves. The performance improvement and the elimination of light-soaking effect for ZnO:N,S-CQDs cells are attributed to the ZnO surface defect passivation by N,S-CQDs, as confirmed by fluorescence spectroscopy and scanning Kelvin probe microscopy. The cells with N,S-CQDs-modified ZnO ETL showed a high power conversion efficiency of 9.31%, which is higher than the reference ZnO cells. The current work provides a feasible way to achieve shell element-doped CQDs for specific application in organic electronic devices.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available