Abstract
The deployment of perovskite solar cells will rely on further progress in the operating and ambient stability of active layers and interfaces within these materials. Low-dimensional perovskites, also known as perovskite quantum wells (PQWs), utilize organic ligands to protect the perovskite lattice from degradation and offer to improve device stability; combining 2D and 3D perovskites in heterostructures has been shown to take advantage of the high efficiency of the majority 3D active layers and combine it with the improved stability of a thin 2D top layer. Prior PQWs have relied on relatively weak interwell van der Waals bonding between hydrophobic organic moieties of the ligands. Here we instead use the ligand 4-vinylbenzylammonium to form well-ordered PQWs atop a 3D perovskite layer. The ligand's vinyl group is activated using UV light which photochemically forms new covalent bonds among PQWs. UV-cross-linked 2D/3D devices show improved operational stability as well as improved long-term dark stability in air: They retain 90% of their initial efficiency after 2300 h of dark aging compared to a retention of 20% of performance in the case of 3D films. The UV-cross-linked PQWs and 2D/3D interfaces reduce device hysteresis and improve the open-circuit voltages to values up to 1.20 V, resulting in more efficient devices (PCE of up to 20.4%). This work highlights the exploitation of the chemical reactivity of PQW ligands to tailor the molecular properties of PQW interfaces for improved stability and performance in 2D/3D perovskite photovoltaics.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 14180-14189 |
| Number of pages | 10 |
| Journal | Journal of the American Chemical Society |
| Volume | 141 |
| Issue number | 36 |
| DOIs | |
| State | Published - Sep 11 2019 |
Funding
This publication is based on work supported by the United States Department of the Navy, Office of Naval Research (Grant Award N00014-17-1-2524). A.H.P. was supported by the Canada Graduate Scholarships program from the Natural Sciences and Engineering Research Council of Canada (NSERC). Synchrotron measurements were performed at the HXMA beamline at the Canadian Light Source (CLS). The authors thank Dr. C. Y. Kim at the CLS for technical assistance and scientific guidance during in situ GIWAXS measurements and O. Ouellette for helpful discussions. The CLS is funded by NSERC, the Canadian Institutes of Health Research, Canada Foundation for Innovation, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. This publication is based on work supported by the United States Department of the Navy, Office of Naval Research (Grant Award N00014-17-1-2524). A.H.P. was supported by the Canada Graduate Scholarships program from the Natural Sciences and Engineering Research Council of Canada (NSERC). Synchrotron measurements were performed at the HXMA beamline at the Canadian Light Source (CLS)
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Biochemistry
- Colloid and Surface Chemistry