Abstract
Surface ligands are often used to improve perovskite solar cells (PSCs). Here, a series of surface ligands with varying dipole moments are applied at the methylammonium lead iodide (MAPbI3)/C60 interface to vary the energy-level alignment. All investigated surface ligands improve PSC performance, with 4-fluorophenethylammonium iodide (FPEAI) displaying the greatest improvement. Transient absorption and reflectance measurements show similar recombination dynamics in all ligand-treated MAPbI3/C60 bilayer films. Transient photovoltage measurements also show similar recombination lifetimes at similar charge-carrier densities; however, differential capacitance measurements indicate that FPEAI shifts the differential capacitance curve to higher voltages. In situ ultraviolet photoemission spectroscopy measurements show that the interfacial energy gap at the MAPbI3/C60 interface increases from 1.19 eV with phenethylammonium iodide (PEAI) to 1.50 eV with FPEAI, corresponding to the shift of the differential capacitance curve. This increased interfacial energy gap is responsible for the increased open-circuit voltage (VOC) and should be considered in surface ligand selection.
| Original language | English |
|---|---|
| Article number | 101650 |
| Journal | Cell Reports Physical Science |
| Volume | 4 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 15 2023 |
Bibliographical note
Publisher Copyright:© 2023 The Authors
Funding
We acknowledge Thomas Heumüller for sharing helpful design details relevant to the development of our TPV and TPC setup. T.L. and K.R.G. acknowledge funding from the National Science Foundation under award OIA-1929131 . T.L., H.R.A., H.P., and K.R.G. acknowledge funding from the US Department of Energy (DOE), Office of Basic Energy Sciences , under grant DE-SC0018208 for supporting the photoemission spectroscopy measurements and TPV and TPC measurements. S.J. and K.R.G. acknowledge support from the National Science Foundation under cooperative agreement no. 1849213 . The LEIS measurements were enabled by National Science Foundation MRI # 1919845 and performed at Colorado Shared Instrumentation in Nanofabrication and Characterization (COSINC) at the University of Colorado, Boulder. Work at NREL was supported through the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Sciences, within the DOE. The views expressed in the article do not necessarily represent the views of the DOE or the US government. We acknowledge Thomas Heumüller for sharing helpful design details relevant to the development of our TPV and TPC setup. T.L. and K.R.G. acknowledge funding from the National Science Foundation under award OIA-1929131. T.L. H.R.A. H.P. and K.R.G. acknowledge funding from the US Department of Energy (DOE), Office of Basic Energy Sciences, under grant DE-SC0018208 for supporting the photoemission spectroscopy measurements and TPV and TPC measurements. S.J. and K.R.G. acknowledge support from the National Science Foundation under cooperative agreement no. 1849213. The LEIS measurements were enabled by National Science Foundation MRI #1919845 and performed at Colorado Shared Instrumentation in Nanofabrication and Characterization (COSINC) at the University of Colorado, Boulder. Work at NREL was supported through the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Sciences, within the DOE. The views expressed in the article do not necessarily represent the views of the DOE or the US government. T.L. performed PSC device fabrication and film and device characterization, designed and carried out TPV measurements, and prepared the manuscript. R.A.S. performed TR and TA measurements. X.Z. and M.C. helped improve the PSC device fabrications. T.L. and S.J. measured in situ UPS and IPES. Q.J. conducted XRD and SEM measurements. H.R.A. carried out the XPS measurements. H.P. helped with ligand preparation. K.Z. and J.M.L. contributed to the analysis and provided advice. M.C.B. and K.R.G. supervised the study, and K.R.G. helped write the manuscript. M.C.B. K.R.G. and R.A.S. helped revise the manuscript. The manuscript reflects the contributions of all authors. The authors declare no competing interests. We support inclusive, diverse, and equitable conduct of research.
| Funders | Funder number |
|---|---|
| National Science Foundation (NSF) | OIA-1929131, 1919845 |
| Michigan State University-U.S. Department of Energy (MSU-DOE) Plant Research Laboratory | |
| Office of Science Programs | |
| Office of Basic Energy Sciences | 1849213, DE-SC0018208 |
| University of Colorado Boulder | |
| Government of South Australia |
Keywords
- interfacial energetics
- inverted perovskite solar cell
- photoemission spectroscopy
- transient absorbance
- transient photocurrent
- transient photovoltage
- transient reflectance
- ultrafast spectroscopy
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- General Engineering
- General Energy
- General Physics and Astronomy