@article{8d5df8b3b97e43b6a9ea3483ec90252f,
title = "Mechanistic origins of excitonic properties in 2D perovskites: Implications for exciton engineering",
abstract = "As the field of 2D halide perovskites (HPs) matures, state-of-the-art techniques to measure important properties, such as the band gap (Eg) and exciton binding energy (Eb), continue to produce inconsistent values. Here, we tackle this long-standing problem by obtaining direct measurements of Eg and Eb for 31 unique HP structures. The Eb values are lower than in previous literature reports and lower than expected from standard theory that assumes excitons are screened by optical-frequency dielectric constants. These low Eb values are shown to be a consequence of unique screening effects, such as superlattice screening and phonon screening. We find a strikingly strong correlation between Eb and Eg and provide design principles to a priori tune Eg and Eb to their optimal values. As such, this work offers a blueprint for Eg-Eb engineering of low-dimensional semiconductors as an even more useful replacement for simply band-gap engineering.",
keywords = "2D semiconductor, MAP3: Understanding, Wannier exciton, band-gap engineering, charge-lattice interactions, dielectric function, electroabsorption, halide perovskite, phonon screening, quantum well, superlattice",
author = "Hansen, {Kameron R.} and Wong, {Cindy Y.} and McClure, {C. Emma} and Blake Romrell and Laura Flannery and Daniel Powell and Kelsey Garden and Alex Berzansky and Michele Eggleston and King, {Daniel J.} and Shirley, {Carter M.} and Beard, {Matthew C.} and Wanyi Nie and Andr{\'e} Schleife and Colton, {John S.} and Luisa Whittaker-Brooks",
note = "This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under award DE-SC0019041. K.R.H. acknowledges support from the National Science Foundation through a graduate research fellowship (grant 1747505). L.W.-B. acknowledges support from the Sloan Foundation through an Alfred P. Sloan Research Fellowship in Chemistry. C.Y.W. and A.S. acknowledge support from the National Science Foundation under grant 1922758. Support and resources from the Center for High Performance Computing at the University of Utah are acknowledged. This work made use of the Illinois Campus Cluster, a computing resource that is operated by the Illinois Campus Cluster Program (ICCP) in conjunction with the National Center for Supercomputing Applications (NCSA) and that is supported by funds from the University of Illinois at Urbana-Champaign. This work was performed in part at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the US Department of Energy's NNSA under contract 89233218CNA000001. M.E. was supported by the NSF REU program, grant 2051129. C.E.M. B.R. D.J.K. and C.M.S. were supported in full or in part by the BYU Department of Physics and Astronomy and BYU College of Physical and Mathematical Sciences. Conceptualization, K.R.H.; methodology, K.R.H.; investigation, K.R.H. C.Y.W. A.S. C.E.M. B.R. L.F. D.P. K.G. A.B. M.E. D.J.K. C.M.S. J.S.C. and L.W.-B.; writing – original draft, K.R.H.; writing – review & editing, K.R.H. and J.S.C.; funding acquisition, L.W.B. K.R.H. J.S.C. and A.S.; resources, L.W.B. J.S.C. and A.S.; supervision, L.W.B. J.S.C. M.C.B. and A.S. The authors declare no competing interests. This work was supported by the US Department of Energy , Office of Basic Energy Sciences , Division of Materials Sciences and Engineering under award DE-SC0019041 . K.R.H. acknowledges support from the National Science Foundation through a graduate research fellowship (grant 1747505 ). L.W.-B. acknowledges support from the Sloan Foundation through an Alfred P. Sloan Research Fellowship in Chemistry. C.Y.W. and A.S. acknowledge support from the National Science Foundation under grant 1922758 . Support and resources from the Center for High Performance Computing at the University of Utah are acknowledged . This work made use of the Illinois Campus Cluster, a computing resource that is operated by the Illinois Campus Cluster Program ( ICCP ) in conjunction with the National Center for Supercomputing Applications ( NCSA ) and that is supported by funds from the University of Illinois at Urbana-Champaign . This work was performed in part at the Center for Integrated Nanotechnologies , an Office of Science User Facility operated for the US Department of Energy ( DOE ) Office of Science. Los Alamos National Laboratory , an affirmative action equal opportunity employer, is managed by Triad National Security , LLC for the US Department of Energy{\textquoteright}s NNSA under contract 89233218CNA000001 . M.E. was supported by the NSF REU program, grant 2051129 . C.E.M., B.R., D.J.K., and C.M.S. were supported in full or in part by the BYU Department of Physics and Astronomy and BYU College of Physical and Mathematical Sciences .",
year = "2023",
month = oct,
day = "4",
doi = "10.1016/j.matt.2023.07.004",
language = "English (US)",
volume = "6",
pages = "3463--3482",
journal = "Matter",
issn = "2590-2393",
publisher = "Cell Press",
number = "10",
}