Mechanistic origins of excitonic properties in 2D perovskites: Implications for exciton engineering

Kameron R. Hansen, Cindy Y. Wong, C. Emma McClure, Blake Romrell, Laura Flannery, Daniel Powell, Kelsey Garden, Alex Berzansky, Michele Eggleston, Daniel J. King, Carter M. Shirley, Matthew C. Beard, Wanyi Nie, André Schleife, John S. Colton, Luisa Whittaker-Brooks

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish (US)
Pages (from-to)3463-3482
Number of pages20
Issue number10
StatePublished - Oct 4 2023


  • 2D semiconductor
  • MAP3: Understanding
  • Wannier exciton
  • band-gap engineering
  • charge-lattice interactions
  • dielectric function
  • electroabsorption
  • halide perovskite
  • phonon screening
  • quantum well
  • superlattice

ASJC Scopus subject areas

  • General Materials Science


Dive into the research topics of 'Mechanistic origins of excitonic properties in 2D perovskites: Implications for exciton engineering'. Together they form a unique fingerprint.

Cite this