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Updated: Nov 30, 2025

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Quantifying Exciton Heterogeneities in Mixed-Phase Organometal Halide Multiple Quantum Wells via Stark Spectroscopy
Eric Amerling1, Sangita Baniya2, Evan Lafalce2
1Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States.
Abstract:
Solution-processable two-dimensional (2D) organic-inorganic hybrid perovskite (OIHP) quantum wells naturally self-assemble through weak van der Waals forces. In this study, we investigate the structural and optoelectronic properties of 2D-layered butylammonium (C4H9NH3+, BA+) methylammonium (CH3NH3+, MA) lead iodide, (BA)2(MA)PbI3 quantum wells with varying n from 1 to 4. Through conventional structural characterization, (BA)2(MA)PbI3 thin films showcase high-quality phase (n) purity. However, while investigating the optoelectronic properties, it is clear that these van der Waals heterostructures consist of multiple quantum well thicknesses coexisting within a single thin film. We utilized electroabsorption spectroscopy and Liptay theory to develop an analytical tool capable of deconvoluting the excitonic features that arise from different quantum well thicknesses (n) in (BA)2(MA)PbI3 thin films. To obtain a quantitative assessment of exciton heterogeneities within a thin film comprising multiple quantum well structures, exciton resonances quantified by absorption spectroscopy were modeled as Gaussian features to yield various theory-generated electroabsorption spectra, which were then fit to our experimental electroabsorption features. In addition to identifying the quantum well heterostructures present within a thin film, this novel analytical tool provides powerful insights into the exact exciton composition and can be utilized to analyze the optoelectronic properties of many other mixed-phase quantum well heterostructures beyond those formed by OIHPs. Our findings may help in designing more efficient and reproducible light-emitting diodes based on 2D mixed-phase metal-organic multiple quantum wells.
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