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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Disentangling Second Harmonic Generation from Multiphoton Photoluminescence in Halide Perovskites using
Darien J Morrow1, Matthew P Hautzinger1, David P Lafayette1
1Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
The Journal of Physical Chemistry Letters
|July 24, 2020
Summary
Multidimensional harmonic generation definitively measures second harmonic generation (SHG) in Ruddlesden-Popper (RP) halide perovskites. This technique reveals that phenylethylammonium (PEA) and 2-thiophenemethylammonium (TPMA) RP perovskites are SHG-active, unlike n-butylammonium (BA) variants.
Area of Science:
- Materials Science
- Solid-State Physics
- Crystallography
Background:
- Layered two-dimensional Ruddlesden-Popper (RP) halide perovskites exhibit promising optical and ferroelectric properties.
- Second harmonic generation (SHG) is crucial for identifying noncentrosymmetric and ferroelectric materials.
- Multiphoton photoluminescence (mPL) often complicates SHG measurements in perovskites.
Purpose of the Study:
- To establish a definitive method for assessing SHG activity in halide perovskites.
- To clarify the SHG activity of RP perovskites with different spacer cations.
- To overcome the challenge of mPL interference in SHG measurements.
Main Methods:
- Application of multidimensional harmonic generation to perovskite samples.
- Scanning and correlating excitation and emission frequencies.
- Analyzing emission features for a frequency-doubling relationship.
Main Results:
- Multidimensional harmonic generation successfully eliminates mPL interference.
- n-butylammonium (BA) RP perovskites (n=2, 3) were found to be centrosymmetric and SHG-inactive.
- RP perovskites with phenylethylammonium (PEA) and 2-thiophenemethylammonium (TPMA) spacer cations demonstrated SHG activity.
Conclusions:
- Multidimensional harmonic generation is a definitive technique for SHG assessment in halide perovskites.
- The SHG activity of RP perovskites is dependent on the spacer cation.
- This study corrects previous assumptions about the centrosymmetry of BA RP perovskites.
