Home
Resources
Publications
Longer Cations Increase Energetic Disorder in Excitonic 2D Hybrid Perovskites

Longer Cations Increase Energetic Disorder in Excitonic 2D Hybrid Perovskites

Daniel B Straus, Natasha Iotov, Michael R Gau, Qinghua Zhao, Patrick J Carroll, Cherie R Kagan

J Phys Chem Lett. 2019 Mar 21;10(6):1198-1205.

PMID: 30807175

Abstract:

We synthesize and characterize derivatives of the two-dimensional hybrid perovskite (2DHP) phenethylammonium lead iodide ((PEA)2PbI4) in which the para H on the cation is replaced with F, Cl, CH3, or Br. These substitutions increase the length of the cation but leave the cross-sectional area unchanged, resulting in structurally similar PbI42- frameworks with increasing interlayer spacing. Longer cations result in broader, blue-shifted excitonic absorption spectra with reduced or eliminated structure, indicating greater energetic disorder. Photoluminescence spectra are largely invariant and insensitive to cation length, suggesting polaron formation stabilizes a structural and electronic minimum. Temperature-dependent line width analysis reveals excitons couple to a vibration on the organic framework that is weakly sensitive to these cation substitutions, and Raman spectra and electronic structure calculations support the presence of such a cationic mode. Despite carriers being confined to the inorganic framework, the length of the organic cation alters the optical and electronic properties of 2DHPs.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
LS72738	Phenethylammonium iodide			Price

As a specialist in analytical chemical Products, Alfa Chemistry offers consumers a wealth of raw materials and a full range of technologies and services.

QUICK LINKS

HEADQUARTERS

Tel:

Fax:

Email: