Role of spacer cations and structural distortion in two-dimensional germanium halide perovskites

The elucidation of the structure-property correlation in 2D metal halide perovskite is a key issue to understand the dependence of optical properties on structural distortions and to design novel tailored materials. To extend the actual knowledge on this kind of correlation for lead-free materials,...

Full description

Saved in:
Bibliographic Details
Published in:Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2021-08, Vol.9 (31), p.9899-996
Main Authors: Chiara, Rossella, Morana, Marta, Boiocchi, Massimo, Coduri, Mauro, Striccoli, Marinella, Fracassi, Francesco, Listorti, Andrea, Mahata, Arup, Quadrelli, Paolo, Gaboardi, Mattia, Milanese, Chiara, Bindi, Luca, De Angelis, Filippo, Malavasi, Lorenzo
Format: Article
Language:English
Subjects:
Correlation
Crystallography
Density functional theory
Distortion
Elongation
Germanium
Lead free
Metal halides
Optical properties
Parameters
Perovskites
Tin
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The elucidation of the structure-property correlation in 2D metal halide perovskite is a key issue to understand the dependence of optical properties on structural distortions and to design novel tailored materials. To extend the actual knowledge on this kind of correlation for lead-free materials, here we report four novel 2D germanium bromide perovskites, namely A 2 GeBr 4 with A = phenylethylammonium, PEA, Br-phenylethylammonium, BrPEA, F-phenylethylammonium, FPEA, and benzylammonium BZA. A dependence of the band gap value and emission characteristics in terms of Stokes shift and peak width has been highlighted and correlated with the octahedral distortion parameters. In addition, by comparing the actual results with previous data on analogous Sn- and Pb-based materials, we observed an intrinsic increased distortion induced by germanium, particularly on the octahedral bond elongation and bond angle variance, and less on the Ge-Br-Ge bond angle. The structural and optical investigation, together with density functional theory simulations, clarified the role of different structural distortion parameters on the optical properties for a series of 2D Ge-containing perovskites, thus providing novel clues for the future design of layered lead-free materials. The role of the organic spacer on the properties of Ge-based layered perovskites has been highlighted.
ISSN:2050-7526
2050-7534
DOI:10.1039/d1tc02394b