Journal article
Continuously tunable negative pressure for engineering high-symmetry nanocrystalline phases
Proceedings of the National Academy of Sciences - PNAS, v 121(46), e2413942121
12 Nov 2024
PMID: 39508762
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
In this work, the phenomenon of strain induced by a mismatch in thermal expansion coefficients between a thin film and its substrate is harnessed in a new context, replacing the canonical planar support with a three-dimensional (3-D), nanoconfining scaffold in which we embed a material of interest. In this manner, we demonstrate a general approach to exert a continuously tunable, triaxial, tensile strain, defying the Poisson ratio of the embedded material and achieving the exotic condition of “negative pressure.” This approach is hypothetically generalizable to materials of low modulus and high thermal expansion coefficient, and we use it here to achieve negative pressure in perovskite-phase CsPbI 3 embedded within the cylindrical pores of anodic aluminum oxide membranes. Through controlled thermal hysteresis, the perovskite crystal structure can be continuously tuned toward higher symmetry when confined in a scaffold with pore size <40 nm, in contrast with the symmetry-reducing action of any other mechanical perturbation. We use this effect to control the octahedral rotation angle that is critical to the remarkable photovoltaic attributes of halide perovskites. Under hundreds of megapascals of apparent negative pressure, the bandgap tunability is observed to follow the same quantitative trend observed for hydrostatic positive pressure, exploring the negative pressure region and demonstrating the relative dominance of bond stretching effects over average octahedral rotation angle on electronic structure. This study reveals and quantifies the structural and electronic consequences of 3D tensile strain present by design and provides a framework for understanding adventitious strain present in all nanocomposite materials.
Metrics
Details
- Title
- Continuously tunable negative pressure for engineering high-symmetry nanocrystalline phases
- Creators
- Arkita Chakrabarti - Drexel UniversityRamchandra Gawas - Drexel UniversityCraig L. Johnson - CharacterAaron T. Fafarman - Drexel University
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, v 121(46), e2413942121
- Publisher
- NATL ACAD SCIENCES
- Number of pages
- 8
- Grant note
- NSF CAREER Award DMR: 1847952
A.C. and A.T.F. were supported by the NSF CAREER Award DMR# 1847952. SEM and XRD analyses were performed using instruments in the Materials Characterization Core at Drexel University. Transmission XRD measurements were performed by Sujit Ghosh at the beamline at National Synchrotron Light Source II at Brookhaven National Laboratory (28-ID-2) . Steady-state photo-luminescence measurements were performed in Prof. Cherie Kagan's lab at The University of Pennsylvania. We thank Prof. Steven May for his valuable input on perovskite symmetry and XRD interpretation.
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Office of Research (and Innovation); Chemical and Biological Engineering; Chemistry
- Web of Science ID
- WOS:001360805000002
- Scopus ID
- 2-s2.0-85209170769
- Other Identifier
- 991021961115704721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Materials Science, Multidisciplinary