Year: 2025
Type: preprint
Abstract: Decades of research into size-dependent semiconductor optical gaps have focused on quantum confinement as the dominant mechanism. Emerging reports indicate that lattice strain—intentional or incidental—can impart optical shifts similar or greater in magnitude. Here, we report evidence of optical absorption and photoluminescence spectra of M(1,2,3- triazolate)2 M = Mg, Cr, Mn, Fe, Co, Cu, Zn, Cd nanoparticles that blueshift from bulk values with decreasing particle sizes in a manner that defies explanation by conventional quantum confinement. The phenomenon persists for particle sizes as large as 200 nm, whereas quantum confinement generally ceases beyond 20-30 nm diameters, and follows a weaker dependence on particle radius. Computational simulations and crystallographic analysis suggest this behavior arises from size-dependent changes to metal-linker bonding that manifests in strain values comparable to literature reports of straininduced optical shifts in other classes of materials. Taken together, these results represent one of the few examples of sizedependent strain in crystalline materials and reinforce the emerging view that MOFs become softer materials when isolated as nanoparticles.
Source: ChemRxiv
Authors: Faiqa Khaliq, Ryan Beck, Erik Sevensson Grape, Golnaz Navidi, Miles Griffith, Checkers Marshall, Xiaosong Li, Carl Brozek
Institutions: University of Oregon, University of Washington
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Awards: G3485342083, G6916687956, G7193683647
OpenAlex ID: W4413303101