Carrier confinement and bond softening in photoexcited bismuth films
Name
PhysRevB.92.184302.pdf
Size
521.2 KB
Format
Adobe PDF
Checksum (MD5)
efa927fe672099562104543c3c865a3a
Author(s)
Shin, Taeho
Wolfson, Johanna W.
Kandyla, Maria
Teitelbaum, Samuel Welch
Nelson, Keith Adam
Date Issued
November 2015
Journal
Physical Review B
Publisher
American Physical Society
Citation
Shin, Taeho, Johanna W. Wolfson, Samuel W. Teitelbaum, Maria Kandyla, and Keith A. Nelson. “Carrier Confinement and Bond Softening in Photoexcited Bismuth Films.” Physical Review B 92, no. 18 (November 2015). © 2015 American Physical Society
Version
Final published version
Abstract
Femtosecond pump-probe spectroscopy of bismuth thin films has revealed strong dependencies of reflectivity and phonon frequency on film thickness in the range of 25−40 nm. The reflectivity variations are ascribed to distinct electronic structures originating from strongly varying electronic temperatures and proximity of the film thickness to the optical penetration depth of visible light. The phonon frequency is redshifted by an amount that increases with decreasing film thickness under the same excitation fluence, indicating carrier density-dependent bond softening that increases due to suppressed diffusion of carriers away from the photoexcited region in thin films. The results have significant implications for nonthermal melting of bismuth as well as lattice heating due to inelastic electron-phonon scattering.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PhysRevB.92.184302
