Year: 2025
Type: article
Abstract: Electron-hole pairs in semiconductors are essential for solar cells and fast electronic circuitry, but the competition between carrier transport and relaxation into heat limits the efficiency and speed. Here we use ultrafast electron diffraction with terahertz pulse compression to measure the electron-phonon decay rate in single-crystal silicon as a function of laser excitation strength. We find that the excited electrons relax slower into phonons for higher carrier densities. The electron-phonon scattering rate changes in a nonlinear way from 400 fs at ∼ 2 × 10 20 / c m 3 to 1.2 ps at ∼ 4 × 10 20 / c m 3 . These results indicate that a hot electron gas quenches the scattering into phonons in a temperature-dependent way. Ultrafast electronic circuitry of silicon should therefore work faster and provide higher bandwidths at lower carrier densities.
Source: Physical Review Research
Authors: A. B. Swain, J. Kuttruff, J. Vorberger, P. Baum
Institutions: University of Konstanz, Helmholtz-Zentrum Dresden-Rossendorf
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,625
Awards: G2559764746, G4946745191, G5848059424
OpenAlex ID: W4410092842