Temperature dependence of the band gap of Si 28:P at very low temperatures measured via time-resolved optical spectroscopy

authored by
E. Sauter, N. V. Abrosimov, J. Hübner, M. Oestreich
Abstract

We measure the temperature dependence of the indirect band gap of isotopically purified Si28:P in the regime from 0.1 K to 3 K by high-resolution absorption spectroscopy of the donor bound exciton transition. The measurements increase the up-to-date precision of the temperature-dependent band gap change by more than one order of magnitude and reveal a T4 dependence which is about a factor of two less than observed in previous measurements. Such a T4 dependence is predicted by theory, but the absolute values differ between our experiment and the most up-to-date calculations by a factor of 30, corroborating that the electron-phonon interaction at low temperatures is still not correctly included into theory. What is more, the ability of such very high-precision band-gap measurements facilitates the use of time- and spatially resolved Si28:P absorption as a contactless, local thermometer and electric field sensor with a demonstrated time resolution of milliseconds.

Organisation(s)
Institute of Solid State Physics
External Organisation(s)
Leibniz Institute for Crystal Growth (IKZ)
Type
Article
Journal
Physical Review Research
Volume
5
No. of pages
10
ISSN
2643-1564
Publication date
15.03.2023
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
General Physics and Astronomy
Electronic version(s)
https://doi.org/10.1103/PhysRevResearch.5.013182 (Access: Open)