Download file (1.24 MB)
Download as zip (1.2 MB)

Collection

Citation

Description:

We report on the observation of Fermi-edge singularity in the optical absorption and emission spectra of high-quality degenerate Ga-doped ZnO (GZO) films from cryogenic to room temperature, as well as on the related stimulated emission under femtosecond laser pulse excitation. When the photogenerated electron-hole pair density np reaches a threshold, which is as low as np ≈ 1019 cm−3 at room temperature, the emission from
the Fermi edge shows a transition from a spontaneous to a stimulated regime, accompanied by a blueshift in the emission maximum. Further increase in the excitation fluence not only leads to a substantial increase in emission intensity, but it also results in broad and redshifted spectra, accompanied by the shortening of decay times. The resulting stimulated emission can be interpreted in terms of the emission of a population-inverted electron-hole plasma (EHP) in the weakly excited degenerated GZO. The observed low-threshold EHP stimulated emission is consistent with the calculated gain spectra based on a quantum many-body theory.

Rights:

• In Copyright
  

  ©2024 American Physical Society

Keyword: Many-body, ZnO, Luminescence, Absorption, Excitons

Date published: 2024-02-02

Publisher: American Physical Society (APS)

Journal:

• Physical Review B (ISSN: 1550235X) vol. 109 issue. 7 075302

Funding:

Manuscript type: Author's version (Accepted manuscript)

MDR DOI: https://doi.org/10.48505/nims.4765

First published URL: https://doi.org/10.1103/physrevb.109.075302

Related item:

Other identifier(s):

Contact agent:

Updated at: 2024-09-21 12:30:20 +0900

Published on MDR: 2024-09-21 12:30:21 +0900