Ultrafast dynamics of photo-carriers and judge of the band structures of cation-vacancy-ordered Ga₂Se₃ thin films.

ABSTRACT: Ga₂Se₃ film is fabricated using pulse laser deposition and determined to be in the β phase and to have a direct bandgap of 2.66 eV using absorption and Raman spectra. The ultrafast dynamics measured at 2.67 eV show a strong initial positive peak near zero-delayed time, followed by a fast decay within 1.5 ps into a fully negative dynamic signal. No dynamics occur for photon energies below 2.0 eV. Fully negative ultrafast dynamics are observed for a wide photon-energy range of 2.0-2.48 eV. The excitation-fluence dependent ultrafast dynamics measured at 2.21 eV exhibit fast and slow two-step decaying. A band structure model is proposed to explain all ultrafast dynamic phenomena observed.

SUBMITTER: He Q 

PROVIDER: S-EPMC12496198 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature