Transient photoconductivity and photo-excited carrier dynamics in (Bi1-xInx)2Se3 thin films

Teng Shi, Kateryna Kushnir, Zhengtianye Wang, Stephanie Law, Lyubov Titova

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We use time-resolved THz spectroscopy to study microscopic conductivity and photoinduced carrier dynamics in MBE-grown 100 nm thick (Bi1-xInx)2Se3 thin films with indium concentration varying from x=0 to x=0.5. Both intrinsic and photoinduced conductivity in Bi2Se3 is significantly higher compared to the films with x=0.25 and x=0.50, with carriers that are not constrained by the twin domain boundaries and exhibit high mobility of 1100 cm2/Vs. We find that introducing indium with concentration of x=0.25 and higher, above the threshold for a topological to trivial transition, suppresses both intrinsic and photoinduced conductivity by over an order of magnitude and reduces the lifetime of photoexcited carriers. These findings demonstrate that controlling indium concentration in (Bi1-xInx)2Se3 films provides an avenue to design (Bi1-xInx)2Se3 films with desired properties for high-speed optoelectronic devices.

Original languageEnglish (US)
Title of host publicationUltrafast Phenomena and Nanophotonics XXIV
EditorsMarkus Betz, Abdulhakem Y. Elezzabi
ISBN (Electronic)9781510633193
StatePublished - 2020
EventUltrafast Phenomena and Nanophotonics XXIV 2020 - San Francisco, United States
Duration: Feb 2 2020Feb 4 2020

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceUltrafast Phenomena and Nanophotonics XXIV 2020
Country/TerritoryUnited States
CitySan Francisco

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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