Materials (Nov 2019)

Investigation of AgInS<sub>2</sub>/ZnS Quantum Dots by Magnetic Circular Dichroism Spectroscopy

  • Yulia Gromova,
  • Anastasiia Sokolova,
  • Danil Kurshanov,
  • Ivan Korsakov,
  • Victoria Osipova,
  • Sergei Cherevkov,
  • Aliaksei Dubavik,
  • Vladimir Maslov,
  • Tatiana Perova,
  • Yurii Gun’ko,
  • Alexander Baranov,
  • Anatoly Fedorov

DOI
https://doi.org/10.3390/ma12213616
Journal volume & issue
Vol. 12, no. 21
p. 3616

Abstract

Read online

Over recent years, quantum dots (QDs) based on ternary metal dichalcogenides have attracted a lot of attention due to their unique properties and a range of potential applications. Here, we review the latest studies on the optical properties of AgInS2/ZnS QDs with emphasis on their theoretical modeling, and present our investigations of electronic transitions invisible in unstructured absorption spectra of AgInS2/ZnS QDs. The analysis of the absorption, photoluminescence excitation (PLE), and magnetic circular dichroism (MCD) spectra of hydrophobic and hydrophilic AgInS2/ZnS QDs of different sizes enables us to determine positions of electron transitions in these QDs. We demonstrate that the use of the second derivative of PLE spectra provides more unequivocal data on the position of the energy transitions compared with the second derivative of absorption spectra. Analysis of the MCD spectra reveals that the magnetic field induces energy level mixing in AgInS2/ZnS QDs in contrast to the traditional Cd-based QDs, where MCD is associated only with removing degeneracy of the excited energy level.

Keywords