Self-doped colloidal semiconductor nanocrystals with intraband transitions in steady state

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)


The tunable bandgap energy has been recognized as a prominent feature of the colloidal semiconductor nanocrystal, also called the colloidal quantum dot (CQD). Due to the broken degeneracy caused by the quantum confinement effect, the electronic states of the conduction band (CB) are separated by a few hundred meV. The electronic transition occurring in the conduction band is called the intraband transition and has been regarded as a fast electron relaxation process that cannot be readily observed under steady state. However, recent progress in the studies of intraband transitions allowed the observation of the mid-IR intraband transition in steady state and ambient condition, providing a pathway to exploit the mid-IR electronic transition for various optoelectronic applications. The observation of the steady state intraband transitions has been possible due to the electron filling of the lowest electronic state (1Se) of the conduction band in the semiconductor nanocrystal. Specifically, the nanocrystals are “self-doped” with electrons through chemical synthesis-that is, without the need of adding heterogeneous impurity or applying an electrical potential. In this feature article, we summarize the recent advances in the study on intraband electronic transitions along with the interesting findings on the magnetic and electronic properties of the self-doped colloidal metal chalcogenide semiconductor nanocrystals. The mid-IR intraband transitions of non-toxic nanocrystals, which exclude the toxic mercury and cadmium constituents, are also highlighted, which hold promise for safer applications utilizing the higher quantum states of nanocrystals.

Original languageEnglish
Pages (from-to)8435-8445
Number of pages11
JournalChemical Communications
Issue number61
Publication statusPublished - 2018

Bibliographical note

Funding Information:
This work is supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, & Future Planning (NRF-2016R1C1B2013416).

Publisher Copyright:
© The Royal Society of Chemistry.

ASJC Scopus subject areas

  • Catalysis
  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • General Chemistry
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry


Dive into the research topics of 'Self-doped colloidal semiconductor nanocrystals with intraband transitions in steady state'. Together they form a unique fingerprint.

Cite this