Electron and hole adducts formed in illuminated InP colloidal quantum dots studied by electron paramagnetic resonance

Olga I. Mićić, Arthur J. Nozik, Efrat Lifshitz, Tijana Rajh, Oleg G. Poluektov, Marion C. Thurnauer

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

An electron paramagnetic resonance (EPR) study of photoexcited colloidal InP quantum dots (QD) shows the formation of electron and hole adducts. An EPR signal at g = 0.58 is assigned to a nonradiative hole trap that does not form immediately upon illumination, but forms only after the illuminated sample ages and becomes stabilized at room temperature; it then becomes permanent at the InP QD surface. This signal completely disappears upon electron injection into the QD from a reducing agent (sodium biphenyl). Light immediately quenches the signal at g = 0.58, and it re-forms reversibly when the light is turned off. A signal at g = 2.055 is assigned to electron surface traps, and it appears in nonetched QD samples; it completely disappears after etching with HF. A signal at g = 2.001 has a very narrow line width and is assigned to delocalized mobile holes that are located in the QD core. A defect model for InP QDs is proposed based on the EPR results reported here plus results from optically detected magnetic resonance experiments reported separately.

Original languageEnglish (US)
Pages (from-to)4390-4395
Number of pages6
JournalJournal of Physical Chemistry B
Volume106
Issue number17
DOIs
StatePublished - May 2 2002
Externally publishedYes

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Electron and hole adducts formed in illuminated InP colloidal quantum dots studied by electron paramagnetic resonance'. Together they form a unique fingerprint.

Cite this