skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

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.

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); FOR
OSTI Identifier:
949467
Report Number(s):
ANL/CHM/JA-41258
Journal ID: ISSN 1089-5647; JPCBFK; TRN: US1003548
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
J. Phys. Chem. B
Additional Journal Information:
Journal Volume: 106; Journal Issue: 17 ; May 2, 2002; Journal ID: ISSN 1089-5647
Country of Publication:
United States
Language:
ENGLISH
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ADDUCTS; BIPHENYL; DEFECTS; ELECTRON SPIN RESONANCE; ELECTRONS; ETCHING; ILLUMINANCE; LINE WIDTHS; MAGNETIC RESONANCE; QUANTUM DOTS; REDUCING AGENTS; SODIUM

Citation Formats

Micic, O I, Nozik, A J, Lifshitz, E, Rajh, T, Poluektov, O G, Thurnauer, M C, Chemistry, NREL,, and Technion-Israel Inst. of Tech. Electron and hole adducts formed in illuminated InP colloidal quantum dots studied by electron paramagnetic resonance.. United States: N. p., 2002. Web. doi:10.1021/jp014180q.
Micic, O I, Nozik, A J, Lifshitz, E, Rajh, T, Poluektov, O G, Thurnauer, M C, Chemistry, NREL,, & Technion-Israel Inst. of Tech. Electron and hole adducts formed in illuminated InP colloidal quantum dots studied by electron paramagnetic resonance.. United States. https://doi.org/10.1021/jp014180q
Micic, O I, Nozik, A J, Lifshitz, E, Rajh, T, Poluektov, O G, Thurnauer, M C, Chemistry, NREL,, and Technion-Israel Inst. of Tech. 2002. "Electron and hole adducts formed in illuminated InP colloidal quantum dots studied by electron paramagnetic resonance.". United States. https://doi.org/10.1021/jp014180q.
@article{osti_949467,
title = {Electron and hole adducts formed in illuminated InP colloidal quantum dots studied by electron paramagnetic resonance.},
author = {Micic, O I and Nozik, A J and Lifshitz, E and Rajh, T and Poluektov, O G and Thurnauer, M C and Chemistry and NREL, and Technion-Israel Inst. of Tech.},
abstractNote = {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.},
doi = {10.1021/jp014180q},
url = {https://www.osti.gov/biblio/949467}, journal = {J. Phys. Chem. B},
issn = {1089-5647},
number = 17 ; May 2, 2002,
volume = 106,
place = {United States},
year = {Thu May 02 00:00:00 EDT 2002},
month = {Thu May 02 00:00:00 EDT 2002}
}