Paramagnetic Point Defects and Charge Carriers in PbS and CdS Nanocrystal Polymer Composites

David J. Keeble; Elizabeth A. Thomsen; Alexandros Stavrinadis; Ifor D. W. Samuel; Jason M. Smith; Andrew A. R. Watt

doi:10.1021/jp9044429

Paramagnetic Point Defects and Charge Carriers in PbS and CdS Nanocrystal Polymer Composites

David J. Keeble, Elizabeth A. Thomsen, Alexandros Stavrinadis, Ifor D. W. Samuel, Jason M. Smith, Andrew A. R. Watt

Research output: Contribution to journal › Article › peer-review

22 Citations (Scopus)

Abstract

Using electron paramagnetic resonance we identify point defects in CdS nanocrystals. A spectrum consistent With Cd vacancies in distorted sites is observed, and evidence for S vacancies is presented. Light-induced paramagnetic states attributed to defects are also detected in PbS nanocrystals. Nanocrystal shallow donor electron states are observed in CdS composites with the Conjugated polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV), and show an increased g-value compared to the bulk, which is Consistent With quantum confinement. Dark state MEH-PPV polarons are observed for composites with small (3.6 nm) CdS nanocrystals.

Original language	English
Pages (from-to)	17306-17312
Number of pages	7
Journal	Journal of Physical Chemistry C
Volume	113
Issue number	40
DOIs	https://doi.org/10.1021/jp9044429
Publication status	Published - 8 Oct 2009

Keywords

LIGHT-EMITTING-DIODES
ELECTRON-SPIN-RESONANCE
QUANTUM DOTS
SOLAR-CELLS
CONDUCTING POLYMER
EPR
NANOPARTICLES
NANORODS
SULFIDE
DONORS

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10.1021/jp9044429

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title = "Paramagnetic Point Defects and Charge Carriers in PbS and CdS Nanocrystal Polymer Composites",

abstract = "Using electron paramagnetic resonance we identify point defects in CdS nanocrystals. A spectrum consistent With Cd vacancies in distorted sites is observed, and evidence for S vacancies is presented. Light-induced paramagnetic states attributed to defects are also detected in PbS nanocrystals. Nanocrystal shallow donor electron states are observed in CdS composites with the Conjugated polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV), and show an increased g-value compared to the bulk, which is Consistent With quantum confinement. Dark state MEH-PPV polarons are observed for composites with small (3.6 nm) CdS nanocrystals.",

keywords = "LIGHT-EMITTING-DIODES, ELECTRON-SPIN-RESONANCE, QUANTUM DOTS, SOLAR-CELLS, CONDUCTING POLYMER, EPR, NANOPARTICLES, NANORODS, SULFIDE, DONORS",

author = "Keeble, {David J.} and Thomsen, {Elizabeth A.} and Alexandros Stavrinadis and Samuel, {Ifor D. W.} and Smith, {Jason M.} and Watt, {Andrew A. R.}",

year = "2009",

month = oct,

day = "8",

doi = "10.1021/jp9044429",

language = "English",

volume = "113",

pages = "17306--17312",

journal = "Journal of Physical Chemistry C",

issn = "1932-7447",

publisher = "American Chemical Society",

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TY - JOUR

T1 - Paramagnetic Point Defects and Charge Carriers in PbS and CdS Nanocrystal Polymer Composites

AU - Keeble, David J.

AU - Thomsen, Elizabeth A.

AU - Stavrinadis, Alexandros

AU - Samuel, Ifor D. W.

AU - Smith, Jason M.

AU - Watt, Andrew A. R.

PY - 2009/10/8

Y1 - 2009/10/8

N2 - Using electron paramagnetic resonance we identify point defects in CdS nanocrystals. A spectrum consistent With Cd vacancies in distorted sites is observed, and evidence for S vacancies is presented. Light-induced paramagnetic states attributed to defects are also detected in PbS nanocrystals. Nanocrystal shallow donor electron states are observed in CdS composites with the Conjugated polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV), and show an increased g-value compared to the bulk, which is Consistent With quantum confinement. Dark state MEH-PPV polarons are observed for composites with small (3.6 nm) CdS nanocrystals.

AB - Using electron paramagnetic resonance we identify point defects in CdS nanocrystals. A spectrum consistent With Cd vacancies in distorted sites is observed, and evidence for S vacancies is presented. Light-induced paramagnetic states attributed to defects are also detected in PbS nanocrystals. Nanocrystal shallow donor electron states are observed in CdS composites with the Conjugated polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV), and show an increased g-value compared to the bulk, which is Consistent With quantum confinement. Dark state MEH-PPV polarons are observed for composites with small (3.6 nm) CdS nanocrystals.

KW - LIGHT-EMITTING-DIODES

KW - ELECTRON-SPIN-RESONANCE

KW - QUANTUM DOTS

KW - SOLAR-CELLS

KW - CONDUCTING POLYMER

KW - EPR

KW - NANOPARTICLES

KW - NANORODS

KW - SULFIDE

KW - DONORS

U2 - 10.1021/jp9044429

DO - 10.1021/jp9044429

M3 - Article

SN - 1932-7447

VL - 113

SP - 17306

EP - 17312

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 40

ER -

Paramagnetic Point Defects and Charge Carriers in PbS and CdS Nanocrystal Polymer Composites

Abstract

Keywords

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