Electric field-induced emission enhancement and modulation in individual CdSe nanowires.
ACS Nano
; 6(10): 9133-40, 2012 Oct 23.
Article
em En
| MEDLINE
| ID: mdl-22978316
ABSTRACT
CdSe nanowires show reversible emission intensity enhancements when subjected to electric field strengths ranging from 5 to 22 MV/m. Under alternating positive and negative biases, emission intensity modulation depths of 14 ± 7% are observed. Individual wires are studied by placing them in parallel plate capacitor-like structures and monitoring their emission intensities via single nanostructure microscopy. Observed emission sensitivities are rationalized by the field-induced modulation of carrier detrapping rates from NW defect sites responsible for nonradiative relaxation processes. The exclusion of these states from subsequent photophysics leads to observed photoluminescence quantum yield enhancements. We quantitatively explain the phenomenon by developing a kinetic model to account for field-induced variations of carrier detrapping rates. The observed phenomenon allows direct visualization of trap state behavior in individual CdSe nanowires and represents a first step toward developing new optical techniques that can probe defects in low-dimensional materials.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos de Selênio
/
Compostos de Cádmio
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Nanoestruturas
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Modelos Químicos
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article