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Published on: October 9, 2012
Voltage controlled photoluminescence blinking in CdSe nano-particles
Horng-Shyang Chen1, Tao-Hsiang Chung, Ming-Chou Lin
1Department of Materials Science, National University of Tainan, Tainan, Taiwan, ROC.
Optics Express
|January 4, 2011
Summary
Voltage-controlled photoluminescence blinking in Cadmium Selenide nanoparticles (CdSe NPs) is achieved via electrical bias. This method offers a simple way to control blinking intensity and intervals in NP clusters.
Area of Science:
- Materials Science
- Nanotechnology
- Optoelectronics
Background:
- Photoluminescence (PL) blinking in semiconductor nanoparticles is a common phenomenon.
- Controlling PL blinking is crucial for applications in quantum information and sensing.
- Existing methods for controlling PL blinking can be complex.
Purpose of the Study:
- To investigate voltage-controlled photoluminescence blinking in Cadmium Selenide nanoparticles (CdSe NPs).
- To understand the underlying mechanisms of voltage-induced PL blinking.
- To explore the potential for controlling PL blinking behavior through electrical bias.
Main Methods:
- Fabrication of CdSe NPs sandwiched between p-type silicon and a gold electrode.
- Application of bias voltage across the electrodes to control PL blinking.
- Analysis of PL intensity and blinking intervals under varying electrical bias and excitation power.
Main Results:
- Photoluminescence blinking in CdSe NPs can be effectively controlled by applied bias voltage.
- Luminescence diminishes below a threshold voltage or with weak photoexcitation.
- A circuit model involving charge tunneling, Fowler-Nordheim (F-N) emission, and charging explains the observed blinking.
- NP clusters exhibit significantly higher blinking intensity than isolated NPs due to collective recombination.
Conclusions:
- Voltage control offers a straightforward method for modulating PL blinking in CdSe NPs.
- The study elucidates the role of electron emission and hole accumulation in PL blinking.
- Collective effects in NP clusters enhance blinking intensity, suggesting potential for improved optoelectronic devices.
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