The 63rd JSAP Spring Meeting, 2016

Presentation information

Oral presentation

3 Optics and Photonics » 3.12 Nanoscale optical science and near-field optics

[19p-S622-1~16] 3.12 Nanoscale optical science and near-field optics

Sat. Mar 19, 2016 2:00 PM - 6:15 PM S622 (S6)

Kenji Imakita(Kobe Univ.), Itsuki Banno(Univ. of Yamanashi)

3:00 PM - 3:15 PM

[19p-S622-5] Control of Photon Statistics from Single Quantum Dots by Interacting with Metal-Coated AFM Tip

Hiroyuki Naiki1, Hiroki Takata1, Norihisa Koizumi1, Sadahiro Masuo1 (1.Kwansei Gakuin Univ.)

Keywords:localized surface plasmon resonance,quantum dot,photon statistics

Semiconductor quantum dots (QDs) have an attractive property of generating multiple excitons. The multiple excitons relaxation is naturally dominated by Auger recombination, that is, most of excitons are non-radiatively decayed. Hence, single QDs can indicate single-photon emissions.
We have demonstrated the multi-photon emission from single QDs with silver nanoparticles and gold cubes by inhibiting the Auger recombination via localized surface plasmon resonance (LSPR) of metal nanostructures. The multiple excitons could radiate faster than Auger recombination by interacting single QDs with the LSPR.
In this work, we controlled the emission photon statistics from single QDs by interacting with silver-coated atomic force microscopy tip (Ag tip). The Ag tip was approached to single QDs on a single nanometer scale by AFM-combined confocal fluorescence microscopy. The correlation of the Ag tip-QD distance and the emission photon statistics was investigated.
The photoluminescence intensity of the single QDs was increased by approaching Ag tip, and then the photoluminescence intensity was decreased by approaching more, however. The lifetime was shortened, and simultaneously the probability of single-photon emission was decreased with reducing on the distance, respectively. From the results, the LSPR of Ag tip firstly enhanced the photoluminescence emission behavior by dominantly interacting with single QDs. However, the quenching by the Ag tip led to the multi-photon emission via multiple exciton recombination by approaching too close.
In the conclusion, we have successfully controlled the single-photon and multi-photon emission from single QDs interacting with Ag tip by adjusting Ag tip-QD distance on a single nanometer scale.