Femtosecond time-resolved hot carrier energy distributions of photoexcited semiconductor quantum dots

2012 ◽  
Vol 525 (1-2) ◽  
pp. 43-48 ◽  
Author(s):  
Chi-Hung Chuang ◽  
Xiaobo Chen ◽  
Clemens Burda
Science ◽  
2020 ◽  
pp. eabb3457 ◽  
Author(s):  
Harsha Reddy ◽  
Kun Wang ◽  
Zhaxylyk Kudyshev ◽  
Linxiao Zhu ◽  
Shen Yan ◽  
...  

Hot-carriers in plasmonic nanostructures, generated via plasmon decay, play key roles in applications like photocatalysis and in photodetectors that circumvent band-gap limitations. However, direct experimental quantification of steady-state energy distributions of hot-carriers in nanostructures has so far been lacking. We present transport measurements from single-molecule junctions, created by trapping suitably chosen single molecules between an ultra-thin gold film supporting surface plasmon polaritons and a scanning probe tip, that can provide quantification of plasmonic hot-carrier distributions. Our results show that Landau damping is the dominant physical mechanism of hot-carrier generation in nanoscale systems with strong confinement. The technique developed in this work will enable quantification of plasmonic hot-carrier distributions in nanophotonic and plasmonic devices.


2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Eduard I. Zenkevich ◽  
Thomas Blaudeck ◽  
Alexander Milekhin ◽  
Christian von Borczyskowski

We review recent experimental work to utilize the size dependence of the luminescence quenching of colloidal semiconductor quantum dots induced by functionalized porphyrin molecules attached to the surface to describe a photoluminescence (PL) quenching process which is different from usual models of charge transfer (CT) or Foerster resonant energy transfer (FRET). Steady-state and picosecond time-resolved measurements were carried out for nanocomposites based on colloidal CdSe/ZnS and CdSe quantum dots (QDs) of various sizes and surfacely attached tetra-mesopyridyl-substituted porphyrin molecules (“Quantum Dot-Porphyrin” nanocomposites), in toluene at 295 K. It was found that the major part of the observed strong quenching of QD PL in “QD-Porphyrin” nanocomposites can neither be assigned to FRET nor to photoinduced charge transfer between the QD and the chromophore. This PL quenching depends on QD size and shell and is stronger for smaller quantum dots: QD PL quenching rate constants scale inversely with the QD diameter. Based on the comparison of experimental data and quantum mechanical calculations, it has been concluded that QD PL quenching in “QD-Porphyrin” nanocomposites can be understood in terms of a tunneling of the electron (of the excited electron-hole pair) followed by a (self-) localization of the electron or formation of trap states. The major contribution to PL quenching is found to be proportional to the calculated quantum-confined exciton wave function at the QD surface. Our findings highlight that single functionalized molecules can be considered as one of the probes for the complex interface physics and dynamics of colloidal semiconductor QD.


2010 ◽  
Vol 81 (7) ◽  
Author(s):  
Julia Kabuss ◽  
Stefan Werner ◽  
Axel Hoffmann ◽  
Peter Hildebrandt ◽  
Andreas Knorr ◽  
...  

2018 ◽  
Vol 232 (9-11) ◽  
pp. 1513-1526 ◽  
Author(s):  
Dzmitry Melnikau ◽  
Thomas Hendel ◽  
Pavel A. Linkov ◽  
Pavel S. Samokhvalov ◽  
Igor R. Nabiev ◽  
...  

Abstract An understanding of the mechanisms of energy transfer and conversion on the nanoscale is one of the key requirements for an implementation of highly efficient photonic nanodevices based on hybrid organic/inorganic nanomaterials. In this work we conduct steady-state and time resolved optical studies of the emission properties of an ensembles and single semiconductor quantum dots and attached organic dye molecules. We revealed that the luminescence intensity of a hybrid structure does not follow the blinking behavior of quantum dots. We also demonstrated an efficient single photon generation from single hybrid nanostructures which involves an energy transfer from donor to acceptor as main excitation source.


2007 ◽  
Vol 75 (3) ◽  
Author(s):  
A. F. van Driel ◽  
I. S. Nikolaev ◽  
P. Vergeer ◽  
P. Lodahl ◽  
D. Vanmaekelbergh ◽  
...  

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