Near-Unity Efficiency Energy Transfer from Colloidal Semiconductor Quantum Wells of CdSe/CdS Nanoplatelets to a Monolayer of MoS2

Nima Taghipour; Pedro Ludwig Hernandez Martinez; Ayberk Ozden; Murat Olutas; Didem Dede; Kivanc Gungor; Onur Erdem; Nihan Kosku Perkgoz; Hilmi Volkan Demir

doi:10.1021/acsnano.8b04119

Near-Unity Efficiency Energy Transfer from Colloidal Semiconductor Quantum Wells of CdSe/CdS Nanoplatelets to a Monolayer of MoS₂

ACS Nano. 2018 Aug 28;12(8):8547-8554. doi: 10.1021/acsnano.8b04119. Epub 2018 Jul 13.

Authors

Nima Taghipour¹, Pedro Ludwig Hernandez Martinez^{1

2}, Ayberk Ozden³, Murat Olutas^{1

4}, Didem Dede¹, Kivanc Gungor¹, Onur Erdem¹, Nihan Kosku Perkgoz⁵, Hilmi Volkan Demir^{1

2}

Affiliations

¹ Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology , Bilkent University , Ankara 06800 , Turkey.
² Luminous! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Materials Sciences, School of Materials Science and Nanotechnology , Nanyang Technological University , Singapore 639798 , Singapore.
³ Department of Materials Science and Engineering, Faculty of Engineering , Anadolu University , 26555 Eskisehir , Turkey.
⁴ Department of Physics , Abant Izzet Baysal University , Bolu 14030 , Turkey.
⁵ Department of Electrical and Electronics Engineering, Faculty of Engineering , Anadolu University , 26555 Eskisehir , Turkey.

PMID: 29965729
DOI: 10.1021/acsnano.8b04119

Abstract

A hybrid structure of the quasi-2D colloidal semiconductor quantum wells assembled with a single layer of 2D transition metal dichalcogenides offers the possibility of highly strong dipole-to-dipole coupling, which may enable extraordinary levels of efficiency in Förster resonance energy transfer (FRET). Here, we show ultrahigh-efficiency FRET from the ensemble thin films of CdSe/CdS nanoplatelets (NPLs) to a MoS₂ monolayer. From time-resolved fluorescence spectroscopy, we observed the suppression of the photoluminescence of the NPLs corresponding to the total rate of energy transfer from ∼0.4 to 268 ns^-1. Using an Al₂O₃ separating layer between CdSe/CdS and MoS₂ with thickness tuned from 5 to 1 nm, we found that FRET takes place 7- to 88-fold faster than the Auger recombination in CdSe-based NPLs. Our measurements reveal that the FRET rate scales down with d^-2 for the donor of CdSe/CdS NPLs and the acceptor of the MoS₂ monolayer, d being the center-to-center distance between this FRET pair. A full electromagnetic model explains the behavior of this d^-2 system. This scaling arises from the delocalization of the dipole fields in the ensemble thin film of the NPLs and full distribution of the electric field across the layer of MoS₂. This d^-2 dependency results in an extraordinarily long Förster radius of ∼33 nm.

Keywords: Auger recombination; FRET; Förster radius; colloidal nanoplatelets; distance dependency; molybdenum disulfide; semiconductor nanocrystals.