Electrical Tuning of Optical Properties of Quantum Dot-Graphene Hybrid Devices: Interplay of Charge and Energy Transfer

Dutta, R and Kakkar, S and Mondal, P and Chauhan, N and Basu, JK (2021) Electrical Tuning of Optical Properties of Quantum Dot-Graphene Hybrid Devices: Interplay of Charge and Energy Transfer. In: Journal of Physical Chemistry C, 125 (15). pp. 8314-8322.

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Abstract

The combination of semiconductor quantum dots (QD) and single-layer graphene (SLG) can lead to the formation of optoelectronic devices with enhanced sensitivity and can have extensive applications in the field of the photodetector and photovoltaics. The optical properties of the resultant hybrid material are controlled by the interplay of energy transfer between QDs and charge transfer between the QDs and SLG. By studying the steady-state and time-resolved photoluminescence spectroscopy of hybrid QD-SLG devices, we observe a subtle interplay of short- and long-range energy transfer between cadmium selenide (CdSe) QDs in a compact monolayer solid film placed in close proximity to an SLG and the charge transfer from the QD solid to SLG. At larger separation, δ, between the compact monolayer QD and SLG, the emission properties are dominated by mutual energy transfer between the QDs. At relatively smaller separation the emission from QDs, which is strongly quenched, is dominated by charge transfer between QDs and SLG. In addition, we are also able to tune the relative strength of energy and charge transfer by electrostatic doping through the back gate voltage, which provides a novel pathway to tune emission properties of these devices for possible applications as photodetectors, in photovoltaics, and for sensing. © 2021 American Chemical Society.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry C
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to American Chemical Society
Keywords:	Cadmium compounds; Cadmium metallography; Charge transfer; Electrostatic devices; Energy transfer; Graphene; Hybrid materials; II-VI semiconductors; Monolayers; Nanocrystals; Optical properties; Photodetectors; Photoluminescence spectroscopy; Photons; Selenium compounds; Semiconductor doping; Semiconductor quantum dots, Back-gate voltages; Cadmium selenides; Compact monolayers; Electrical tuning; Electrostatic doping; Emission properties; Enhanced sensitivity; Time resolved photoluminescence spectroscopies, Graphene devices
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	22 Jul 2021 05:56
Last Modified:	22 Jul 2021 05:56
URI:	http://eprints.iisc.ac.in/id/eprint/68882

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