Photophysical Properties of Multilayer Graphene–Quantum Dots Hybrid Structures

Photoelectrical and photoluminescent properties of multilayer graphene (MLG)–quantum dots (QD) hybrid structures have been studied. It has been shown that the average rate of transfer from QDs to the MLG can be estimated via photoinduced processes on the QDs’ surfaces. A monolayer of CdSe QDs can double the photoresponse amplitude of multilayer graphene, without influencing its characteristic photoresponse time. It has been found that efficient charge or energy transfer from QDs to MLG with a rate higher than 3 × 108 s−1 strongly inhibits photoinduced processes on the QD surfaces and provides photostability for QD-based structures.

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Photostability and Photoinduced Processes in CuInS2/ZnS Quantum Dots and Their Hybrid Structures with Multilayer Graphene Nanoribbons

Optics and Spectroscopy ◽

10.1134/s0030400x20110223 ◽

2020 ◽

Vol 128 (11) ◽

pp. 1901-1909

Author(s):

I. A. Reznik ◽

D. A. Kurshanov ◽

A. Yu. Dubovik ◽

M. A. Baranov ◽

S. A. Moshkalev ◽

...

Keyword(s):

Quantum Dots ◽

Graphene Nanoribbons ◽

Hybrid Structures ◽

Multilayer Graphene ◽

Photoinduced Processes

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Liquid crystalline multilayer graphene quantum dots with hackelite structures: Characterisation and application for sensing nitrophenols

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2018.04.116 ◽

2018 ◽

Vol 268 ◽

pp. 100-107 ◽

Cited By ~ 4

Author(s):

Harnish Soni ◽

Padmaja Pamidimukkala

Keyword(s):

Quantum Dots ◽

Liquid Crystalline ◽

Graphene Quantum Dots ◽

Multilayer Graphene

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Tuning the electronic and optical properties of hexagonal boron-nitride nanosheet by inserting graphene quantum dots

Modern Physics Letters B ◽

10.1142/s0217984918500847 ◽

2018 ◽

Vol 32 (06) ◽

pp. 1850084 ◽

Cited By ~ 2

Author(s):

Yi-Min Ding ◽

Jun-Jie Shi ◽

Min Zhang ◽

Meng Wu ◽

Hui Wang ◽

...

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Boron Nitride ◽

Hexagonal Boron Nitride ◽

Graphene Quantum Dots ◽

Band Gaps ◽

Hybrid Structures ◽

Electronic And Optical Properties ◽

Boron Nitride Nanosheet ◽

Optoelectronic Nanodevices

It is difficult to integrate two-dimensional (2D) graphene and hexagonal boron-nitride (h-BN) in optoelectronic nanodevices, due to the semi-metal and insulator characteristic of graphene and h-BN, respectively. Using the state-of-the-art first-principles calculations based on many-body perturbation theory, we investigate the electronic and optical properties of h-BN nanosheet embedded with graphene dots. We find that C atom impurities doped in h-BN nanosheet tend to phase-separate into graphene quantum dots (QD), and BNC hybrid structure, i.e. a graphene dot within a h-BN background, can be formed. The band gaps of BNC hybrid structures have an inverse relationship with the size of graphene dot. The calculated optical band gaps for BNC structures vary from 4.71 eV to 3.77 eV, which are much smaller than that of h-BN nanosheet. Furthermore, the valence band maximum is located in C atoms bonded to B atoms and conduction band minimum is located in C atoms bonded to N atoms, which means the electron and hole wave functions are closely distributed around the graphene dot. The bound excitons, localized around the graphene dot, determine the optical spectra of the BNC hybrid structures, in which the exciton binding energies decrease with increase in the size of graphene dots. Our results provide an important theoretical basis for the design and development of BNC-based optoelectronic nanodevices.

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