scholarly journals Moiré band model and band gaps of graphene on hexagonal boron nitride

2017 ◽  
Vol 96 (8) ◽  
Author(s):  
Jeil Jung ◽  
Evan Laksono ◽  
Ashley M. DaSilva ◽  
Allan H. MacDonald ◽  
Marcin Mucha-Kruczyński ◽  
...  
2018 ◽  
Vol 32 (06) ◽  
pp. 1850084 ◽  
Author(s):  
Yi-Min Ding ◽  
Jun-Jie Shi ◽  
Min Zhang ◽  
Meng Wu ◽  
Hui Wang ◽  
...  

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.


2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Jeil Jung ◽  
Ashley M. DaSilva ◽  
Allan H. MacDonald ◽  
Shaffique Adam

2020 ◽  
Vol 8 (28) ◽  
pp. 9558-9568
Author(s):  
Soon Siang Chng ◽  
Minmin Zhu ◽  
Zehui Du ◽  
Xizu Wang ◽  
Matthew Whiteside ◽  
...  

The isotope-enriched h-BN films exhibited a dielectrics dispersion with low dielectric loss, below 1.3%. Their optical band gaps depend on isotopic composition (5.54 to 5.79 eV). Thermal conductivity of pure B10/11N are enhanced by around 231%.


2014 ◽  
Vol 89 (20) ◽  
Author(s):  
Menno Bokdam ◽  
Taher Amlaki ◽  
Geert Brocks ◽  
Paul J. Kelly

RSC Advances ◽  
2019 ◽  
Vol 9 (60) ◽  
pp. 35297-35303
Author(s):  
Maoyun Di ◽  
Lin Fu ◽  
Yong Wang ◽  
Kaiyu Zhang ◽  
Yongjie Xu ◽  
...  

Distinct band gaps appear in both of the heterostructures, while the linear band structure is retained in α-GY/α-BNy.


2019 ◽  
Author(s):  
Matěj Velický ◽  
Sheng Hu ◽  
Colin R. Woods ◽  
Peter S. Toth ◽  
Viktor Zólyomi ◽  
...  

Marcus-Hush theory of electron transfer is one of the pillars of modern electrochemistry with a large body of supporting experimental evidence presented to date. However, some predictions, such as the electrochemical behavior at microdisk electrodes, remain unverified. Herein, we present a study of electron tunneling across a hexagonal boron nitride barrier between a graphite electrode and redox levels in a liquid solution. This was achieved by the fabrication of microdisk electrodes with a typical diameter of 5 µm. Analysis of voltammetric measurements, using two common redox mediators, yielded several electrochemical parameters, including the electron transfer rate constant, limiting current, and transfer coefficient. They show a significant departure from the Butler-Volmer behavior in a clear manifestation of the Marcus-Hush theory of electron transfer. In addition, our system provides a novel experimental platform, which could be applied to address a number of scientific problems such as identification of reaction mechanisms, surface modification, or long-range electron transfer.


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