Effects of spontaneous and piezoelectric polarization fields on the electronic and optical properties in GaN/AlN quantum dots: multimillion-atomsp3d5s*tight-binding simulations

2014 ◽  
Vol 28 (3) ◽  
pp. 321-334 ◽  
Author(s):  
Sasi S. Sundaresan ◽  
Vamsi M. Gaddipati ◽  
Shaikh S. Ahmed
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Tight Binding ◽  
Electronic And Optical Properties ◽  
Piezoelectric Polarization

Microscopic tight-binding description for electronic and optical properties of InN/GaN quantum dots

2006 ◽  
Vol 3 (11) ◽  
pp. 3827-3831 ◽  
Author(s):  
S. Schulz ◽  
N. Baer ◽  
S. Schumacher ◽  
P. Gartner ◽  
F. Jahnke ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Tight Binding ◽  
Electronic And Optical Properties

Microscopic tight-binding description for electronic and optical properties of InN/GaN quantum dots

2006 ◽  
Vol 3 (11) ◽  
pp. 3631-3631
Author(s):  
S. Schulz ◽  
N. Baer ◽  
S. Schumacher ◽  
P. Gartner ◽  
F. Jahnke ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Tight Binding ◽  
Electronic And Optical Properties

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

2018 ◽  
Vol 32 (06) ◽  
pp. 1850084 ◽  
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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