Electronic structure and optical properties of novel monolayer gallium nitride and boron phosphide heterobilayers

2018 ◽  
Vol 20 (44) ◽  
pp. 28124-28134 ◽  
Author(s):  
A. Mogulkoc ◽  
Y. Mogulkoc ◽  
M. Modarresi ◽  
B. Alkan

An external electric field modifies the electronic structure, charge distribution and energy band gap in the heterobilayer of gallium nitride/boron phosphide.

2019 ◽  
Vol 16 (2) ◽  
pp. 0361
Author(s):  
Mahmood Et al.

      Spray pyrolysis technique was subjected to synthesized (SnO2)1-x (TiO2: CuO) x Thin films on different substrates like glass and single crystal silicon using. The structure of the deposited films was studied using x-ray diffraction. A more pronounced diffraction peaks of SnO2 while no peaks of (CuO , TiO2 ) phase appear in the X-ray profiles by increasing of the content of (TiO2 , CuO) in the sprayed films. Mixing concentration (TiO2 , CuO) influences on the size of the crystallites of the SnO2 films ,the size of crystallites of the spray paralyzed oxide films change in regular manner by increasing of (TiO2 , CuO) amount. The effect of mixing concentration on the optical properties of the films was also investigated. The reflectance and transmittance spectra  in the wavelength range (300-1100) nm were employed to determine the optical properties such as energy band gap (Eg) and refractive index (n),  extinction coefficient  (k) , real and imaginary parts of dielectric constants (ε1, ε2) for (SnO2)1-x(TiO2:CuO)x films. The energy band gap omit of which showed reduction from (3.65 to 2.2) eV by reducing of SnO2 amount from (100 to 70) % .The reduction of energy band gap was ascribed to the new tail states introduced in the band gap of tin oxide. The sensitivity of the prepared sensor film was determined resistance difference of the films when exposed to oxidizing gas. The data declared that the mixed SnO2 films have better sensitivity in comparison with unmixed films.


2001 ◽  
Vol 116 (1-3) ◽  
pp. 285-288 ◽  
Author(s):  
Xiaofeng Duan ◽  
Douglas S Dudis ◽  
Alan T Yeates

2011 ◽  
Vol 268-270 ◽  
pp. 1-3
Author(s):  
Ting Zhang ◽  
Ming He ◽  
Tao Chen ◽  
Guang Chang Wang

First principle calculations are performed on the structure, energy band gap, and dielectric properties of wurtzite and hexagonal BN by using a plane-wave pseudopotential method. It is found thath-BN has much narrower VB (valence band ) width and much sharper band edge than those ofw-BN. And the N 2sstates of the two phases of BN are dominant below 30.03 eV and the N 2pstates are dominant in the range between −20.62 and 20.32 eV.


2013 ◽  
Vol 27 (30) ◽  
pp. 1350170 ◽  
Author(s):  
ROSHAN ALI ◽  
R. KHANATA ◽  
BIN AMIN ◽  
G. MURTAZA ◽  
S. BIN OMRAN

Structural, elastic, electronic and optical properties as well as chemical bonding of the binary alkali metal selenides M 2 Se ( M = Li , Na , K , Rb ) were calculated using the full potential linearized augmented plane method. From the elastic constants it is inferred that these compounds are brittle in nature. The results of the electronic band structure show that Na 2 Se has a direct energy band gap (Γ-Γ), Li 2 Se has an indirect energy band gap (Γ- X), while K 2 Se and Rb 2 Se have an indirect energy band gap (X-Γ). Analysis of the charge distribution plots reveals a dominated ionic bonding in the herein studied compounds. Additionally, we have calculated the optical properties, namely, the real and the imaginary parts of the dielectric function, refractive index, extinction coefficient, optical conductivity and reflectivity for radiation up to 30.0 eV. All these compounds have direct energy band gap greater than 3.1 eV suggesting their use for manufacturing high frequency devices.


2017 ◽  
Vol 52 (17) ◽  
pp. 9990-10000 ◽  
Author(s):  
Y. Jiménez-Flores ◽  
M. Suárez-Quezada ◽  
J. B. Rojas-Trigos ◽  
L. Lartundo-Rojas ◽  
V. Suárez ◽  
...  

2021 ◽  
Author(s):  
Abdehafid Najim ◽  
Omar BAJJOU ◽  
Mustapha BOULGHALLAT ◽  
Mohammed Khenfouch ◽  
Khalid Rahmani

Abstract Electronic and optical properties of graphene oxide (GO), under an external electric field (Eext) applied in three directions of space (x, y, z), are investigated using the density functional theory (DFT). The application of the Eext, causes a significant modifications to the electronic and optical properties of GO material. It has change the band gap, total density of states (TDOS), partial density of states (PDOS), absorption coefficient (α), dielectric function, optical conductivity, refractive index and loss function. The band gap of GO layer increases under the effects of the Eext, applied in x and y directions. On the other hand, for z direction, the band gap decreases by the effects of the Eext. The peaks of the TDOS around the Fermi level, change by the Eext applied in (x, y, z) directions. The α peaks of the GO sheet, decreases by the Eext applied in x direction, and increases if Eext applied in y and z directions. It is found that, the electronic and optical properties of GO layer, could be affected by the effects of the Eext and by its direction of application.


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