Exploring Intrinsic Electron-Trapping Centers for Persistent Luminescence in Bi3+-Doped LiREGeO4 (RE = Y, Sc, Lu): Mechanistic Origin from First-Principles Calculations

2021 ◽  
Author(s):  
Zheng Qiao ◽  
Xuesong Wang ◽  
Chen Heng ◽  
Wei Jin ◽  
Lixin Ning
Keyword(s):  
First Principles ◽  
Electron Trapping ◽  
Persistent Luminescence ◽  
First Principles Calculations ◽  
Trapping Centers

Evaluation of the role of oxygen vacancies in La3GaGe5O16:Tb3+ persistent phosphor

2017 ◽  
Vol 31 (13) ◽  
pp. 1750144 ◽  
Author(s):  
He Duan ◽  
Ze Jia Lin ◽  
You Zhong Dong ◽  
Yan Huang
Keyword(s):  
First Principles ◽  
Oxygen Vacancies ◽  
Oxygen Deficiency ◽  
Ring Structure ◽  
Persistent Luminescence ◽  
First Principles Calculations ◽  
Color Tunable ◽  
Luminescence Performance ◽  
Trap Levels

The persistent luminescence performance of a novel color-tunable Tb[Formula: see text]-doped La[Formula: see text]GaGe[Formula: see text]O[Formula: see text] phosphor has been modified by oxygen-deficiency control with an aim to explore the strategy to improve the persistent luminescence property. First-principles calculations were combined with thermoluminescence (TL) measurements to evaluate the role of oxygen vacancies in persistent luminescence of La[Formula: see text]GaGe[Formula: see text]O[Formula: see text]:Tb[Formula: see text] persistent phosphor. Our results show that the oxygen vacancies that act as an electron trap center have a limited contribution to the persistent luminescence. The formation of the ring structure of La[Formula: see text]GaGe[Formula: see text]O[Formula: see text] crystal and the resulting localized trap levels are very different from that of other outstanding persistent phosphors, like Sr[Formula: see text]MgSi[Formula: see text]O[Formula: see text], etc. Such differences are closely related to the inferior performance of La[Formula: see text]GaGe[Formula: see text]O[Formula: see text]:Tb[Formula: see text] persistent phosphor.

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

To Bend or Not to Bend, the Dilemma of Multiple Bonds

2019 ◽  
Author(s):  
Michele Pizzocchero ◽  
Matteo Bonfanti ◽  
Rocco Martinazzo
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Main Group ◽  
First Principles Calculations ◽  
Group 14 ◽  
Multiple Bonds ◽  
Main Group Elements ◽  
Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Combined DFT and kinetic Monte Carlo study of a bridging-spillover mechanism on fluorine-decorating graphene

2020 ◽  
Author(s):  
Jing-hua Guo ◽  
Jin-Xiang Liu ◽  
Hongbo Wang ◽  
Haiying Liu ◽  
Gang Chen
Keyword(s):  
Monte Carlo ◽  
First Principles ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Study ◽  
First Principles Calculations ◽  
Graphene Surface

In this work, combining the first-principles calculations with kinetic Monte Carlo (KMC) simulations, we constructed an irregular carbon bridge on the graphene surface and explored the process of H migration...

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