Hydrogen, Acceptors, and H-Acceptor Complexes in GaN

1995 ◽  
Vol 395 ◽  
Author(s):  
Andrea Bosin ◽  
Vincenzo Fiorentini ◽  
David Vanderbilt
Keyword(s):  
Complex Formation ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Atomic Hydrogen ◽  
Formation Energy ◽  
Impurity Level ◽  
Mbe Growth ◽  
Hydrogen Incorporation ◽  
Shallow Impurity ◽  
Mg Doped

ABSTRACTWe present ab-initio calculations on energetics and geometries of atomic hydrogen, of several candidate acceptors, and of H-acceptor complexes in wurtzite GaN For the H-Mg complex in Mg-doped GaN, we calculate the vibrational frequencies of H. Hydrogen is found to be a negative-U center. H-acceptor complex formation is always exothermic. Substitutional Be has a low formation energy and a shallow impurity level, which makes it a good candidate for p-doping in MBE growth. CN appears not to be shallow. Atomic hydrogen incorporation in undoped GaN is disfavored in an H2 atmosphere; it becomes favorable in p and n-type conditions in atomic H environments.

scholarly journals STUDY OF POTASSIUM INTERCALATION IN TO THE GRAPHENE/MoS STRUCTURE

2021 ◽  
pp. 639-645
Author(s):  
Илья Васильевич Чепкасов
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Formation Energy ◽  
Potassium Atom ◽  
Structure Calculation ◽  
Mos Structure ◽  
Layer Graphene ◽  
Low Concentrations ◽  
The Difference ◽  
Covalent Nature

Используя современные расчеты из первых принципов, в данной работе мы систематически изучали интеркаляцию атомов калия в гибридную двухслойную структуру графене/ MoS. В ходе исследования были определенны концентрации атомов калия при которых энергия формирования является отрицательной. Так в частности при концентрации атомов калия, по отношению к атомам молибдена, не более x = 0,43 формирование слоя атомов калия между слоями графен/ MoS является энергетически выгодным. Начиная с концентрации атомов калия x > 0,75 наблюдается увеличение расстояние между слоями графен и MoS, что в дальнейшем приводит к разрушению структуры. Расчет зарядов показал, что атом калия при небольших концентрациях отдает примерно 0,8 - 0,85 электрона, 0,35 из которых перетекает на атомы углерода, а 0,4 - 0,5 перетекает на дисульфид молибдена. Расчёт разность электронных плотностей показал, что связь между слоями графена, дисульфид молибдена и калия имеет ковалентный характер. Using modern ab-initio calculations, in this work, we systematically studied the intercalation of potassium atoms into a hybrid two-layer graphene/MoS structure. In the course of the study, concentrations of potassium atoms were determined at which the formation energy is negative. So, in particular, when the concentration of potassium atoms (in relation to molybdenum atoms) is not more than x = 0,43, formation of a layer of potassium atoms between the graphene/ MoS layers is energetically favorable. Beginning with the concentration of potassium atoms x > 0,75 , an increase in the distance between the graphene and MoS layers is observed, which further leads to destruction of the structure. Calculation of charges showed that a potassium atom at low concentrations gives up about 0,8 - 0,85 electrons, 0,35 of which flow on carbon atoms, and 0,4 - 0,5 to molybdenum disulfide. Calculation of the difference in electron densities showed that the bond between the layers of graphene, molybdenum and potassium disulfide has a covalent nature.

Hydrogen incorporation in crystalline zircon: Insight from ab initio calculations

2013 ◽  
Vol 98 (4) ◽  
pp. 745-751 ◽  
Author(s):  
S. M. Botis ◽  
Y. Pan ◽  
R. C. Ewing
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Hydrogen Incorporation

The energetic and electronic properties of atomic hydrogen on MgO(001) surface: Tight-binding and Ab initio calculations

2001 ◽  
Vol 18 (4) ◽  
pp. 512-517 ◽  
Author(s):  
Soong-Hyuck Suh ◽  
Woong-Ki Min ◽  
Woo-Chul Kim ◽  
Seung-Bak Rho ◽  
Won-Sool Ahn ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electronic Properties ◽  
Atomic Hydrogen ◽  
Tight Binding

Energy levels of atomic hydrogen in germanium from ab-initio calculations

2006 ◽  
Vol 9 (4-5) ◽  
pp. 503-506 ◽  
Author(s):  
L.M. Almeida ◽  
J. Coutinho ◽  
V.J.B. Torres ◽  
R. Jones ◽  
P.R. Briddon
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Atomic Hydrogen ◽  
Energy Levels

Structural and electrochemical properties of Mg-doped nickel based cathode materials LiNi0.6Co0.2Mn0.2−xMgxO2 for lithium ion batteries

RSC Advances ◽  
2015 ◽  
Vol 5 (108) ◽  
pp. 88773-88779 ◽  
Author(s):  
Zhenjun Huang ◽  
Zhixing Wang ◽  
Xiaobo Zheng ◽  
Huajun Guo ◽  
Xinhai Li ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Electrochemical Properties ◽  
Ab Initio ◽  
Lithium Ion Batteries ◽  
Cathode Materials ◽  
Lithium Ion ◽  
The Impact ◽  
Mg Doped

Combined with experiments and ab initio calculations, we investigated the impact of the substitution of Mn with Mg in LiNi0.6Co0.2Mn0.2O2.

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