scholarly journals Role of vacancies to p-type semiconducting properties of SiGe nanowires

2014 ◽  
Vol 2 (32) ◽  
pp. 6536-6546 ◽  
Author(s):  
Rulong Zhou ◽  
Bingyan Qu ◽  
Bo Zhang ◽  
Pengfei Li ◽  
Xiao Cheng Zeng
Keyword(s):  
Core Shell ◽  
First Principle ◽  
First Principle Calculations ◽  
Semiconducting Properties ◽  
P Type

On basis of the first-principle calculations, vacancies are proven to play important roles in p-type semiconducting properties of Si1−xGex nanowires (NW) and Ge/Si core/shell NW.

scholarly journals Unravelling the origin of the giant Zn deficiency in wurtzite type ZnO nanoparticles

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Adèle Renaud ◽  
Laurent Cario ◽  
Xavier Rocquefelte ◽  
Philippe Deniard ◽  
Eric Gautron ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Charge Carriers ◽  
Zn Deficiency ◽  
Core Shell ◽  
Bulk Materials ◽  
Nitrogen Doped ◽  
The Core ◽  
Zinc Peroxide ◽  
P Type

Abstract Owing to its high technological importance for optoelectronics, zinc oxide received much attention. In particular, the role of defects on its physical properties has been extensively studied as well as their thermodynamical stability. In particular, a large concentration of Zn vacancies in ZnO bulk materials is so far considered highly unstable. Here we report that the thermal decomposition of zinc peroxide produces wurtzite-type ZnO nanoparticles with an extraordinary large amount of zinc vacancies (>15%). These Zn vacancies segregate at the surface of the nanoparticles, as confirmed by ab initio calculations, to form a pseudo core-shell structure made of a dense ZnO sphere coated by a Zn free oxo-hydroxide mono layer. In others terms, oxygen terminated surfaces are privileged over zinc-terminated surfaces for passivation reasons what accounts for the Zn off-stoichiometry observed in ultra-fine powdered samples. Such Zn-deficient Zn1-xO nanoparticles exhibit an unprecedented photoluminescence signature suggesting that the core-shell-like edifice drastically influences the electronic structure of ZnO. This nanostructuration could be at the origin of the recent stabilisation of p-type charge carriers in nitrogen-doped ZnO nanoparticles.

Role of H impurity as compensating center in BiFeO3 by first-principle calculations

2021 ◽  
Vol 96 (12) ◽  
pp. 125813
Author(s):  
Shaan Ameer ◽  
Kajal Jindal ◽  
Monika Tomar ◽  
Vinay Gupta ◽  
Pradip K Jha
Keyword(s):  
First Principle ◽  
First Principle Calculations

Theoretical Study of the Effect of (F, Li) Codoping on P-Type Tendency in ZnO

2011 ◽  
Vol 189-193 ◽  
pp. 1660-1663
Author(s):  
Zhi Hua Xiong ◽  
Lan Li Chen ◽  
Qi Xin Wan
Keyword(s):  
Formation Energy ◽  
Theoretical Study ◽  
First Principle ◽  
First Principle Calculations ◽  
Rich Condition ◽  
Transition Level ◽  
P Type ◽  
Zno Doping

Based on the first-principle calculations, we present a study for p-type ZnO doping. The calculated results show that (F, Li) codoping can suppress the formation of interstitial Li because the formation energy of FO-LiZn is lower than that of FO-Lii under O-rich condition. However, it is also found that FO-LiZn codoping could not realize p-type ZnO because FO-LiZn forms a fully passive complex. Interestingly, we further find FO-2LiZn is a stable acceptor that has lower formation energy and shallower transition level under O-rich condition. We expect this study might be helpful for synthesizing good p-type ZnO by controlling (F, Li) codoping.

scholarly journals Structure, Magnetism, and Electronic Properties of Inverse Heusler Alloy Ti2CoAl/MgO(100) Herterojuction: The Role of Interfaces

2018 ◽  
Vol 8 (12) ◽  
pp. 2336 ◽  
Author(s):  
Bo Wu ◽  
Haishen Huang ◽  
Guangdong Zhou ◽  
Yu Feng ◽  
Ying Chen ◽  
...  
Keyword(s):  
Spin Polarization ◽  
First Principle ◽  
Half Metallicity ◽  
Half Metallic ◽  
Atomic Magnetic Moment ◽  
First Principle Calculations ◽  
Metal Atoms ◽  
Interface Structures ◽  
The Ideal

In this study, the interface structures, atom-resolved magnetism, density of states, and spin polarization of 10 possible atomic terminations in the Ti2CoAl/MgO(100) heterojunction were comprehensively investigated using first-principle calculations. In the equilibrium interface structures, the length of the alloy–Mg bond was found to be much longer than that of the alloy–O bond because of the forceful repulsion interactions between the Heusler interface atoms and Mg atoms. The competition among d-electronic hybridization, d-electronic localization, and the moving effect of the interface metal atoms played an important role in the interface atomic magnetic moment. Unexpected interface states appeared in the half-metallic gap for all terminations. The “ideal” half-metallicity observed in the bulk had been destroyed. In TiAl–Mg and AlAl–O terminations, the maximal spin polarization of about 65% could be reserved. The tunnel magnetoresistance (TMR) value was deduced to be lower than 150% in the Ti2CoAl/MgO(100) heterojunction at low temperature.

Pressure effect on the hardness of diamond and W2B5: First-principle calculations

2017 ◽  
Vol 31 (12) ◽  
pp. 1750137 ◽  
Author(s):  
Shi-Quan Feng ◽  
Yang Yang ◽  
Jun-Yu Li ◽  
Xiao-Xu Jiang ◽  
Hai-Ning Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Electronic Properties ◽  
Elastic Properties ◽  
Structural Stability ◽  
Pressure Effect ◽  
Empirical Method ◽  
First Principle ◽  
First Principle Calculations ◽  
Semi Empirical

In this paper, we employed first-principle calculations to investigate the elastic properties, electronic properties and hardness of diamond and hexagonal W2B5 compounds under high pressure. The elastic properties were carried out to discuss the structural stability and the bond components of diamond and hexagonal W2B5. The electronic properties were presented to analysis the change of the bond components for W2B5. In addition, the hardness of these two crystals under high pressure was calculated by a semi-empirical method considering the role of metallic components and the effect of pressure on the hardness of diamond and hexagonal W2B5 was discussed.

DFT coupled with NEGF study of the electronic properties and ballistic transport performances of 2D SbSiTe3

Nanoscale ◽  
2020 ◽  
Vol 12 (18) ◽  
pp. 9958-9963 ◽  
Author(s):  
Xuemin Hu ◽  
Hengze Qu ◽  
Lili Xu ◽  
Wenqiang Liu ◽  
Tingting Guo ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
Ballistic Transport ◽  
Wide Band ◽  
Valence Band Maximum ◽  
First Principle ◽  
Wide Band Gap ◽  
Short Channel ◽  
First Principle Calculations ◽  
Channel Effect ◽  
P Type

By first-principle calculations, we predicted that monolayer SbSiTe3 possesses a wide band gap with a flat valence band maximum. The p-type field effect transistors can effectively suppress the short channel effect at sub-10 nm.

1758-P: Type 2 Diabetes–Associated Mood Disorders: Role of Insulin Resistance in Serotonergic Neurons

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 1758-P
Author(s):  
HUGO MARTIN ◽  
SÉBASTIEN BULLICH ◽  
FABIEN DUCROCQ ◽  
MARION GRALAND ◽  
CLARA OLIVRY ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Mood Disorders ◽  
Serotonergic Neurons ◽  
P Type

Freedom and Responsibility in Neoplatonist Thought

2020 ◽  
Author(s):  
Ursula Coope
Keyword(s):  
First Principle ◽  
Human Beings ◽  
Human Soul ◽  
The One ◽  
Freedom And Responsibility

The Neoplatonists have a perfectionist view of freedom: an entity is free to the extent that it succeeds in making itself good. Free entities are wholly in control of themselves: they are self-determining, self-constituting, and self-knowing. Neoplatonist philosophers argue that such freedom is only possible for nonbodily things. The human soul is free insofar as it rises above bodily things and engages in intellection, but when it turns its desires to bodily things, it is drawn under the sway of fate and becomes enslaved. This book discusses this notion of freedom, and its relation to questions about responsibility. It explains the important role of notions of self-reflexivity in Neoplatonist accounts of both freedom and responsibility. Part I sets out the puzzles Neoplatonist philosophers face about freedom and responsibility and explains how these puzzles arise from earlier discussions. Part II looks at the metaphysical underpinnings of the Neoplatonist notion of freedom (concentrating especially on the views of Plotinus and Proclus). In what sense (if any) is the ultimate first principle of everything (the One) free? If everything else is under this ultimate first principle, how can anything other than the One be free? What is the connection between freedom and nonbodiliness? Part III looks at questions about responsibility, arising from this perfectionist view of freedom. Why are human beings responsible for their behaviour, in a way that other animals are not? If we are enslaved when we act viciously, how can we be to blame for our vicious actions and choices?

Sign in / Sign up

Export Citation Format

Share Document