A new perspective on the process of intrinsic point defects in α-Al2O3

2015 ◽  
Vol 17 (43) ◽  
pp. 29134-29141 ◽  
Author(s):  
Xin Xiang ◽  
Guikai Zhang ◽  
Xiaolin Wang ◽  
Tao Tang ◽  
Yan Shi
Keyword(s):  
Plane Wave ◽  
Point Defects ◽  
First Principles ◽  
Intrinsic Point Defects ◽  
Pseudopotential Calculations ◽  
Charge States ◽  
New Perspective ◽  
Α Al2o3

First-principles plane-wave pseudopotential calculations have been performed to study the charge states and energetics of intrinsic point defects as vacancies, interstitials and antisite atoms in α-Al2O3, and thus a new perspective on the process of intrinsic point defects has been proposed.

scholarly journals First-Principles Assessment of the Structure and Stability of 15 Intrinsic Point Defects in Zinc-Blende Indium Arsenide

Crystals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 48 ◽  
Author(s):  
Qing Peng ◽  
Nanjun Chen ◽  
Danhong Huang ◽  
Eric Heller ◽  
David Cardimona ◽  
...  
Keyword(s):  
Fermi Level ◽  
Charge State ◽  
Indium Arsenide ◽  
Point Defects ◽  
First Principles ◽  
Formation Energy ◽  
Fast Diffusion ◽  
Intrinsic Point Defects ◽  
Zinc Blende ◽  
Tetrahedral Sites

Point defects are inevitable, at least due to thermodynamics, and essential for engineering semiconductors. Herein, we investigate the formation and electronic structures of fifteen different kinds of intrinsic point defects of zinc blende indium arsenide (zb-InAs ) using first-principles calculations. For As-rich environment, substitutional point defects are the primary intrinsic point defects in zb-InAs until the n-type doping region with Fermi level above 0.32 eV is reached, where the dominant intrinsic point defects are changed to In vacancies. For In-rich environment, In tetrahedral interstitial has the lowest formation energy till n-type doped region with Fermi level 0.24 eV where substitutional point defects In A s take over. The dumbbell interstitials prefer < 110 > configurations. For tetrahedral interstitials, In atoms prefer 4-As tetrahedral site for both As-rich and In-rich environments until the Fermi level goes above 0.26 eV in n-type doped region, where In atoms acquire the same formation energy at both tetrahedral sites and the same charge state. This implies a fast diffusion along the t − T − t path among the tetrahedral sites for In atoms. The In vacancies V I n decrease quickly and monotonically with increasing Fermi level and has a q = − 3 e charge state at the same time. The most popular vacancy-type defect is V I n in an As-rich environment, but switches to V A s in an In-rich environment at light p-doped region when Fermi level below 0.2 eV. This study sheds light on the relative stabilities of these intrinsic point defects, their concentrations and possible diffusions, which is expected useful in defect-engineering zb-InAs based semiconductors, as well as the material design for radiation-tolerant electronics.

Search for Effective Sites of Proximity Gettering Induced by Ion Implantation in Si Wafers with First Principles Calculation

2015 ◽  
Vol 242 ◽  
pp. 271-276
Author(s):  
Sho Shirasawa ◽  
Koji Sueoka
Keyword(s):  
Heat Treatment ◽  
Binding Energy ◽  
Ion Implantation ◽  
Point Defects ◽  
First Principles ◽  
First Principles Calculation ◽  
Manufacturing Processes ◽  
Intrinsic Point Defects

Fe, Ni and Cu atoms diffuse very quickly in Si and are the main targets for metal gettering. W, Hf, and Mo atoms, for example, which diffuse very slowly in Si have also recently become gettering targets in addition to these metals. Therefore, proximity gettering techniques by using ion implantation are being considered. Not only implanted elements but intrinsic point defects exist and form several complexes after the heat treatment for Si crystal recovery. This research systematically investigated the binding energy of twelve important metals (Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Hf, Ta, and W) with implanted dopants (B, C, P, and As) and their complexes with intrinsic point defects (vacancies (Vs) and self-interstitials (Is)) by using first principles calculation. These data should be useful in the design of proximity gettering in LSI manufacturing processes.

scholarly journals The effect of vacancies and the substitution of p-block atoms on single-layer buckled germanium selenide

RSC Advances ◽  
2017 ◽  
Vol 7 (60) ◽  
pp. 37815-37822 ◽  
Author(s):  
F. Ersan ◽  
H. Arkin ◽  
E. Aktürk
Keyword(s):  
Density Functional Theory ◽  
Plane Wave ◽  
Point Defects ◽  
First Principles ◽  
Density Functional ◽  
Single Layer ◽  
Functional Theory ◽  
Germanium Selenide ◽  
Spin Polarized

This paper investigates the effect of point defects of both hole (Ge, Se) and substitution doping of p-block elements, in single-layer b-GeSe, based on first principles plane wave calculations within spin-polarized density functional theory.

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