Vacancy-mediated diffusion in disordered alloys: Ge self-diffusion inSi1−xGex

E centers in ternary Si1−x−yGexSny random alloys

“…This fact is in agreement with previous studies of Si 1−x Ge x , where the 2NN environment affected the stability of E centers by up to 0.17 eV and the formation of vacancies by 0.10 eV. 31,35 The significant impact of the local environment on the stability of the E centers will result in an inhomogeneous distribution of E centers in Si 1−x−y Ge x Sn y ternary alloys. Nevertheless, the binding energies of the most strongly bound AsV pairs in Si 0.375 Ge 0.5 Sn 0.125 are within the range of the binding energies of AsV pairs in Si ͑Ϫ1.23 eV͒ and Ge ͑Ϫ0.52͒.…”

“…This experimental observation was also supported by DFT studies using the SQS approach. 31,35 The second-NN ͑2NN͒ environment around the E center can also affect its stability to a lesser degree compared to the NN environment, but still to a significant extent. For example, the binding energy of an As Si V Si pair, in which both the As and the V have two Ge atoms and one Si atom at NN sites, can vary as much as 0.34 eV depending on the 2NN environment.…”

Nonlinear stability ofEcenters inSi1−xGex: Electronic structure calculations

“…7 As the aggressive scaling of modern devices will soon lead to devices with characteristic dimensions of only a few nanometers, the understanding of atomic diffusion and the stability of related complexes is becoming increasingly important in group IV semiconductors. [8][9][10][11][12] The most fundamental process of matter transport in Si 1−x Ge x is self-diffusion, which has been studied by both experimental [13][14][15][16][17][18][19][20] and theoretical 21,22 methods. Although E centers have been studied extensively in Si ͑Refs.…”

“…In recent studies, [31][32][33] both positronannihilation spectroscopy ͑PAS͒ and density-functional theory ͑DFT͒ were used to study phosphorus-vacancy ͑PV͒ pairs in Si-rich Si 1−x Ge x . Previous theoretical studies of Si 1−x Ge x have been devoted to the effect of composition on the formation of V, V-mediated diffusion, 2,21,22 and the interaction of V with extended defects. 34 The aim of the present study is to contribute toward a better understanding of the role of Si 1−x Ge x composition on the stability and properties of E centers.…”

Ab initioprediction of vacancy properties in concentrated alloys: The case of fcc Cu-Ni

“…[20,21]), and from the theoretical side also, there have been rather few studies that deal with specific alloy systems. Initially using empirical potentials [22][23][24][25], and later through ab initio approaches, both through supercell calculations [26][27][28][29] and ab initio based cluster expansions [30][31][32][33], it has been established that the local atomic environment around a vacancy plays a significant role. While the influence of vacancies on phase stability [30,34] and kinetics [31][32][33] received some attention for Al-Ni [30], Sc-S [34], and Al-Li [31][32][33] alloys, the actual vacancy properties in specific alloys were mostly neglected with the exception of an empirical potential study of Cu-Ni alloys by Zhao et al [24].…”