Optical bands related to dislocations in Si

Abstract

First-principles calculations are used to investigate the interaction of self-interstitial aggregates with the 90° partial dislocation in Si. We find that I4 is bound to the line with an energy of around 3 eV. The defect causes deep levels to appear in the band gap and optical transitions between these levels may account for the luminescent bands relating to plastically deformed Si.

Investigation of the atomic core structure of the ($ \vec a + \vec c $)‐mixed dislocation in wurtzite GaN

“…However, in the present case, the size of the models is out of reach of ab-initio techniques, the electronic structure of the ( ) a c + -mixed dislocation was then explored using the SCC-DFTB methodology. Over several applications, the latter method has proven to provide electronic structures qualitatively in agreement with those obtained by more sophisticated ab-initio methods [14,15]. Although we end up with deep and shallow levels in the bandgap for the two core configurations, the calculated electronic structure show some different features (Fig.…”

Effect of high pressure isostatic annealing on oxygen segregation in Czochralski silicon

“…19 This hypothesis is also in agreement with the theoretical anticipation of Blumenau et al, 20 who showed that the isolated tetra selfinterstitial defects in silicon, which present a very shallow acceptor level, should emit in this range of energies. 19 This hypothesis is also in agreement with the theoretical anticipation of Blumenau et al, 20 who showed that the isolated tetra selfinterstitial defects in silicon, which present a very shallow acceptor level, should emit in this range of energies.…”

Enhancement of room temperature dislocation-related photoluminescence of electron irradiated silicon

“…From the first-principle calculations, it was shown that the I 4 defect clusters could bring deep levels in the band gap causing the optical transitions between these levels, which may account for the dislocations related luminescence. 20 Some other studies, such as inducing super saturation of non-equilibrium self-interstitials by ion implantation forming a silicon layer in which compression stresses appeared, also shown the strong D1/D2 luminescence. 34 On the other hand, during the high temperature annealing, oxygen atoms could diffuse quickly and get gathered at dislocations in CZ silicon, 35 which is also confirmed by the FTIR results in our case.…”

“…9,10 In fact, four photoluminescence (PL) lines related to dislocations (D1 to D4 lines) were first detected at 4.2 K in 1970s 11,12 and investigated intensively in the last three decades. [13][14][15][16][17][18][19][20][21][22][23][24] However, the radiative-recombination mechanism of excessive carriers at dislocations is still unclear. The major concerns are about the nature of the D1 and D2 lines' luminescence centers and the role of impurities and point defects during the recombination process.…”