Four-copper complexes in Si and the Cu-photoluminescence defect: A first-principles study

Abstract

Complexes containing four Cu impurities in Si are systematically investigated using density functional theory. The complexes include various combinations of substitutional and interstitial copper. The structures, formation and binding energies, approximate gap levels, and vibrational spectra are calculated and the results compared to the measured properties of the Cu PL defect. The best candidate out of those investigated is the Cu s1 Cu i3 complex recently proposed by Shirai et al. [J. Phys: Condens. Matter 21, 064249 (2009)]. The estimated positions of the gap levels of Cu s1 Cu in , with n = 0, . . . ,3, suggest a straightforward explanation as to why only the defects Cu s and Cu s1 Cu i3 occur in high-resistivity material.

Hydrogenation of the CuPL center in silicon

“…8 All these experimental findings lead to the conclusion that the Cu PL complex consists of a Cu s core decorated with three Cu i atoms. This conclusion is confirmed by ab initio calculations for the Cu s Cu i3 complex, 9,10 which reproduce the trigonal symmetry and thermal stability of the Cu PL center. 2,3,11 Also, the calculated deep levels for the Cu s Cu iN complexes (N ¼ 1, 2, 3) (Ref.…”

Deep electron traps and origin ofp-type conductivity in the earth-abundant solar-cell material Cu2ZnSnS4

“…Similar Cu clusters were proposed to exist in other semiconductor materials, such as silicon. 29,30 Because (Cu 2 ) Zn and (Cu 4 ) Sn are both fully compensated defects, they have no effect on the carrier concentration and recombination. Similarly, the low formation-energy defect pairs, such as Cu Zn +Zn Cu , are also fully compen-sated.…”

Transition-Metal Defects in Silicon

“…The comprehensive data presented here includes isotopic fingerprints of all studied centres, and the no-phonon (NP) PL energies and their isotope shifts. On the basis of preliminarily published results of this research project, some modelling efforts for the prototypical 1014 meV Cu 4 centre have already begun [39][40][41][42][43][44]. In addition, many of the observed NP PL lines show local and pseudo local vibrational mode (LVM/pLVM) replicas, which appear shifted in the optical spectrum by the energy amount of the involved vibrational mode.…”