Vacancies and interstitials in indium nitride: Vacancy clustering and molecular bondlike formation from first principles

Abstract

We investigate the structural and electronic properties and formation energies of vacancy, interstitial, and antisite defects, as well as complex formation, in wurtzite InN using first-principles calculations. The N interstitial, which forms a split-interstitial configuration with a N 2 -like bonding, has the lowest formation energy under N-rich conditions in p-type material, where it is a triple donor. We find that indium vacancies have a tendency to form "clusters," which results in local nitrogen-rich regions and the formation of N x -molecular-like bonds. These complexes are amphoteric, have a relatively high formation energy, and are formed more readily under N-rich conditions. The nitrogen vacancy is a low energy defect under more In-rich conditions, and in p-type material it acts as a single and triple donor. In the neutral and negative charge states, we find nitrogen vacancies also prefer to be situated close to one another and to cluster, giving rise to local In-rich regions with electron localization at these metalliclike bonding configurations. The indium antisite in the 4+ charge state is the lowest-energy defect under In-rich conditions in p-type material and thus also acts as a donor. Our findings shed light on, and help explain, recent and sometimes conflicting, experimental observations.

Defect evolution and interplay in n-type InN

“…This is in good agreement with the calculated value of 1.6 eV (Ref. 16) and indicates that isolated V In are mobile during InN growth (assuming usual growth temperatures of, e.g., $550 C in MBE).…”

“…Hence, we conclude that in-grown V In are stabilized through the formation of complexes with V N . This is supported by recent DFT results 16 which predict a positive binding energy between V In and V N . Vacancy-stabilization through the formation of vacancy-donor complexes has been observed also in GaN (Ref.…”

Defect-Controlled Electronic Structure and Phase Stability in Thermoelectric Skutterudite CoSb3

“…The binding energy is defined to consider the formation of a complex defect, 35 ( Here, we also examine the possibility of Se i +Se Sb In Se+Te co-doped CoSb 3 , the formation energy of the neutral Se Sb +Te Sb defect is much lower than that of the Se i +Te Sb defect with a -1 charge state in the Co rich region (Figure 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 10 to the system, leading to M Sb as a donor impurity with a +1 charge state, agreeing with the defect formation energy results as shown in Figure 2(c)-2(h).…”

Vacancy-type defects in Mg-doped GaN grown by ammonia-based molecular beam epitaxy probed using a monoenergetic positron beam

“…10 Some of V N preferentially couple with V Ga and can form stable complexes. 42 We can therefore conclude that the observed behavior of defects in the [Mg] ¼ 1 Â 10 20 cm À3 sample is attributable to the introduction of V N and the related formation of V Ga V N complexes. In Fig.…”