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Title: Mechanism of creation and destruction of oxygen interstitial atoms by nonpolar zinc oxide(101̄0) surfaces
Oxygen vacancies (V O ) influence many properties of ZnO in semiconductor devices, yet synthesis methods leave behind variable and unpredictable V O concentrations. Oxygen interstitials (O i ) move far more rapidly, so post-synthesis introduction of O i to control the V O concentration would be desirable. Free surfaces offer such an introduction mechanism if they are free of poisoning foreign adsorbates. Here, isotopic exchange experiments between nonpolar ZnO(101̄0) and O 2 gas, together with mesoscale modeling and first-principles calculations, point to an activation barrier for injection only 0.1–0.2 eV higher than for bulk site hopping. The modest barrier for hopping in turn enables diffusion lengths of tens to hundreds of nanometers only slightly above room temperature, which should facilitate defect engineering under very modest conditions. In addition, low hopping barriers coupled with statistical considerations lead to important qualitative manifestations in diffusion via an interstitialcy mechanism that does not occur for vacancies.  more » « less
Award ID(s):
1709327
PAR ID:
10327926
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
23
Issue:
30
ISSN:
1463-9076
Page Range / eLocation ID:
16423 to 16435
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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