Influence of Interstitial Cluster Families on Post-Synthesis Defect Manipulation and Purification of Oxides Using Submerged Surfaces

Injection of interstitial atoms via specially treated surfaces submerged in liquid water near room temperature presents a promising method for post-synthesis defect manipulation and isotopic purification in device structures. However, this approach can be constrained by trapping reactions that lead to the formation of small defect clusters, the compositions and dissociation barriers of which remain largely unknown. This study aims to fill this knowledge gap by determining the dissociation energies of oxygen interstitial traps in rutile TiO2 and wurtzite ZnO when exposed to liquid water. Isotopic self-diffusion experiments using 18O, along with progressive annealing techniques, indicate that these traps are small interstitial clusters with dissociation energies ranging from 1.3 to 1.9 eV. These clusters likely form a family with varying numbers, compositions, and configurations of O and H atoms. In the case of TiO2, native interstitial clusters remaining from the synthesis process may also contribute to the trapping behavior. The existence of such small interstitial clusters is likely widespread in semiconducting oxides and has important implications for post-synthesis defect control and isotopic purification using submerged surfaces.