Hybrid density-functional theory calculations on surface effects in Co doped ZnO nanowires

TL;DR

This study uses hybrid density-functional theory to explore how surface passivation affects cobalt doping in ZnO nanowires, revealing environmental influences on Co incorporation and segregation.

Contribution

It provides new insights into how surface passivation alters Co atom placement in ZnO nanowires, informing nanostructure doping strategies.

Findings

Cobalt segregates to the surface without passivation.

Hydrogen passivation favors Co incorporation at inner sites.

Surface environment influences Co doping behavior.

Abstract

In this work we have employed density-functional theory with hybrid functionals to investigate the atomic and electronic structure of bare and hydrogenated Co doped ZnO nanowires. We find that in the absence of passivation on the nanowire surface, the cobalt atoms segregate to the surface. On the other hand, under hydrogen passivation, the incorporation of Co is more favorable at inner sites. This suggests that the incorporation of Co in nanostructures has a dependence on the environment and may be facilitated by external atoms and relaxation of the surface.