Theory of Li in ZnO: A limitation for Li-based p-type doping

p-type doping of ZnO has thus-far proved difficult. Some reports indicate that Li substituting for Zn would be a shallow acceptor, with work on ferroelectric material showing that Li can be incorporated at the atomic percent concentrations. However, Li doping typically increases the resistivity of otherwise n-type material. We report on the structure and properties of Li in ZnO as predicted by first principles calculations. We also study the diffusion of interstitial Li and show that doping may be limited by the formation of Li₂O inclusions and the formation of strongly bound passive Li-H complexes.