The chemical nature of donors unintentionally present in ZnO nanocrystals prepared by chemical methods was studied by high-frequency electron paramagnetic resonance and electron nuclear double resonance. The results showed that H, which was present during preparation, and acted as a shallow donor in bulk material, was located in the Zn(OH)2 shell covering the nanocrystals. It was found that Li, probably in an interstitial position, was incorporated into the core of the nanocrystals.

Donors in ZnO Nanocrystals. Hofmann, D.M., Zhou, H., Pfisterer, D.R., Alves, H., Meyer, B.K., Baranov, P., Romanov, N., de Mello Donegá, C., Meijering, A., Orinskii, S., Blok, H., Schmidt, J.: Physica Status Solidi C, 2004, 1[4], 908-11