Ultrafast electron spin dynamics in ZnO and Zn1-xCoxO sol-gel thin films

Abstract

We probe the electron spin dynamics in ZnO and Zn1-xCo xO sol-gel films with time-resolved Faraday rotation spectroscopy. Dephasing times T2* on the order of nanoseconds are observed at room temperature due to charge-separated states. In ZnCoO the effective electron Landé g factor rises with increasing Co2+ concentration, providing the mean-field electron-Co2+ exchange energy N0α = +0.25 ± 0.02 eV. © Owned by the authors, published by EDP Sciences, 2013.