Electron spin resonance of Zn_(1-x)Mg_xO thin films grown by plasma-assisted molecular beam epitaxy

摘要

Zn_(1-x)Mg_xO thin films with a Mg content x between 0 and 0.42 grown by plasma-assisted molecular beam epitaxy on c-plane sapphire substrates were investigated by electron spin resonance at 5 K. Above band gap illumination induces a persistent resonance signal, which is attributed to free conduction band electrons. The g-factors of the Zn_(1-x)Mg_xO epitaxial layers and their anisotropy were determined experimentally and an increase from g_‖= 1.957 for x=0 to g_‖= 1.970 for x=0.42 was found, accompanied by a decrease in anisotropy. A comparison with g-factors of the Al_xGa_(1-x)N system is also given.