Magnetic resonance spectroscopy of hydrogen shallow donors in aluminum-doped zinc oxide prepared by sol–gel processing

Hydrogen shallow donors in sol–gel-prepared pristine and Al-doped ZnO systems have been investigated by electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) measurements. It is shown that the hydrogen shallow donors in the Al-doped ZnO system mostly occupy the interstitial sites as in the case of the pristine ZnO system. Our high-resolution NMR measurements sensitively reflected the slightly distinct lattice environments in the pristine and Al-doped ZnO systems.