Deep-level transient spectroscopy was used to characterise four defects with
shallow levels in specimens grown via pulsed laser deposition. These defects all
had deep-level transient spectroscopic peaks below 100K From deep-level transient
spectroscopic measurements and Arrhenius plots, the energy levels of the defects
were calculated to be 31, 64, 100 and 140meV, respectively, below the conduction
band. The 100meV defect exhibited metastable behaviour. Annealing under reverse
bias at above 130K introduced it, while annealing under zero bias above 110K
removed it. The 64 and 140meV defects exhibited a strong electric field assisted
emission; indicating that they may be donors.
Electronic Properties of Shallow Level Defects in ZnO Grown by Pulsed Laser
Deposition. F.D.Auret, W.E.Meyer, P.J.J.Van Rensburg, M.Hayes, J.M.Nel,
H.Von Wenckstern, H.Hochmuth, G.Biehne, M.Lorenz, M.Grundmann: Journal of
Physics - Conference Series, 2008, 100[4], 042038