Dresden 2009 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 40: ZnO: preparation and characterization III
HL 40.6: Talk
Thursday, March 26, 2009, 11:00–11:15, BEY 118
Photocurrent measurements on magnesium zinc oxide in the infrared spectral range — •Dieter Stender, Heiko Frenzel, Kerstin Brachwitz, Holger von Wenckstern, Gisela Biehne, Holger Hochmuth, and Marius Grundmann — Universität Leipzig, Institut für Experimentelle Physik II, Linnéstr. 5, 04103 Leipzig
We report on deep defects in MgxZn1−xO thin films with different magnesium content x up to 40%, investigated by Fourier-transform infrared photocurrent (FTIR-PC) spectroscopy in the mid and far infrared spectral range. The samples were grown on a-plane sapphire substrates by pulsed-laser deposition at a growth temperature of 700∘C and oxygen partial pressure of 0.016 mbar. Analogue studies on pure ZnO were performed in [1], in which the deep defects E1 at ∼110 meV, E3 at ∼320 meV and L2 at ∼260 meV have been observed. In MgZnO, peaks at similar energies have been found indicating the presence of common ZnO point defects. The results are discussed and compared with electrical measurements like deep level transient spectroscopy (DLTS) and temperature dependent admittance spectroscopy (TAS). Based on these results, ZnO/MgZnO single heterostructures as well as quantum wells were investigated in order to observe intersubband transitions.
[1] H. Frenzel et al., Phys. Rev. B 76, 035214 (2007)