Dresden 2006 – scientific programme
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HL: Halbleiterphysik
HL 14: II-VI semiconductors I
HL 14.7: Talk
Tuesday, March 28, 2006, 12:30–12:45, POT 151
Mid-infrared photocurrent spectroscopy of thin ZnO films — •H. Frenzel, A. Weber, H. v. Wenckstern, G. Biehne, H. Hochmuth, M. Lorenz, and M. Grundmann — Universität Leipzig, Institut für Experimentelle Physik II, Linnéstr. 5, 04103 Leipzig, Germany
We investigate mid-infrared photocurrent properties of thin ZnO films in a temperature range from 4 K to 300 K. The films were grown by pulsed laser deposition on a-plane sapphire substrates with substrate temperatures varying from 550∘C to 800∘C and oxygen partial pressures between 10−3 to 0.1 mbar [1]. High-quality Pd/ZnO Schottky diodes were realized by thermal evaporation of Pd on the Zn-face of the c-oriented thin films. The ideality factors of the diodes were characterized with Current–Voltage (I–U) measurements.
The optical absorption by shallow impurity traps in the ZnO space charge region of the diodes is studied with Fourier transform infrared photocurrent spectroscopy. The results are compared to non-optical techniques like deep level transient spectroscopy [2].
[1] E. M. Kaidashev, et al., Appl. Phys. Lett. 82, 3901 (2003).
[2] M. Grundmann, et al.: in Zinc Oxide – A Material for Micro- and Optoelectronic Applications (eds.: N. H. Nickel and E. Terukov), 47–57, Springer (2005).