Paper TF-TuA8
Growth Mechanism and Properties of Mg_xZn_(1-x)O Nanocomposites by Atomic Layer Deposition

Tuesday, October 19, 2010, 4:20 pm, Room Ruidoso

Magnesium-zinc oxide (Mg_xZn_(1-x)O) ternary films are an interesting class of alloy materials in which the band gap can be tuned by adjusting the Mg doping concentration. Consequently, Mg_xZn_(1-x)O has been widely studied for application in the fields such as electronics, optics, photoelectronics, and solar cells. Mg_xZn_(1-x)O thin films have been fabricated through a variety of methods including chemical vapor deposition, physical vapor deposition, molecular beam deposition, and ALD. Although there have recently been a few reports describing ALD Mg_xZn_(1-x)O for application in photvoltaics, there has been no detailed study of the growth mechanism and properties of the ALD Mg_xZn_(1-x)O thin films.

In this work, the ALD Mg_xZn_(1-x)O was systematically explored with different doping concentration of Mg by using diethyl zinc (DEZ), bis-cyclopentadienyl-magnesium (Cp₂Mg) and H₂O as the precursors. The growth mechanism was investigated using quartz crystal microbalance and quadrupole mass spectrometry measurements. The growth rate of the Mg_xZn_(1-x)O alloy films was determined using spectroscopic ellipsometry. The crystal structures of the films before and after thermal treatment were analyzed using x-ray diffraction. In addition, the optical properties of the Mg_xZn_(1-x)O with different Mg concentrations were analyzed using UV-vis absorption spectroscopy and the electrical properties were evaluated using mercury probe current-voltage measurements. The thermal stability of the conductivity and structure of the Mg_xZn_(1-x)O films were studied as well. The system will be compared with Al doped ZnO system fabricated by ALD, to illustrate the conduction mechanism in doped ZnO synthesized by ALD process.