The paper presents results for zinc oxide films grown at low temperature regime by Atomic Layer Deposition (ALD). We discuss electrical properties of such films and show that low temperature deposition results in oxygen-rich ZnO layers in which free
carrier concentration is very low. For optimized ALD process it can reach the level of 10^15 cm-3, while mobility of electrons is between 20 and 50 cm2/Vs. Electrical parameters of ZnO films deposited by ALD at low temperature regime are appropriate for constructing of the ZnO-based p-n and Schottky junctions. We demonstrate that such junctions are characterized by the rectification ratio high enough to fulfill requirements of 3D memories and are deposited at temperature 100degC which makes them appropriate for deposition on organic substrates.
Optical and magneto-optical properties of ZnCoO films grown at low temperature by Atomic Layer Deposition are discussed. Strong wide band absorption, with onset at about 2.4 eV, is observed in ZnCoO in addition to Co-related intra-shell transitions.
This absorption band is related to Co 2+ to 3+ photo-ionization transition. A strong photoluminescence (PL) quenching is observed, which we relate to Co recharging in ZnO lattice. Mechanisms of PL quenching are discussed.
We report on the structural, electrical and magnetic properties of ZnCoO thin films grown by Atomic Layer Deposition (ALD) method using reactive organic precursors of zinc and cobalt. As a zinc precursor we applied either dimethylzinc or diethylzinc
and cobalt (II) acetyloacetonate as a cobalt precursor. The use of these precursors allowed us the significant reduction of a growth temperature to 300oC and below, which proved to be very important for the growth of uniform films of ZnCoO. Structural, electrical and magnetic properties of the obtained ZnCoO layers will be discussed based on the results of SIMS, SEM, EDS, XRD, AFM, Hall effect and SQUID investigations.
We demonstrate that room temperature ferromagnetic response (RT FR) of ZnCoO films grown at low temperature by the Atomic layer Deposition (ALD) method is due to Co metal accumulations at the ZnCoO/substrate interface region. The accumulated experime
ntal evi evidences allow us to reject several other explanations of this effect in our samples, despite the fact that some of them are likely to be responsible for the low temperature FM in this class of the material.
Optical properties of ZnMnO layers grown at low temperature by Atomic Layer Deposition and Metalorganic Vapor Phase Epitaxy are discussed and compared to results obtained for ZnMnS samples. Present results suggest a double valence of Mn ions in ZnO l
attice. Strong absorption, with onset at about 2.1 eV, is tentatively related to Mn 2+ to 3+ photoionization. Mechanism of emission deactivation in ZnMnO is discussed and is explained by the processes following the assumed Mn 2+ to 3+ recharging.
Optical and magneto-optical properties of ZnMnO films grown at low temperature by Atomic Layer Deposition are discussed. A strong polarization of excitonic photoluminescence is reported, surprisingly observed without splitting or spectral shift of ex
citonic transitions. Present results suggest possibility of Mn recharging in ZnO lattice. Strong absorption, with onset at about 2.1 eV, is related to Mn 2+ to 3+ photo-ionization. We propose that the observed strong circular polarization of excitonic emission is of a similar character as the one observed by us for ZnSe:Cr.
