The application of new zirconium precursors for the fabrication of ZrO2 and ZrN thin films by metalorganic chemical vapor deposition (MOCVD) is presented. The all-nitrogen coordinated Zr precursors exhibit improved thermal properties for vapor phase fabrication of thin films. The growth of ZrO2 thin films was realized by the combination of the Zr complex with oxygen, while the formation of ZrN thin films was achieved for the first time employing a single source precursor (SSP) approach. This was enabled by the presence of nitrogen containing ligands which contributes to the formation of the ZrN phase without the need for any additional nitrogen source in contrast to classical film growth processes for ZrN thin films. In the first step the newly developed precursors were evaluated thoroughly for their use in MOCVD applications, and in the next step they were utilized for the growth of ZrO2 and ZrN thin films on Si(100) substrates. Polycrystalline ZrO2 films that crystallized in the monoclinic phase and the fcc-ZrN films oriented in the (200) direction were obtained, and their structure, morphology, and composition were analyzed by a series of techniques. This work shows the potential of tuning precursors for vapor phase fabrication of Zr containing thin films with a goal of obtaining two different classes of material systems (ZrO2 and ZrN) using one common precursor.

Structural and optical properties of Si-doped as well as nominally undoped GaInP epilayers grown on Germanium substrates by metal-organic chemical vapor deposition have been investigated by high resolution transmission electron microscope and photoluminescence (PL). Si incorporation results in an increased inner band PL transition and a blue shift of PL energy with increasing temperature, which arises from the trapping states around Ge-GaInP interface due to Ge diffusion to GaInP epilayer as well as Si doping. For the inter band PL transition, a competition between the emission processes near the band edge and in the ordered GaInP domains is responsible for the inverted S shape temperature dependence of PL peaks. By analyzing the time-resolved PL results, we attribute this emission near the ordered states to the localized states due to the potential fluctuation, which is induced by the compositional inhomogeneity of Ga and In in the partially ordered GaInP.

To remove NO in flue gas, complex solution denitration is one of the most effective methods at room temperature. NO removal efficiency is related to the concentration of metal ions and ligands in the absorption solution. The experiments to remove NO in simulated flue gas were carried out by using iron complexation with EDTA disodium salt and sodium citrate as ligands. The NO removal efficiency was determined by mixing ammonium ferrous sulfate, disodium EDTA, and sodium citrate in various ratios. The experimental results revealed a 1:1:1 ratio as optimum for NO removal efficiency and cost-effectiveness of the process. By reducing and regenerating the absorption solution with zinc particles, the regeneration efficiency of Fe­(II)­L (L represents an amino carboxylic acid ligand) is above 70%, and the NO absorbed by the iron complex is reduced to form nitrogen and ammonium salt. The effects of different factors on the NO removal efficiency during the spraying process were investigated. The optimum conditions of absorption, i.e., a concentration of absorption solution of 0.05 mol/L, a temperature of 45 °C, a liquid–gas ratio of 10, and a pH of 6, were established. Under these conditions, the removal efficiency of nitrogen oxides was as high as 85%. The experiment confirmed that the NO removal efficiency is closely related to the concentration of Fe­(II)­L in the absorption liquid, and the removal efficiency decreases as the concentration of Fe­(II)­L in the absorption liquid decreases.

Metal‐organic (MO)CVD of ZrO2 thin films is performed using the precursor [Zr(NMe2)2(guan)2] (guan = η2‐(iPrN)2CNMe2) as the Zr source, together with oxygen. Film deposition is carried out on both Si(100) and glass substrates at various deposition temperatures. The resulting films are characterized by X‐ray diffraction (XRD) and atomic force microscopy (AFM) for investigating the crystallinity and morphology, respectively. Optical properties are measured by ellipsometry and UV‐vis on Si substrates and glass substrates, respectively, showing a high average refractive index of 2.14 and transmittance of more than 80% in visible light for the film deposited at 500°C. The potential of ZrO2 thin films as gate dielectrics is verified by carrying out capacitance‐voltage (C‐V) and current‐voltage (I‐V) measurements. Dielectric constants are estimated from the accumulation capacitance, and found to be in the range 12 ‐ 19 at an AC frequency of 1 MHz, and a leakage current of the order of 10−6 A cm−2 at the applied field of 1 to 2 MV cm−1 is measured for the films deposited at temperatures from 500 to 700°C. The low leakage current and high dielectric constant implies the good quality of the film, relevant for high‐k applications. The hardness of the film ranges from 4.2 to 6.3 GPa for the 400 nm thick film, as determined by nano‐indentation measurements. The optimum dielectric and hardness is found for the film deposited at 600°C, while the highest refractive index is found to be 2.14 for the film deposited at 500°C, due to higher density of the layers.