Electrical and optical properties of tin-doped CdO films deposited by atmospheric metalorganic chemical vapor deposition

Discovery-based design of transparent conducting oxide films

Epitaxial growth of both pure and doped CdO thin films has been achieved on MgO (111) substrates using pulsed laser deposition. A maximum conductivity of 42 000 S/cm with mobility of 609 cm2/V s is achieved when the CdO epitaxial film is doped with 2.5% Sn. The pure CdO epitaxial film has a band gap of 2.4 eV. The band gap increases with doping and reaches a maximum of 2.87 eV when the doping level is 6.2%. Both grain boundary scattering and ionized impurity scattering are found to contribute to the mobility of CdO films.

Highly conductive epitaxial CdO thin films prepared by pulsed laser deposition

The bulk of developmental work on transparent conducting oxides (TCOs) has been somewhat empirical. This statement applies both to more familiar materials such as indium tin oxide (ITO) and to less-well-known materials that have emerged in recent years. In this article, we place a greater emphasis on more fundamental research. Our eventual goal is to gain a thorough understanding of these materials, their potential for further improvement, whether or not they suggest new and potentially superior materials, and the way their properties are influenced by structural and other issues. We also hope to provide guidelines to other researchers working in this area. We have investigated films of cadmium oxide (CdO), cadmium stannate (Cd2SnO4 or CTO), and zinc stannate [Zn2SnO4 (ZTO)]. The CdO was prepared by chemical-vapor deposition, whereas the stannates were prepared by rf sputtering. In both cases, Corning 7059 glass substrates were used. However, some depositions were also made onto tin oxide, which had a pro...

Search for improved transparent conducting oxides: A fundamental investigation of CdO, Cd2SnO4, and Zn2SnO4

Transition metal oxides – Thermoelectric properties

Transparent conducting cadmium oxide (CdO) films have been deposited by spray pyrolysis. The film thicknesses have been determined using Rutherford backscattering spectrometry. X-ray diffraction measurements show that the films are polycrystalline with a preferential orientation along the (111) diffraction plane and the lattice parameter has been calculated. The dislocation density and strain have also been evaluated. The films possess a transmittance of about 75% in the visible and near-infrared region. The refractive index is found to vary between 1.68 and 2.84 in the wavelength range 500-1500 nm. The values of indirect and direct bandgaps obtained are 1.98 and 2.32 eV respectively. Hall effect measurements have been carried out in the temperature range 304-349 K. Resistivity, carrier concentration and mobility of the films at room temperature have been evaluated as 6.6*10-5 Omega m, 1.4*1025 m-3 and 0.68*10-2 m2 V-1 s-1 respectively. Thermoelectric power values from thermoelectric power measurements carried out in the temperature range 304-376 K have been found to be about 19.7-89 mu V K-1. Laser damage studies performed at a wavelength of 1.06 mu m indicate that the films possess a damage threshold density of about 2.37*104 J m-2.

https://iopscience.iop.org/article/10.1088/0268-1242/9/10/013/pdf

Characterization of transparent conducting CdO films deposited by spray pyrolysis

Structural characterization of cadmium oxide thin films deposited by spray pyrolysis

Thin films of cadmium oxide have been produced by dc reactive magnetron sputtering in nitrogen and oxygen atmosphere. The structural, optical, and electrical characterization of these films are investigated. Structural analysis indicates that the films are polycrystalline and cubic. Composition analysis by Rutherford backscattering spectrometry has been made and it is found that the films contain excess cadmium and deficient oxygen. It is observed from the optical properties that the films possess a transmittance of about 85% in the visible and near infrared regions of the spectrum and direct bandgap values in the range 2.50 to 2.68 eV for films of thicknesses 146 to 177 nm. Electrical measurements point out that the films have resistivity, carrier concentration, and mobility in the range 2.65 to 6.64 × 10-6 Ωm, 1.60 to 2.35 × 1026 m-3, and 57.65 to 100.48 × 10−4 m2 v−1 s−1 respectively.

Magnetron sputtered transparent conducting CdO thin films

Transparent conducting cadmium oxide films are prepared by the spray pyrolytic technique. The dependence of structural, optical, and electrical properties on the film thickness is investigated. X-ray diffraction studies confirm the polycrystallinity of the films and the films show preferential orientation along the (200) plane. The crystallite size and the dislocation density are also determined from the above patterns. The films show about 70% transmittance in the wavelength range 750 to 850 nm and the values of band gap and refractive index are in the order 2.35 to 2.50 eV and 1.95 to 2.65, respectively. Hall measurements indicate that the films are n-type, having carrier concentration ≈ 1026 m−3 and mobility (17.5 to 19) × 10−4m2/Vs.

K. Gurumurugan

Papers

Characterization of transparent conducting CdO films deposited by spray pyrolysis

Structural characterization of cadmium oxide thin films deposited by spray pyrolysis

Magnetron sputtered transparent conducting CdO thin films

Structural, optical, and electrical properties of cadmium oxide films deposited by spray pyrolysis

DC reactive magnetron sputtered CdO thin films