Papers by Keyword: p-Type Conduction

Abstract: In this work, we present results about the preparation and characterization of stannous oxide (SnO) thin films. SnO thin films were obtained via thermal evaporation method from SnO₂ powder as source material. These thin films were successfully deposited onto well cleaned glass substrates by thermal evaporation technique. The as deposited thin films were of thickness of 2500 Å and film were post-deposition annealed in air ambient at 400°C for 20 min and 40 min, respectively in a furnace. As-deposited films are highly conductive and p type. The best p-type SnO film annealed at 400 °C for 40 min shows a resistivity of 1.05 Ω·cm and a relatively high hole concentration of 2 × 10¹⁷ cm³ at room temperature. The X-ray diffraction (XRD) patterns of annealed films exhibit a polycrystalline hexagonal wurtzite structure without preferred orientation. The scanning electron microscopy (SEM) image shows the presence of uniformly dispersed spherical in shaped SnO particles. The mean grain sizes (diameter) are calculated to be about 80 and 100 nm for the p-type SnO films prepared at 400 °C for 20 min, and 40 min, respectively. Room temperature photoluminescence (PL) spectra of the SnO film exhibit two emission bands, around the wavelength of 300 nm and 450 nm. All spectra were measured at room temperature.

Abstract: Thin films of a composite of molybdenum disilicide (MoSi₂) and silicon (Si) were fabricated by radio frequency magnetron sputtering using a target made of a powder mixture of MoSi₂ and Si with a Si-to-Mo molar ratio of 1:X (2.0 X 2.5). The Hall coefficients were measured to identify the conduction mechanisms in the thin films. The sign and magnitude of the Hall coefficients revealed that thin films with X = 2.02.2 having a hexagonal crystal structure showed p-type conduction, while the mechanism for the n-type film with X = 2.33 was unknown and that for a composite of hexagonal and an unknown structure with X = 2.3, 2.4 and 2.5 showed mixed conduction.

Abstract: A quantitative elucidation of the void formation in a growing scale with Schottky defects and p-type conduction during high temperature oxidation of metals. The evaluation of the divergence of ionic fluxes indicates that (1) Voids form in the scale preferentially in the vicinity of the metal/scale interface, (2) The volume of voids increases in a parabolic manner, (3) The volume fraction of voids and the scale is independent of time. The comparison between the calculation and the experimentally observed scale microstructure of NiO and CoO confirmed well the validity of the prediction.