Papers by Keyword: Charge Carriers

Abstract: Analytical expressions are obtained for the wave functions and the energy spectrum of charge carriers in the β-HgS nanolayer of a cylindrical core/shell/shell β-CdS/ β-HgS/ β-CdS nanocomposite in the presence of a strong lateral uniform electrostatic field. It is shown that, under the influence of an external field, the position of the chemical potential of the electron-hole subsystem at absolute zero shifts to the bottom of the conduction band of the sample. The displacement value is determined by the intensity of the external field and increases linearly with increasing field. The concentration, internal energy, and heat capacity of the electronic subsystem of the β-HgS layer in the presence of a field are compared with similar values in the absence of a field. Calculations show that under identical conditions, the presence of an external field leads to an increase in the carrier concentration, which in turn leads to an increase in the internal energy and heat capacity of the system of electrons and holes in the layer.

Abstract: Design and development of nanostructure of titanium dioxide (TiO₂) assemblies has gained significant scientific interest and become the most studied material as it exhibits promising functional properties. Nevertheless, formation of TiO₂ nanocomposite thin film, especially WO₃-loaded TiO₂ nanotubes without bundling is essential for high efficiency in many potential applications, including photocatalytic oxidation related applications, solar cell related applications, electrochromic devices and sensing related applications. Thus, this chapter aims to summarize on the development of an efficient WO₃-loaded TiO₂ nanotubes catalyst for the improving the performance for charge carriers transportation and extended the spectral response of TiO₂ to visible spectrum. In fact, coupling TiO₂ with W⁶⁺ species will lead to an additional electronic state in the band-gap of nanocomposite thin film, which in turn affect a change in the electronic and functionality of TiO₂ itself. As a result, band gap narrowing effects could expand the range of excitation light to the visible region and provide sites that slow down the recombination of charge carriers. To bring more TiO₂ related applications to the point of commercial readiness and viability in terms of performance and cost, substantial research on the development of high efficient nanocomposite thin film (WO₃-TiO₂) is necessary. In this chapter, different synthesis strategies and research findings for WO₃-TiO₂ nanocomposite thin film as well as its prospects in potential applications will be reviewed in detail.

Abstract: A microscopic mechanism of the self-formation of a dense pore system in the porous silicon is proposed. According to it, the process of porous silicon self-formation is dictated by the laws of dynamics for a charge carriers system. The proposed mechanism is proved by the results of computer simulation. The values of inter-pore separation distance in p-type based porous material and anodization current threshold density are evaluated; the dependence of an inter-pore separation distance on the carriers concentration, close to n^-1/2, is predicted.