Generalized Muller-Kern formula for equilibrium thickness of a wetting layer with respect to the dependence of the surface energy of island facets on the thickness of the 2D layer

Experimental results indicate a particular importance of such a value as the equilibrium thickness of the wetting layer during epitaxial growth according to the Stranski–Krastanow mechanism in systems with a lattice mismatch. In this paper the change in free energy during the transition of atoms from the wetting layer to the island in such systems is considered. Recent experimental results also show that the surface energy of the island's facets depends upon the thickness of the deposited material. So, in this paper the equilibrium thickness of the wetting layer, at which transition from 2D to 3D growth becomes energetically favorable, is calculated with the assumption that the specific energy of the island's facets depends upon the wetting layer thickness. In this approximation a new generalized Muller–Kern formula is obtained. As an illustration of the proposed method, an example of a numerical calculation according to the new formula for the material system of germanium on a silicon (001) surface is given. The result for the found equilibrium thickness of the wetting layer is rather unexpected since it differs from the value obtained in the bounds of the traditional Muller–Kern model

Dark current and detectivity of multilayer Ge/Si photodetector with quantum dots

Since the demonstration of molecular beam epitaxy which widened the ability to establish more applications based on semiconductor materials, and after the big success of quantum well structures for infrared detection, a lot of attention has been paid to the quantum discoveries [1], this has stimulated the development of quantum dot structures and its ability for infrared detection. In the past decades the quantum dot structure has proven their efficiency in comparison to other types of semiconductors and they have become an interesting field for research because of their high photoconductive gain, low dark current and the ability to operate under increasing temperature conditions

Analysis of the 7x7 to 5x5 superstructure transition by RHEED in the synthesis of Ge on Si (111) in an MBE installation

In this paper, we consider the 7x7 to 5x5 superstructure transition during the synthesis of Ge epitaxial layers on a Si (111) surface in its temperature range from 250 to 700 °C. This transition is investigated by reflection high-energy electron diffraction (RHEED). As a result, the dependences of the critical thickness of the 7x7 to 5x5 superstructure transition on the substrate temperature are obtained for the first time

Kinetics of epitaxial formation of nanostructures by Frank-van der Merwe, Volmer-Weber and Stranski-Krastanow growth modes

Nowadays, two-dimensional crystals (2D materials) and structures with quantum dots (0D materials) are considere