Band structure and model of the paraelectric structure of the Sn2P2S6 crystal

Gain Spectrum for the In4Se3Crystal with a Non-Standard Dispersion Law of Charge Carriers

“…The dispersion laws for electrons and holes exhibit a low--energy non-parabolicity due to the presence of the four--power terms of the wave vector k. A consequence of this fact is a peak-like density of states function [5]. These peculiarities were observed for the first time in calculations of the band structure of In 4 Se 3 crystal by the semiempirical pseudopotential method [6], confirmed both by the ab initio band structure calculations [1] in the framework of density functional theory (DFT), and experimentally [2,3]. Such a placement of the band extrema favors the radiative recombination of charge carriers, which is the subject of theoretical investigation of this paper.…”

Energy States in Superlattices Connected With Incommensurate Phase Presence

“…Nevertheless, one can state that the proposed model is capable of quite good qualitative description of the considered transition and can be used as the first step approximation of electron subsystem behavior in modulated structures. The quantum effects obtained can lead to an unusual behavior of several kinetic and optical properties, namely to the realization of the dark conductivity according to Mott's law in Sn 2 P 2 S 6 , the memory effect in incommensurate phase in the Sn 2 P 2 Se 6 crystal [12], the phenomenon of a long-time photoconductivity relaxation [13], an unusual behavior of the optical absorption edge in the ferroelectric and incommensurate phase. Really, the redistribution of the charge carriers on the created energy levels and the abrupt growth of the density of electron states that lead to the intensification of the electron inhomogeneity are possible.…”

“…Since the space period of the potential in the equation (1) is equal to L, we will be interested only in π-periodical solutions of the equation (5). It should also be noted that because of the invariance of the expression in the brackets under space inversion, the solutions will possess the definite parity.…”

“…It should also be noted that the Sn 2 P 2 Se 6 ferroelectrics have a comparatively wide energy gap (E g0 ∼ 1.85 eV [5]). Thus, the investigated herein transport properties are mainly related to the photoexcited nonequilibrium charge carriers.…”

Parameters of an Unique Condenson State in the Structure of the In4Se3Crystal

“…The scale transformation gives a possibility to analyze our issue for three cases of space dimension (d = 1, 2, 3 [4]). In the case of a 3D-crystal (d = 3) and anisotropic scale transformation, the ψ function takes the form [5,6]:…”