Electronic structure calculation of Si_1−xSn_x compound alloy using interacting quasi‐band theory

Abstract

We investigate energy band structures of the Si1−xSnx compound alloy in the zincblende structure using interacting quasi‐band (IQB) theory. We first extend the IQB theory for four‐element compounds and subsequently calculate the electronic structures of the virtual Si1−xSnxSi1−ySny alloy where x = y. Diagonalizing a 20 × 20 non‐Hermitian Hamiltonian matrix using sp3s* empirical tight‐binding model with parameters obtained for the Si, Sn, and SiSn (zincblende) crystals, we obtain the electronic energy spectrum of the Si1−xSnx alloy for arbitrary x. Comparing the band structures, we reveal that the indirect–direct gap crossover in Si1−xSnx alloys occurs around x = 0.67 with Eg = 0.87 eV. Calculated Sn concentration dependence of energy gaps in Si1−xSnx alloy.

Electronic structure of (ZnO)1−x (InN) x alloys calculated by interacting quasi-band theory

“…the IQB theory, the absolute positions of the site energies are crucial. In our previous study on alloys, such as InGaN, [12][13][14] the N atom was common to both InN and GaN. In this scenario, the site energies ,…”

“…11) This method is applicable to various alloys with diagonal and off-diagonal randomness, at any concentration. By extending the IQB theory and using the sp 3 s* (sp 3 ) empirical tight-binding model, we then calculated the electronic structures of typical III-V and II-VI semiconductor alloys with both the zincblende 12) and wurtzite structures 13) and successfully described the general behaviour of the concentration dependence of the top of the valence and the bottom of the conduction bands. When calculating the electronic structure of a cation-substituted alloy, for example III 1−x III′ x -V, the only necessaries are the sp 3 s* crystal parameters in the constituent III-V and III′-V semiconductors.…”

“…The calculation procedures are detailed elsewhere. [12][13][14] In this study, we further extend the IQB theory to investigate the electronic structure of (ZnO) 1−x (InN) x , a typical novel hybrid of the alloy systems (II-VI) 1−x (III-V) x . As stated above, we must properly account for the randomness due to the statistical occupation of atoms.…”

Structure and Optical Properties of Co-Sputtered Amorphous Silicon Tin Alloy Films for NIR-II Region Sensor

“…For example, the SiSn crystallization temperature can be reduced with a substitutional Sn content of around 30% [2]. In order to make SiSn alloys suitable for optical application, Masato Oda et al [9] utilized interacting quasi-band (IQB) theory and found that the indirect-direct gap crossover in Si 1−x Sn x occurs around x = 0.67 with Eg = 0.87 eV. There are also many studies on the optical and electrical properties and surface microstructure of SiSn films with an Sn concentration of 10-51% [10][11][12].…”

Electronic structure of Si_{1-x}Sn_x disordered solid solutions

“…Зокрема, кiлька теоретичних робiт передбачають, що перехiд непрямозонний-прямозонний напiвпровiдник у сплавах Si 1−x Sn x вiдбудеться за значень x вiд 0.25 до 0.67 залежно вiд методу розрахунку [2][3][4][5]. Ця вiдмiннiсть у результатах зумовлена, головно, труднощами врахування невпорядкованостi таких систем.…”