The paper contains an analysis of the results of experiments on obtaining radiative structures based on gallium antimonide, formed by the method of thermal melt migration in a semiconductor matrix. The epitaxial process modes within the selected range were optimized for such parameters as the wavelength corresponding to the fundamental transition, a small lattice discrepancy, a small discrepancy in the coefficients of thermal expansion of the growing TP and the matrix. An original effect is described - an increase in the solubility of the Bi content in solid solutions, isoperiodic binary compounds A3B5 under conditions of a gradient temperature field. This effect allows a wide variation in the optical parameters of the element base of instruments based on solid solutions of GaSbBi / GaSb. The mechanisms of the generation of dislocations in a crystallized solid solution and the features of electrophysical and photoelectric parameters are analyzed. A structural solution of a light-emitting diode with strip geometry is proposed.
Keywords: solid solutions, recrystallization, gradient liquid-phase epitaxy, thermomigration, indium antimonide-bismuthide, melt thickness, temperature gradient, components, growth coordinate, epitaxial layers
In this paper, the modeling of phase equilibria in multicomponent systems of A3B5 compounds was carried out and the compositions of the liquid phase equilibrated with a given solid solution were calculated. A model of excess thermodynamic functions is used, which takes into account the formation of associates in the melt near the solidus temperatures. The developed algorithm allows solving a direct problem (in which the input parameters are the growth temperature of the layers and the composition of the solid phase corresponding to the expected instrument characteristics) and the inverse problem (the growth temperature and composition of the solid solution are sought for the given liquid phase). The limiting concentrations of the alloying components, arsenic and bismuth, are determined. The structural and electrophysical characteristics of multicomponent semiconductor A3B5 heterosystems are discussed, the solid solutions of which crystallize from the liquid phase in a gradient thermal field. The mechanism for introducing impurities into the lattice of epitaxial layers of multicomponent solid solutions is described for the first time. With an increase in the thickness of the crystallizable film, the thermodynamically equilibrium substitution by antimony bismuth atoms is completed and the introduction of Bi atoms into the interstices takes place. The interaction of neighboring atoms with the valence electron shells of Bi becomes more symmetrical, which causes an increase in concentration. The concentration of film defects near its rear surface also increases. The obtained values of electrophysical parameters make it possible to draw a conclusion about the instrumental suitability of the materials under study.
Keywords: solid solutions, mesostructure, antimonide, alloying, liquid phase, phase transformations, binary compounds, associates, lattice constant, multicomponent systems