Features of the Electrical Properties of Heterojunctions n-GaAs-p-(GaAs)1 - x - у(Ge2)x(ZnSe)y
The optimal technological conditions for growing multicomponent epitaxial films of solid solutions (GaAs)1 - x - y(Ge2)x(ZnSe)y with specified physical properties by liquid-phase epitaxy have been determined. It has been established that the above conditions for growing thin films from a tin solution-melt at temperature intervals of 730-630, 650-550 °С with a substrate cooling rate of 1 deg/min are the most optimal. In this case, the films had a thickness of 10 μm and p-type conductivity. For ohmic contacts to such semiconductor solid solutions, Sn, Au, In, (In-Ga) and (Ge-Ag) alloys were used. It was determined that the mobility of current carriers depends on the composition, the structural perfection of the epitaxial layers and the ionization energy of the atoms of the constituent components have values of 0.19, 0.07, 0.029 eV. It has been established that in heterostructures of the n-GaAs-p-(GaAs)1 - x - y(Ge2)x(ZnSe)y type, obtained at Т = 7500 °С, the current transmission is determined by tunneling-recombination, and in the samples obtained at Т = 7300 °С, by currents limited volume charges. It was also determined that a region with a higher resistivity is formed at the heterointerface, the thickness of which, depending on the growth conditions of thin films, is from 0.2 to 0.5 μm.