Structural Peculiarities of the (ZnSe)_{1 – x – y}(Ge₂)_x(GaAs_1 – δBi_δ)_y Solid Solution with Various Nanoinclusions

Abstract

Films of substitutional solid solutions (ZnSe)_{1 – x – y}(Ge₂)_x(GaAs_1 – δBi_δ)_y (where 0 ≤ x ≤ 0.725 and 0 ≤ y ≤ 0.638) with various nanoinclusions are grown in the temperature range of 750–650°C near the crystallization point of a bismuth-containing melt solution with a substrate cooling rate of 1 degree/min. A thin-film layer enriched in Ge and GaAs_1 – δBi_δ is formed between the substrate and the surface region. The obtained films with a thickness of 10 μm are of the single-crystal type with (100) orientation and p-type conductivity. They have a sphalerite structure with a lattice parameter of 0.5663 nm. It is found that paired Ge atoms partially replace ZnSe molecules near defects of the matrix lattice of the film, while the remaining atoms form germanium nanocrystals with a lattice parameter of a_Ge = 0.5659 nm and a size of 47 nm at the interfaces between film subcrystallites. It is established that nanoinclusions in the form of quantum wells with dimensions of 43 nm are formed during crystallization in GaAs_1 – δBi_δ compounds near the surface of the film.