New semiconductors and their possible applications

Using GasSb substrates, epitaxial layers of Al,GayInl_x_ySb and bulk GaP~AsySbt_x_y crystals were investigated. In these alloys three different atoms share a single sublattice in the sphalerite structure. The similar cationic pseudoternaries (A1GaInP or A1GaInAs) cannot be grown by LPE because of large A1 segregation. The anionic types (InPAsSb, GaPAsSb) can be prepared by LPE, but miscibility gaps and strong segregation of P make difficulties. Our A1GaInSb samples have been prepared by the LPE method giving homogeneous in composition p- and n-type layers and p-n junctions, as well. GaPAsSb was prepared as bulk single crystals using transport reactions. Preliminary measurements show that the cationic AlxGayInl_x_ySb pseudoternary with a composition of x = 0.97, y = 0.02 can be applied to developing detectors. These junction-type devices function efficiently in the spectral regions where the Ge photodiodes work. The other, anionic pseudoternary GaP~AsySbt_~_y has shown brilliant photoand cathodoluminescence. The composition of the measured phase was x = 0.36 and y = 0.62. Lattice constant and composition measurements showed that while the cationic alloy composition falls into the indirect band gap region, the anionic luminescent phase is a direct material. This gives a possibility of developing light sources in the visible range.