Papers by Author: Y.N. Drozdov

Abstract: t is reported about fabrication by laser deposition in a gaseous environment of epitaxial layers of ferromagnetic semiconductors GaMnSb and InMnSb. Investigations of x-ray diffraction and Raman scattering showed reasonably good crystal quality of GaMnSb and InMnSb layers. Magnetic properties were investigated by magneto-optical transversal Kerr effect and Hall effect. It is established, that GaMnSb layers are ferromagnetic at room temperature. In contrast, InMnSb samples demonstrate the ferromagnetic properties only at low temperatures (< 70 K).

Abstract: Circularly polarized electroluminescence from light-emitting diodes based on InGaAs/GaAs heterostructures with adjacent ferromagnetic delta-doped layer has been investigated. It was found that delta-layer placed near (at 2-10 nm) the quantum well (QW) causes circular polarization of its electroluminescence due to an s,p-d exchange interaction between holes in the quantum well and Mn ions in the delta-layer. The dependence of circular polarization degree on main technology parameters is discussed.

Abstract: Terahertz-range photoluminescence from silicon-germanium crystals and superlattices doped by phosphor has been studied under optical excitation by radiation from a mid-infrared CO2 laser at low temperature. SiGe crystals with a Ge content between 0.9 and 6.5 %, doped by phosphor with a concentration optimal for silicon laser operation, do not exhibit terahertz gain. On the contrary, terahertz-range gain of ~ 2.3 - 3.2 cm-1 has been observed for donor-related optical transitions in Si/SiGe strained superlattices at pump intensities above 100 kW/cm2.