The results of the experimental study and theoretical simulation of the photoluminescence (PL) spectra of strained germanium microbridges with improved heat sink are reported. It was shown that in the structures under study the main contribution to the PL signal of micro-bridges is provided by the radiative transitions from -valley to the valence band in the whole considered temperature range (from 80 to 300 K). The influence of interference and self-absorption effects on the shape of the PL spectra of Ge microbridges is discussed. It was demonstrated that Ge microbridges with improved heat sink which was achieved due to the adhesion of the bridges to the underlying layers due to capillary forces are not subjected to the additional stretching as the temperature decreases in contrast to the suspended ones. Keywords: SiGe structures, tensile strained Ge, photoluminescence, simulation of the photoluminescence spectra.

The capture times of holes to the ground level of the neutral mercury vacancy in a solid solution of Hg1-xCdxTe during the emission of an optical phonon are calculated. The calculation showed that this process can compete with the capture of holes into small excited states of vacancy centers with the emission of acoustic phonons. Such competition can lead to quenching of lines in the spectrum of vacancy photoluminescence of Hg1-xCdxTe layers with increasing temperature. Keywords: mercury vacancy, optical phonon, non - radiative transition.

Three recombination mechanisms of nonequilibrium carriers in gapless undoped quantum well in HgTe/CdHgTe heterostructure are considered. Dependencies of ensemble-average probability of recombination (inverse of recombination time) on concentration of nonequilibrium carriers for recombination with emission of optical phonons, recombination with emission of two-dimensional plasmons, and radiative recombination have been calculated. Key words: gapless HgTe quantum well, recombination mechanisms of nonequilibrium carriers.