Abstract: In case of semiconductor samples, the method enables the determination of the charge carrier lifetime and crystal defect concentration related to the recombination defect centers present in the material based on photomodulated reflection (PMR) measurement operating in the quasi-static modulation frequency range. The defect centers present in the basically single-crystal semiconductor sample (M1) can be of intrinsic or extrinsic origin, typically electrically active de-feet sites created by the implantation of low-mass—H+, He+—high-energy ions, or impurity atoms. e.g., metal contaminants introduced during other technological steps. The method can be used in all cases where the crystal defect concentration is typically in the ppb-ppm range, its depth distribution is almost uniform, and the size of the excitation/analyzing laser spot in the PMR measurement is significantly smaller than the thickness of the zone containing the crystal defects.

Abstract: An apparatus for universal water treatment with cylindrical housing and rotating ring-baskets, in which the housing is provided with untreated water inlet and purified water outlet stubs and the rotating filter baskets contains a back-washing chamber for regeneration of the baskets. The rotary filter baskets contain also an annular coagulating space formed in the cylindrical housing connected to the untreated water inlet stub. The rotating filter baskets are arranged uniaxially with the coagulation space and with each other. The filter baskets may be arranged within or above each other. Several filter beds are arranged in the filter baskets separated from each other and provided with independent back-washing chamber. The filter beds are arranged between cylindrical, perforated partition walls.