Diameter-dependent thermopower of Bi nanowires

We present a study of electronic transport in individual Bi nanowires of large diameter relative to the Fermi wavelength. Measurements of the resistance and thermopower of intrinsic and Sn-doped Bi wires with various wire diameters, ranging from 150-480 nm, have been carried out over a wide range of temperatures (4-300 K) and magnetic fields (0-14 T). We find that the thermopower of intrinsic Bi wires in this diameter range is positive (type-p) below about 150 K, displaying a peak at around 40 K. In comparison, intrinsic bulk Bi is type-n. Magneto-thermopower effects due to the decrease of surface scattering when the cyclotron diameter is less than the wire diameter are demonstrated. The measurements are interpreted in terms of a model of diffusive thermopower, where the mobility limitations posed by hole-boundary scattering are much less severe than those due to electron-hole scattering.Comment: 32 pages, 12 figures. Previous version replaced to improve readabilit

Effect of microwave irradiation on radiative recombination of GaAs

The paper considers the impact of powerful short-term microwave radiation (f= 2.45 GHz) on the defect states of GaAs monocrystals by investigating the luminescence spectra in a domain of 0.6–2.5 μm at 77 K. It has been found experimentally that microwave treatment affects the luminescence characteristics of crystals due to variation of concentration of centers of radiative and nonradiative recombination. The results of the inquiries show advantages of application of microwave radiation in technological processes for modification of the impurity-defect subsystem of semiconductor materials

The impact of microwave radiation on radiative recombination of CdS

The paper considers the impact of a powerful short-term microwave radiation (f= 2.45 GHz) on defect states of CdS monocrystals with the aid of investigation of the luminescence spectra in a domain of 0.6–2.5 μm at 77 K. It has been found experimentally that the microwave processing affects the luminescence characteristics of the crystals because of a change in concentration of cation vacancies (centers of photosensitivity) and in concentration of centers of fast (nonradiative) recombination. The results of the investigations point to the prospects in applying the microwave radiation in technological processes for the control of photosensitivity and of the luminescence spectra of cadmium chalcogenide