B. Solecka

Sonochemical preparation of antimony subiodide

The substantiated isolation of the antimony subiodide (Sb(3)I) is presented for the first time. It has been prepared using elemental Sb and I in ethanol under ultrasonic irradiation at 323 K. Its composition was characterized using X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDAX). The scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) investigations exhibit that the samples are made up of large quantity of nanoparticles with diameters smaller than 20 nm and single crystalline in nature. The interplanar spacings in Sb(3)I that have been determined using powder X-ray diffraction (XRD), selected area electron diffraction (SAED) and HRTEM are very similar. Surprisingly, the registered XRD patterns are identical to the one reported earlier for Sb(4)O(5)I(2).

Influence of acousto-optical modulation of laser radiation on the results of contactless photoelectromagnetic investigations

The contactless photoelectromagnetic (PEM) method of determining carrier lifetimes in semiconductors needs high frequency modulation of laser light. Recently the acoustooptical modulation technique was used for this purpose. In this paper the influence of frequency of acoustooptical modulation on time dependence of intensity of laser light was examined. One can recognize the importance of taking into account in contactless PEM investigations of carrier lifetime the dependence of amplitude of illumination on frequency of laser beam acoustooptical modulation.

Contactless photomagnetoelectric investigations of 2D semiconductors

Background: Applications of two-dimensional (2D) materials in electronic devices require the development of appropriate measuring methods for determining their typical semiconductor parameters, i.e., mobility and carrier lifetime. Among these methods, contactless techniques and mobility extraction methods based on field-effect measurements are of great importance. Results: Here we show a contactless method for determining these parameters in 2D semiconductors that is based on the photomagnetoelectric (PME) effect (also known as the photoelectromagnetic effect). We present calculated dependences of the PME magnetic moment, evoked in 2D Corbino configuration, on the magnetic field as well as on the intensity and spatial distribution of illumination. The theoretical predictions agree with the results of the contactless investigations performed on non-suspended single-layer graphene. We use the contactless PME method for determining the dependence of carrier mobility on the concentration of electrons and holes induced by a back-gate voltage. Conclusion: The presented contactless PME method, used in Corbino geometry, is complementary to the mobility extraction methods based on field-effect measurements. It can be used for determining the mobility and diffusion length of carriers in different 2D materials.