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R. S. Маdаtоv, А. S. Alеkpеrоv, and А. E. Nаbiyеv
«Influence of Impurity Nd Atoms on the Photoluminescence Spectrum of a Layered Single Crystals \(Ge_{0.995}Nd_{0.005}S\)»
509–518 (2018)

PACS numbers: 71.35.-y, 72.40.+w, 73.50.Pz, 78.20.Ci, 78.55.Hx, 78.56.-a, 79.60.Jv

Extensive use of layered crystals in optoelectronics significantly increases interest in these materials in recent years. The specific feature of these crystals is the sharp anisotropy of physical properties. Anisotropy manifests itself in the optical and magnetic properties of the substances. Despite all the advantages, the physical properties of layered crystals, including GeS crystals, were studied casually. Recently, a nanostructure similar to a carnation was fabricated from layered GeS crystal, and large amounts of energy can be accumulated with the use of solar panels composed of them. The field transistor created on the base of GeS crystal with a thickness of ??28 nm overcomes its analogues due to its flexibility and multifunctionality. All this suggest that layered GeS single crystal as the main research object can be used to produce microprocessors, nanostructures capable meeting modern requirements. The study of the spectral distribution of photoconductivity of layered GeS single crystal shows that this crystal is semiconductor substance photosensitive in the visible and near-infrared ranges of the spectrum. At the same time, there are opportunities to create optoelectronic devices on the base of germanium monosulfide. Since the GeS crystal is a direct-band-gap semiconductor, in its photoluminescence spectrum, radiative electron transitions in the near-infrared range are detected. In modern electronics, rare earth metals (REM) are used to obtain more intense radiative electron transitions. Exactly, complicated complexes created by REM have the ability to create radial recombination centres in the different binary compounds, including the GeS matrix, in a wide temperature range. Studies show that, in the most of the layered crystals, the role of exciton phenomena in the formation of photoluminescence spectrum and the optical absorption is significant. The aim of this research is to investigate the role of the exciton phenomena in photoconductivity as well as in the formation of radiative electron transitions in layered GeS single crystals (GeS:Nd) doped with Nd atoms, and to correlate the obtained results with the optical absorption spectrum.

Keywords: layered single crystals, rare-earth metals, exciton states, photoluminescence, optical absorption, exciton–impurity complexes, recombination radiation

https://doi.org/10.15407/nnn.16.03.509