On the Structural and Optical Properties of Lead Selenide Nanolayers

Autor: Pashaev, Arif M., Davarashvili, Omar I., Enukashvili, Megi I., Akhvlediani, Zaira G., Bychkova, Larisa P., Gulyaev, Revaz G.
Zdroj: Advanced Materials Research; September 2014, Vol. 1025 Issue: 1 p831-836, 6p
Abstrakt: It was revealed that, according to the analysis by the half-width of the X-ray lines of reflection planes (200) and (600), the sizes of subgrains in the lead selenide nanolayer ~70 nm thick made up 30-45 nm. Disorientation between the subgrains of the order of the ten thousandth of a minute and the deformation (strain) in the layer was determined by the mismatch between the layer and the substrate. It is shown that the forbidden gap width Eg of the same PbSe nanolayer determined by analyzing the optical transmission spectra by two types of straightening f (hν) and (hν)2=f (hν) coincided and made up 0.445 eV, which exceeded Eg of the unstrained PbSe layer by 0.16 eV. The total contribution of quantum effects at the given subgrain sizes and degeneracy of current carriers is less than 0.03 eV, and generally the change in the forbidden gap width was associated with deformation. Key words: dispersion, deformation, disorientation between subgrains, optical transmission, forbidden gap width.
Databáze: Supplemental Index