Nanograin boundaries and silicon carbide photoluminescence
Journal Title: Semiconductor Physics, Quantum Electronics and Optoelectronics - Year 2017, Vol 20, Issue 3
Abstract
The luminescence spectra of SiC crystals and films with grain boundaries (GB) on the atomic level were observed. The GB spectra are associated with luminescence centers localized in areas of specific structural abnormalities in the crystal, without no reference to the one-dimensional layer-disordering. The zero-phonon part of GB spectra is always within the same energy range (2.890…2.945 eV) and does not fit in the dependence of its position in the energy scale on the percent of hexagonality as in the case of stacking faults (SFi) and deep level (DLi) spectra. The zero-phonon part 2.945…2.890 eV with a fine structure is better observed in crystals with the centers of origin growth of crystal, if ND – NA ~ (2…8)•1016 cm–3, ND ~ (2…7)•1017 cm–3. The edge phonons of the Brillouin zone TA-46 meV, LA-77 meV, TO-95 meV and LO-104 meV are involved in development of the GB spectrum. This spectrum may occur simultaneously with the DLi and SFi ones. The GB spectra also occur after high temperature processing the β-phase (in the 3C-SiC) with appearance of the α-phase. The temperature range of observation is 4.2…40 K. There is synchronous thermal quenching of all elements in the fine structure. The thermal activation energy of quenching is ЕаТ ~ 7 meV.
Authors and Affiliations
S. I. Vlaskina, G. N. Mishinova, V. I. Vlaskin, V. E. Rodionov, G. S. Svechnikov
Keywords
Related Articles
- EP ID EP232882
- DOI 10.15407/spqeo20.03.344
- Views 68
- Downloads 0
Possible method for evaluation of virus, bacteria and yeasts infectivity by optical measurements
The possible method for evaluation of virus, bacteria and yeasts infectivity based on study of their absorption spectra has been proposed. The decrease in the samples infectivity was caused by adding the CeO2 nanoparticl...
An original way to obtain porous Zn(1–x)MgxO thin films by spray pyrolysis technique
Zn(1–x)MgxO thin films with various concentrations of magnesium were deposited using the spray pyrolysis method. The transmittance spectra recorded for all films exhibit maxima exceeding 90%. The band gap energy of the f...
Speckle pattern formation in spatially limited optical systems
The dependences of statistical parameters inherent to speckle patterns on the object roughness and aperture size have been investigated. The experimental results that confirm theoretical dependence quality within the lim...
Surface enhanced imaging and IR spectroscopy of the biological cells on the nanostructured gold film
New approach for optical imaging, structural study and cell cultivation based on the effect of the enhancement of optical signals from biomolecules and biological cells near nanostructured rough gold surface is proposed....
Influence of the composition of (TlGaS2)1–х(TlInSe2)x solid solutions on their physical properties
The single crystals of (TlGaS2)1–х(TlInSe2)х (х = 0…0.5) solid solutions have been grown up. The photoelectric, X-ray dosimetric, dielectric and optical characteristics of the (TlGaS2)1-х(TlInSe2)х solid solutions with v...