Nanocomposites and nanomaterials
Luminescent properties of porous silicon carbide
 I.V. Gavrilchenko1, Y.S. Milovanov1, S.V. Gryn2, S.A. Alekseev2, I.I.Ivanov1, A.N. Zaderko1, A.G. Shkavro1, V.A. Skryshevsky1
1 Institute of High Technologies, Taras Shevchenko National University of Kyiv, 01601 Volodymyrska str. 64, Kyiv, Ukraine. 
E-mail: ir.gavril11@gmail.com
2 Faculty of Chemistry, Taras Shevchenko National University of Kyiv, 01601 Volodymyrska str. 64, Kyiv, Ukraine.

The luminescent properties of SiC nanostructures have been widely studied over the past 20 years due to the potential use of such structures as efficient nanoscale light emitters [1]. According to [2], the nature of photoluminescence (PL) is explained by the model of quantum confinement. The PL intensity is proportional to the number of photons emitted from the surface, which, in turn, depends on the porosity of the surface of the porous SiC substrates. Consequently, the photoluminescent properties of porous SiC can be improved by optimizing surface characteristics such as specific surface area [2]. 
This paper presents the results of structural photoluminescent studies of free-standing porous SiC layers formed from a SiC plate by electrochemical etching. Structural and morphological properties of porous SiC were analyzed using SEM and Raman spectra. The obtained photoluminescent properties are in good agreement with the above results of SEM, TEM and Raman studies, since the obtained material consists of crystalline 3C-SiC covered with an amorphous surface layer, which probably consists of the chemisorbed oligomeric compound called carbon fluorooxide (CFO), incorporating defects within 3C-SiC.  
Photoluminescence of porous layers was characterized by an emission band in the visible region, in which three peaks can be distinguished. The nature of the low-energy peak is explained by the electron-hole recombination at some localized states; the other peak is related to the CFO; the high energy peak can be explained by SiC nanocrystallites.

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2. N. Naderi, M. R. Hashim, K. M. A. Saron, and J. Rouhi, ‘Enhanced optical performance of electrochemically etched porous silicon carbide’, Semicond. Sci. Technol.-2013.- vol. 28, №2, P. 025011.