Title :
Optical and photoluminecsence properties of powdered silica aerogel ar-SiOx
Author :
Karlash, Anna ; Ivanov, Ivan
Author_Institution :
Fac. of Radiophys., Electron. & Comput. Syst., Taras Shevchenko Nat. Univ. of Kyiv, Kiev, Ukraine
Abstract :
Optical and photoluminescent properties of powdered silica aerogel ar-SiOx have been investigated using FTIR spectroscopy and photoluminescence lifetime spectroscopy. Powdered silicagel was prepared from sodium silicate water solution using sol-gel technique. FTIR spectra revealed the presence of numerical hydroxyl groups such as bonded Si - OH and non-bonded -OH groups which determines oxidative properties of the material and confirmed that investigated material consists of two phases: stoichiometric SiO2 and non-stoichiometric SiOx. The intense photoemission was detected in blue-green region with stipulated peaks at 1.9, 2.0, 2.2 and 2.6 eV. It was shown that emission properties of powdered silica aerogel ar-SiOx caused by the presence of numerical oxygen defect centres. Optical sensor response of powdered silica aerogel under treatment of liquid adsorbate (ethyl alcohol water solutions) have been revealed. The reversible PL quenching has been observed in the wide range of ethyl concentration. Maximum sensor response of ar-SiOx samples was estimated to be Sm1=1.2 for 96% ethyl alcohol solution and Sm2=2.1 for pure water.
Keywords :
Fourier transform infrared spectra; aerogels; photoluminescence; silicon compounds; sol-gel processing; FTIR spectroscopy; SiO2; electron volt energy 1.9 eV; electron volt energy 2.0 eV; electron volt energy 2.2 eV; electron volt energy 2.6 eV; ethyl alcohol water solutions; ethyl concentration; numerical hydroxyl groups; optical properties; optical sensor; photoluminecsence properties; photoluminescence lifetime spectroscopy; powdered silica aerogel; powdered silicagel; sol-gel technique; Ethanol; Liquids; Optical sensors; Photoluminescence; Silicon; Silicon compounds; Spectroscopy; FTIR transmission spectroscop; PL lifetime spectroscopy; powdered silica aerogel; sensor responce;
Conference_Titel :
Electronics and Nanotechnology (ELNANO), 2015 IEEE 35th International Conference on
Conference_Location :
Kiev
DOI :
10.1109/ELNANO.2015.7146845