| dc.description.abstract | In this work, we use Raman spectra and Photoluminescence spectra to study the polytype structure sorts and luminescence properties of silicon carbide samples, respectively.
Silicon carbide samples will show different phonon mode signals at different wave number positions of Raman spectra due to the various polytype structures, therefore, the polytype structure sorts of silicon carbide samples can be distinguished by Raman spectra. From the experimental results, we can identify that the samples we used are 4H-SiC and 6H-SiC.
By measuring PL spectra, we can know that there are many intrinsic defects in these silicon carbide samples, and we also measured several sharp signals of zero-phonon lines at low temperature, which are caused by the intrinsic defects. From temperature dependent PL spectra, the fluorescent signals come from multiple different defects. Besides, there are other defects also participate in the light emission at different temperature, so that the peak positions of fitting are slightly different. Plot the peak integrated intensity after fitting against the temperature, and fit the graph with Arrhenius equation, then we can get the activation energy of the silicon carbide samples.
At last, we measure the temperature dependent PL spectra and fit the graph to get the activation energy again after doing microwave heating on silicon carbide samples for eight times. Then we compare the difference of temperature dependent PL spectra before and after microwave heating and discuss the influence of microwave heating on samples. | en_US |