Investigation of photoluminescence of Si−O−C(−H) ceramics at an early stage of decarbonization by using high energy excitation

Si−O−C(−H) ceramics with reduced carbon contents were prepared by pyrolyzing polysiloxane particles in hydrogen at temperatures of 750, 800 and 850 °C. Under HeCd laser irradiation (325 nm), the obtained ceramics show broad spectra peaking at 400–415 nm. On the other hand, the excitation on the higher energy region by an ArF excimer laser (193 nm) induces new PL bands located at short wavelength region of 300 and 355 nm. Such high energy PL bands appear prominently in the ceramics synthesized at 750 °C, and are minor in ceramics synthesized at 800 and 850 °C.