Enhanced photoluminescence of CaTiO3:Pr3+ phosphor films deposited on SiO2 buffered Si substrates

CaTiO3:Pr3+ films have been prepared by pulsed-laser deposition method on SiO2-buffered Si substrates, and their microstructure and photoluminescence properties have been compared with those of the films deposited directly on bare Si substrates. The SiO2 buffer layers were prepared using thermal oxidization and HF-etching. Photoluminescence intensities of CaTiO3:Pr3+ films on the SiO2-buffered Si substrates are significantly higher (up to 800%) than those of the films on bare Si substrates, which is attributed to the low refractive index and low light absorption of the SiO2 buffer layer. This study reveals that the presence of the buffer layer is effective in improving the red emission brightness of CaTiO3:Pr3+ films without sacrificing the surface roughness.