Enhanced photoluminescence of CaTiO3:Pr 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.